CN117659648A - A highly transparent and high-barrier PET/MXD6 composite material and its preparation method and blending bottle - Google Patents

Abstract

The invention discloses a highly transparent and high-barrier PET/MXD6 composite material, a preparation method thereof and a blending bottle. The composite material contains the following components by weight: 70-90 parts of polyethylene terephthalate PET, 10-30 parts of nylon MXD6, 3-7 parts of compatibilizer PET-MXD6 block copolymer, and 0.1-part of antioxidant. 0.5 parts, mica flakes 0.5-2 parts, toughening agent 0.5-3 parts. The carboxyl-terminated PET prepolymer and the amino-terminated MXD6 prepolymer are reacted through an amidation reaction to generate a compatibilizer PET-MXD6 block copolymer. The compatibilizer enables MXD6 to be evenly dispersed in the PET matrix and maintains the transparency of the PET material. At the same time, the barrier properties of PET materials are further improved. The PET/MXD6 composite material is injection molded to form a bottle preform, and then the bottle preform is blow molded to obtain a highly transparent and high-barrier PET/MXD6 blend bottle.

Description

High-transparency high-barrier PET/MXD6 composite material, preparation method thereof and blending bottle

Technical Field

The invention relates to the technical field of high polymer materials for packaging, in particular to a high-transparency high-barrier PET/MXD6 composite material and a blending bottle.

Background

PET, polyethylene terephthalate, belongs to crystalline saturated polyesters, is a milky or pale yellow, highly crystalline polymer, and is the most predominant species in thermoplastic polyesters. PET has excellent creep resistance, fatigue resistance, abrasion resistance, dimensional stability and the like. The end uses of PET are very wide, with the most widespread use in the packaging bottle field, from the original carbonic acid gas bottle to beer bottles, edible oil bottles, pharmaceutical bottles, cosmetic bottles, etc. Although the gas barrier property of PET is far higher than that of plastics such as polyethylene, polypropylene and the like, the PET still can not meet the requirements for products with harsh freshness preservation and flavor preservation such as beer, white spirit, perfume and the like. Therefore, improvement of barrier properties of PET bottles has become a key to research.

MXD6, poly (m-xylylene adipamide) is a crystalline nylon resin, has low water absorption, high heat distortion temperature, high tensile strength and bending strength and small molding shrinkage, and can be used as engineering structural materials in the fields of automobiles, bathrooms, sports and the like; in addition, the MXD6 material has good barrier property to gases such as oxygen, carbon dioxide, water vapor and the like, so that the material is particularly suitable for the packaging field. The MXD6 with excellent barrier property and PET are used for melt blending, so that the barrier property of the PET can be improved, but the haze is increased after direct blending due to poor compatibility of PET and MXD6 materials, and the transparency and color of the product are affected.

The patent CN114410074A adopts 70-85 parts of PET, 6 8-15 parts of MXD and 4-10 parts of PEI for melt blending, realizes the heat resistance of the PET material through MXD6 blending, and ensures the transparency of the PET material; the transesterification is realized mainly by melt blending PEI and PET, the main structure of the PET is changed to ensure that the PET has better compatibility with MXD6, but the transesterification efficiency is lower by a screw, the uniformity of the transesterification cannot be ensured, and finally the blending performance of the PET and the MXD6 can be influenced. The method for increasing the barrier property of PET disclosed in patent CN116063832A adopts the scheme that 70-80 parts of PET, 20-30 parts of polylactic acid, 1-5 parts of nano titanium dioxide, 3-5 parts of antioxidant, 1-2 parts of nano calcium carbonate and 1-1.5 parts of silane coupling agent are blended, and 0.1-0.5 part of graphene oxide compound is used as a filler, and the graphene oxide, the calcium carbonate and the titanium dioxide are mutually cooperated and uniformly distributed in the material, so that the permeation path of water oxygen molecules is prolonged, the barrier property of the product is improved, but the inorganic filler is not transparent, a transparent PET material cannot be obtained, and the method is not suitable for being used in packaging bottles. Therefore, improving the barrier properties of PET by blending MXD6/PET while ensuring the transparency of the composite is a problem to be solved.

Disclosure of Invention

The invention aims to prepare a high-transparency high-barrier PET/MXD6 composite material and a blending bottle.

The main technical problem faced by the invention is to realize that nylon MXD6 is uniformly dispersed in a PET matrix, and the boundary does not exist in the microscopic dimension, so that a uniform single-phase state is formed.

In order to solve the technical problems, the invention adopts the technical principle that: the invention prepares a PET/MXD6 block copolymer by amidation reaction of carboxyl end capped PET prepolymer and amino end capped nylon MXD6 prepolymer. Because the two block structures and the main body structures in the two blends are consistent, the MXD6 in the blend can be partially compatible with the MXD6 block in the block structure, and the PET in the blend can be partially compatible with the PET block in the block structure, so that the blend realizes small-size uniform winding distribution of the two blended products through the block structure, and can show a homogeneous state without boundary on a microscopic scale, so that the PET has excellent barrier performance of the MXD6 and the transparency of the PET is not changed.

Therefore, in order to achieve the above object, the present invention adopts the following technical scheme:

the high-transparency high-barrier PET/MXD6 composite material comprises the following components in parts by weight: 70-90 parts of polyethylene terephthalate (PET), 10-30 parts of nylon MXD6, 3-7 parts of compatilizer PET-MXD6 segmented copolymer, 0.1-0.5 part of antioxidant, 0.5-2 parts of mica sheet and 0.5-3 parts of toughening agent.

In some examples, the preparation method of the high-transparency high-barrier PET/MXD6 composite material comprises the following steps:

adding PET, MXD6, a compatilizer PET-MXD6 segmented copolymer, an antioxidant, mica flakes and a toughening agent into a blender respectively, mixing for 3-10min to obtain a blend, carrying out melt blending extrusion on the blend by using a double-screw extruder, and then granulating and drying to prepare the PET/MXD6 composite slice.

The invention also provides a preparation method of the PET/MXD6 blend bottle, which comprises the following steps: and (3) injection molding the PET/MXD6 composite slice to form a bottle blank, and then blow molding the bottle blank to obtain the PET/MXD6 blend bottle with high transparency and high barrier.

In some examples, it is preferred that the PET has a relative viscosity of 0.6-0.85 (phenol-1, 2-tetrachloroethane = 1:1 (w/w) as solvent, 0.005g/ml concentration), more preferably 0.75.

In some examples, it is preferred that nylon MXD6 have a relative viscosity of 1.9-4.0 (96% concentrated sulfuric acid as solvent, 0.01g/ml concentration), preferably 2.2-3.8.

In some examples, the compatibilizer PET/MXD6 block copolymer is formed from a carboxyl terminated PET prepolymer and an amino terminated nylon MXD6 prepolymer by an amidation reaction, and the preparation method comprises the following steps:

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: adding m-xylylenediamine, adipic acid, an organic diamine end-capping agent and water in a certain proportion into a reaction kettle, replacing with nitrogen for 3-6 times, heating to 80-100 ℃ and maintaining for 30-50min to complete the salt formation reaction of MXD 6; heating to 220-240 ℃ after salification is completed, and maintaining the pressure at 1.5-2MPa; then slowly releasing pressure to normal pressure, heating the material to 250-270 ℃, vacuumizing and carrying out polycondensation reaction for 20-40min, thus finishing the polycondensation reaction and keeping the molten state of the material.

Preferably, in the method, the molar ratio of m-xylylenediamine to adipic acid is preferably in the range of 1 to 1.001.

Preferably, the end-capping agent organic diamine is one or more of m-xylylenediamine, p-xylylenediamine, butanediamine, hexamethylenediamine, decanediamine, dodecanediamine and other organic diamines.

Preferably, the addition amount of the end capping agent is 2.8 to 10.3% of the sum of the mass of m-xylylenediamine and adipic acid.

Preferably, the water is ultrapure water added in an amount of 10 to 80% by mass, more preferably 20 to 70% by mass of the total mass.

Preferably, the nylon MXD6 oligomer prepared has a number average molecular weight of 1000 to 2800.

(2) Carboxyl-terminated PET prepolymer preparation: adding terephthalic acid (PTA), ethylene glycol (MEG) and a catalyst in a certain proportion into a reaction kettle to replace nitrogen for 3-6 times by adopting a direct esterification process route, heating to 200-230 ℃ and keeping for 1-3 hours for esterification, after the water yield reaches 95% of a theoretical value, finishing esterification, continuously raising the temperature to 240-260 ℃ and vacuumizing to ensure that the absolute pressure of a reaction system is reduced to below 100Pa, and continuously reacting for 0.5-2 hours to finish polycondensation and keep a molten state;

preferably, the catalyst is one or more of tetrabutyl titanate, tetraethyl titanate and tetraisopropyl titanate; the catalyst is added in an amount of 0.1 to 2% by weight, more preferably 0.2 to 1% by weight, based on the total mass of the carboxyl-terminated PET prepolymer.

Preferably, the carboxyl-terminated PET prepolymer prepared has a number average molecular weight of 1100-2500.

Preferably, in the preparation of the carboxyl end-capped PET prepolymer, the molar ratio of terephthalic acid to ethylene glycol is 1.08-1.20.

(3) Preparation of compatibilizer PET/MXD6 block copolymer: mixing the molten amino end capped nylon MXD6 prepolymer with the carboxyl end capped PET prepolymer in a reaction kettle, simultaneously adding a proper amount of molecular weight regulator, replacing with nitrogen, maintaining the temperature of the materials at 250-270 ℃, vacuumizing to reduce the absolute pressure of the reaction system to below 1kPa, continuing to react for 40-60min to make the carboxyl end capped PET prepolymer and the amino end capped MXD6 prepolymer perform amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating.

The mole number of the carboxyl end-capped PET prepolymer and the mole number of the amino end-capped nylon MXD6 prepolymer in the reaction kettle are 1:1.

The number average molecular weight of the compatilizer PET/MXD6 block copolymer is 6000-15000.

Preferably, the molecular weight regulator is selected from one or more of adipic acid, sebacic acid, dodecanedioic acid, benzoic acid and lauric acid, preferably adipic acid, and the addition amount is 1.05-2.50% of the total mass of the MXD6/PET block copolymer.

In some examples, the antioxidant disclosed by the invention is selected from one or more of antioxidant 1010, antioxidant 1098, antioxidant 168 and antioxidant H10, and preferably a 1:1 equal mass compounding system of antioxidant 1010 and antioxidant 168.

In some examples, the blender used in the PET/MXD6 composite preparation method has a rotational speed of 20-100rpm, a temperature of 10-40℃and a mixing time of 3-10min.

In some examples, the twin screw extruder used in the process for preparing the PET/MXD6 composite material has a screw temperature set in the range of 240-280 ℃, preferably 250-270 ℃, and a screw speed in the range of 50-400rpm, preferably 100-300rpm.

In some examples, the mica flakes may increase the thermal stability of the bottle after molding.

In some examples, the PET toughening agent is used to increase the toughness of the body. The toughening agent is selected from one or two of ethylene-methyl acrylate copolymer or ethylene butyl acrylate copolymer.

In some examples, MXD6 in the PET/MXD6 composite slice is uniformly dispersed in a PET matrix.

In some examples, in the preparation step of the PET/MXD6 blend bottle, the PET/MXD6 composite slice is heated to 140-170 ℃ for drying for 3-5 h, then the PET/MXD6 composite slice is heated to 275-285 ℃ for melting, the molten material is injected into a mold, the glue injection rate is 55-60 g/s, and the mixture is cooled and demoulded to form a bottle blank.

In some examples, in the step of preparing the PET/MXD6 blend bottle, the bottle embryo is placed into an oven at 130-150 ℃ for 3s-5s; then conveying the preheated bottle embryo to a blow molding machine, and pre-blowing low-pressure air of 1-1.5MPa to expand the bottle embryo to 75% of deformation; and then carrying out 4-6MPa high-pressure blow molding and pressure maintaining for 2-3 s, so that the bottle blank is completely contacted with the inner wall of the die, and cooling and shaping to obtain the PET/MXD6 blended bottle.

Compared with the prior art, the invention has the main advantages that: the invention prepares a PET/MXD6 block copolymer by amidation reaction of carboxyl end capped PET prepolymer and amino end capped nylon MXD6 prepolymer. The segmented copolymer can be used as a compatilizer to improve the compatibility of the MXD6/PET blend, so that the disperse phase MXD6 can be uniformly distributed in the PET main phase, the small-size uniform winding distribution of the two-phase main material is realized, the homogeneous state without boundary is shown on the microscopic size, and the PET has the excellent barrier performance of the MXD6 without changing the transparency of the PET, thereby preparing the PET/MXD6 blend bottle with high barrier and high transparency.

Detailed Description

The invention will now be further illustrated by means of specific examples which are given solely by way of illustration of the invention and do not limit the scope thereof.

The raw materials are as follows:

PET1: manufacturer's korea SK, brands BL8450, BL8050;

PET2, duPont, manufacturer, brands FR530, FR515, FR330;

MXD6: mitsubishi gas chemical corporation, trade mark S6007;

adipic acid: waffle chemistry, industrial grade;

hexamethylenediamine: henan Shenma, industrial grade;

m-xylylenediamine: mitsubishi gas chemical corporation, industrial grade;

decamethylene diamine: industry grade, shandong chemical Co., ltd;

p-xylylenediamine, butanediamine, dodecanediamine: enokava, inc, reagent grade;

tetrabutyl titanate catalyst: enokava, inc, reagent grade;

antioxidants 1098 and 168: manufacturer basf, industrial grade;

mica sheet: anhui Rui light, industrial grade;

toughening agent 1: ethylene methyl acrylate copolymer, trade name of Akema AX8900

Toughening agent 2: ethylene butyl acrylate, duPont PTW

Compatibilizer 1: acoma 4503 terpolymer compatibilizers

The testing method comprises the following steps:

(1) Number average molecular weight test: testing is performed according to GB/T21863-2008 test standard. The mobile phase is hexafluoroisopropanol.

(2) PET/MXD6 blend pellet Scanning Electron Microscope (SEM) test: the test was performed according to GB/T16594-94 test standard. The PET/MXD6 blend bars were brittle-cut in liquid nitrogen, then metal sprayed and cross-section observed using a scanning electron microscope (JSG-5900 LV, japan).

(3) Light transmittance test: the test was performed according to ISO 13468-1 test standard.

(4) Tensile property test: the stretching rate was 50mm/min, tested according to ISO527-1 test standard.

(5) Oxygen transmission rate test: the test was performed according to ISO 15105-2 test standard.

(6) Carbon dioxide transmittance test: testing is carried out according to GB/T1038-2000 test standard.

[ preparation example 1 ]

The PET/MXD6 block copolymer was prepared according to the following procedure

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: 1495.37g of m-xylylenediamine, 1604.63g of adipic acid, 318.99g of hexamethylenediamine and 1026g of water are added into a reaction kettle to be replaced by nitrogen for 3 times, and the mixture is heated to 100 ℃ and kept for 30min to complete the salt formation reaction of MXD 6; heating to 220 ℃ after salt formation is completed, and maintaining the pressure at 1.5MPa; then slowly releasing pressure to normal pressure, heating the material to 250 ℃, vacuumizing and carrying out polycondensation reaction for 40min, thus finishing the polycondensation reaction and keeping the molten state of the material. The nylon MXD6 prepolymer prepared had a number average molecular weight of 1080.

(2) Carboxyl-terminated PET prepolymer preparation: 2371.36g of terephthalic acid (PTA), 851.88g of ethylene glycol (MEG) and 0.64g of tetrabutyl titanate are added into a reaction kettle to be replaced by nitrogen for 3 times, the temperature is raised to 200 ℃ and kept for 3 hours for esterification, after the water yield reaches 95% of the theoretical value, the esterification is finished, the temperature is continuously raised to 260 ℃ and the absolute pressure of the reaction system is reduced to below 100Pa by vacuumizing, the polycondensation is continuously carried out for 0.5 hour, and the melt state is kept. The carboxyl-terminated PET prepolymer prepared had a number average molecular weight of 1110.

(3) Preparation of compatibilizer PET/MXD6 block copolymer: the molten amino-terminated nylon MXD6 prepolymer is discharged into a reaction kettle filled with carboxyl-terminated PET prepolymer through nitrogen pressure, 148.25g of adipic acid is added at the same time, after 3 times of nitrogen replacement, the temperature of the material is maintained at 260 ℃, vacuum pumping is carried out to reduce the absolute pressure of a reaction system to below 1kPa, the reaction is continued for 50 minutes, the carboxyl-terminated PET prepolymer and the amino-terminated MXD6 prepolymer are subjected to amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating are carried out. The number average molecular weight of the obtained block copolymer was 6640.

[ preparation example 2 ]

The PET/MXD6 block copolymer was prepared according to the following procedure

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: 1544.38g of m-xylylenediamine, 1656.39g of adipic acid, 308.87g of p-xylylenediamine and 702g of water are added into a reaction kettle to be replaced by nitrogen for 3 times, and the mixture is heated to 90 ℃ and kept for 40min to complete the salt formation reaction of MXD 6; heating to 230 ℃ after salt formation is completed, and maintaining the pressure at 1.8MPa; then slowly releasing pressure to normal pressure, heating the material to 260 ℃, vacuumizing and carrying out polycondensation reaction for 30min, thus finishing the polycondensation reaction and keeping the molten state of the material. The nylon MXD6 prepolymer prepared had a number average molecular weight of 1350.

(2) Carboxyl-terminated PET prepolymer preparation: 4550.50g of terephthalic acid, 1688.38g of ethylene glycol (MEG) and 1.87g of tetrabutyl titanate are added into a reaction kettle to be replaced by nitrogen for 3 times, the temperature is raised to 210 ℃ and kept for 2.5 hours for esterification, after the water yield reaches 95% of the theoretical value, the esterification is finished, the temperature is continuously raised to 245 ℃ and the absolute pressure of the reaction system is reduced to below 100Pa by vacuumizing, the reaction is continued for 1.5 hours, and the polycondensation reaction is completed, and the molten state is kept. The number average molecular weight of the prepared carboxyl-terminated PET prepolymer was 2450.

(3) Preparation of compatibilizer PET/MXD6 block copolymer: the molten amino-terminated nylon MXD6 prepolymer is discharged into a reaction kettle filled with carboxyl-terminated PET prepolymer through nitrogen pressure, 121.76g of adipic acid is added at the same time, after 3 times of nitrogen replacement, the material temperature is maintained at 255 ℃, vacuum pumping is carried out to reduce the absolute pressure of a reaction system to below 1kPa, the reaction is continued for 55 minutes, the carboxyl-terminated PET prepolymer and the amino-terminated MXD6 prepolymer are subjected to amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating are carried out. The number average molecular weight of the obtained block copolymer was 11540.

[ preparation example 3 ]

The PET/MXD6 block copolymer was prepared according to the following procedure

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: 1882.66g of m-xylylenediamine, 2018.73g of adipic acid, 188.05g of m-xylylenediamine and 1636g of water are added into a reaction kettle to be replaced by nitrogen for 3 times, and the mixture is heated to 85 ℃ and kept for 45min to complete the MXD6 salification reaction; heating to 220 ℃ after salt formation is completed, and maintaining the pressure at 1.5MPa; then slowly releasing pressure to normal pressure, heating the material to 255 ℃, vacuumizing and carrying out polycondensation reaction for 35min, thus finishing the polycondensation reaction and keeping the molten state of the material. The nylon MXD6 prepolymer prepared had a number average molecular weight of 2580.

(2) Carboxyl-terminated PET prepolymer preparation: 1415.17g of terephthalic acid, 514.43g of ethylene glycol and 1.54g of tetraethyl titanate are added into a reaction kettle to be replaced by nitrogen for 3 times, the temperature is raised to 215 ℃ and kept for 2.5 hours for esterification, after the water yield reaches 95% of the theoretical value, the esterification is finished, the temperature is continuously raised to 245 ℃ and the absolute pressure of a reaction system is reduced to below 100Pa by vacuumizing, the polycondensation reaction is continuously carried out for 1.5 hours, and the molten state is kept. The carboxyl-terminated PET prepolymer prepared had a number average molecular weight of 1300.

(3) Preparation of compatibilizer PET/MXD6 block copolymer: the molten amino-terminated nylon MXD6 prepolymer is discharged into a reaction kettle filled with carboxyl-terminated PET prepolymer through nitrogen pressure, 111.30g of adipic acid is added at the same time, after 3 times of nitrogen replacement, the temperature of the material is maintained at 250 ℃, vacuum pumping is carried out to reduce the absolute pressure of a reaction system to below 1kPa, the reaction is continued for 60 minutes, the carboxyl-terminated PET prepolymer and the amino-terminated MXD6 prepolymer are subjected to amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating are carried out. The number average molecular weight of the obtained block copolymer was 7880.

[ PREPARATION EXAMPLE 4 ]

The PET/MXD6 block copolymer was prepared according to the following procedure

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: 1833.48g of m-xylylenediamine, 1966.97g of adipic acid, 107.93g of butanediamine and 2345g of water are added into a reaction kettle to be replaced by nitrogen for 3 times, and the mixture is heated to 95 ℃ and kept for 35min to complete the salt formation reaction of MXD 6; heating to 225 ℃ after salt formation is completed, and maintaining the pressure at 1.7MPa; then slowly releasing pressure to normal pressure, heating the material to 265 ℃, vacuumizing and carrying out polycondensation reaction for 25min, thus finishing the polycondensation reaction and keeping the molten state of the material. The number average molecular weight of the prepared nylon MXD6 prepolymer was 2790.

(2) Carboxyl-terminated PET prepolymer preparation: 2254.50g of terephthalic acid (PTA), 835.40g of ethylene glycol and 1.54g of tetraisopropyl titanate are added into a reaction kettle to be replaced by nitrogen for 3 times, the temperature is raised to 220 ℃ and kept for 2 hours for esterification, after the water yield reaches 95% of the theoretical value, the esterification is finished, the temperature is continuously raised to 250 ℃ and the absolute pressure of a reaction system is reduced to below 100Pa by vacuumizing, the polycondensation reaction is continuously carried out for 1 hour, and the molten state is kept. The number average molecular weight of the prepared carboxyl-terminated PET prepolymer was 2270.

(3) Preparation of compatibilizer PET/MXD6 block copolymer: the molten amino-terminated nylon MXD6 prepolymer is discharged into a reaction kettle filled with carboxyl-terminated PET prepolymer through nitrogen pressure, 65.73g of adipic acid is added at the same time, after 3 times of nitrogen replacement, the material temperature is maintained at 255 ℃, vacuum pumping is carried out to reduce the absolute pressure of a reaction system to below 1kPa, the reaction is continued for 55 minutes, the carboxyl-terminated PET prepolymer and the amino-terminated MXD6 prepolymer are subjected to amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating are carried out. The number average molecular weight of the obtained block copolymer was 15260.

[ preparation example 5 ]

The PET/MXD6 block copolymer was prepared according to the following procedure

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: 1689.43g of m-xylylenediamine, 1811.68g of adipic acid, 310.55g of dodecanediamine and 2668g of water are added into a reaction kettle to be replaced by nitrogen for 3 times, and the mixture is heated to 80 ℃ and kept for 50min to complete the salt formation reaction of MXD 6; after salt formation is completed, heating to 240 ℃, and maintaining the pressure to 2MPa; then slowly releasing pressure to normal pressure, heating the material to 270 ℃, vacuumizing and carrying out polycondensation reaction for 20min, thus finishing the polycondensation reaction and keeping the molten state of the material. The nylon MXD6 prepolymer prepared had a number average molecular weight of 2150.

(2) Carboxyl-terminated PET prepolymer preparation: 1838.83g of terephthalic acid, 673.26g of ethylene glycol (MEG) and 2.51g of tetrabutyl titanate are added into a reaction kettle to be replaced by nitrogen for 3 times, the temperature is raised to 225 ℃ and kept for 2 hours for esterification, after the water yield reaches 95% of the theoretical value, the esterification is finished, the temperature is continuously raised to 255 ℃ and the absolute pressure of the reaction system is reduced to below 100Pa by vacuumizing, the polycondensation reaction is continuously carried out for 1 hour, and the molten state is kept. The number average molecular weight of the prepared carboxyl terminated PET prepolymer is 1490.

(3) Preparation of compatibilizer PET/MXD6 block copolymer: the molten amino-terminated nylon MXD6 prepolymer is discharged into a reaction kettle filled with carboxyl-terminated PET prepolymer through nitrogen pressure, 83.24g of adipic acid is added at the same time, after 3 times of nitrogen replacement, the temperature of the material is maintained at 260 ℃, vacuum pumping is carried out to reduce the absolute pressure of a reaction system to below 1kPa, the reaction is continued for 50 minutes, the carboxyl-terminated PET prepolymer and the amino-terminated MXD6 prepolymer are subjected to amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating are carried out. The number average molecular weight of the obtained block copolymer was 11050.

[ preparation example 6 ]

The PET/MXD6 block copolymer was prepared according to the following procedure

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: 1592.80g of m-xylylenediamine, 1708.16g of adipic acid, 335.71g of decanediamine and 1818g of water are added into a reaction kettle to be replaced by nitrogen for 3 times, and the mixture is heated to 100 ℃ and kept for 30min to complete the salt formation reaction of MXD 6; heating to 220 ℃ after salt formation is completed, and maintaining the pressure at 1.5MPa; then slowly releasing pressure to normal pressure, heating the material to 265 ℃, vacuumizing and carrying out polycondensation reaction for 25min, thus finishing the polycondensation reaction and keeping the molten state of the material. The nylon MXD6 prepolymer prepared had a number average molecular weight of 1632.

(2) Carboxyl-terminated PET prepolymer preparation: 2629.53g of terephthalic acid, 967.30g of ethylene glycol and 2.52g of tetrabutyl titanate are added into a reaction kettle to be replaced by nitrogen for 3 times, the temperature is raised to 230 ℃ and kept for 1 hour for esterification, after the water yield reaches 95% of the theoretical value, the esterification is finished, the temperature is continuously raised to 260 ℃ and the absolute pressure of a reaction system is reduced to below 100Pa by vacuumizing, the polycondensation is continuously carried out for 0.5 hour, and the molten state is kept. The number average molecular weight of the prepared carboxyl-terminated PET prepolymer was 1690.

(3) Preparation of compatibilizer PET/MXD6 block copolymer: the molten amino-terminated nylon MXD6 prepolymer is discharged into a reaction kettle filled with carboxyl-terminated PET prepolymer through nitrogen pressure, 78.47g of adipic acid is added at the same time, after nitrogen is replaced for 3 times, the temperature of the material is maintained at 270 ℃, vacuum is pumped to reduce the absolute pressure of a reaction system to below 1kPa, the reaction is continued for 40 minutes, the carboxyl-terminated PET prepolymer and the amino-terminated MXD6 prepolymer are subjected to amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating are carried out. The number average molecular weight of the obtained block copolymer was 13420.

[ preparation example 7 ]

The PET/MXD6 block copolymer was prepared according to the following procedure

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: 1640.08g of m-xylylenediamine, 1759.92g of adipic acid, 199.92g of hexamethylenediamine and 2520g of water are added into a reaction kettle to be replaced by nitrogen for 3 times, and the mixture is heated to 95 ℃ and kept for 35min to complete the salt formation reaction of MXD 6; heating to 235 ℃ after salt formation is completed, and maintaining the pressure at 1.9MPa; then slowly releasing pressure to normal pressure, heating the material to 250 ℃, vacuumizing and carrying out polycondensation reaction for 40min, thus finishing the polycondensation reaction and keeping the molten state of the material. The nylon MXD6 prepolymer prepared had a number average molecular weight of 1820.

(2) Carboxyl-terminated PET prepolymer preparation: 2604.02g of terephthalic acid, 961.02g of ethylene glycol and 1.43g of tetrabutyl titanate are added into a reaction kettle to be replaced by nitrogen for 3 times, the temperature is raised to 200 ℃ and kept for 3 hours for esterification, after the water yield reaches 95% of the theoretical value, the esterification is finished, the temperature is continuously raised to 240 ℃ and the absolute pressure of a reaction system is reduced to below 100Pa by vacuumizing, the polycondensation reaction is continuously carried out for 2 hours, and the molten state is kept. The number average molecular weight of the prepared carboxyl-terminated PET prepolymer was 1880.

(3) Preparation of compatibilizer PET/MXD6 block copolymer: the molten amino-terminated nylon MXD6 prepolymer is discharged into a reaction kettle filled with carboxyl-terminated PET prepolymer through nitrogen pressure, 92.41g of adipic acid is added at the same time, after nitrogen is replaced for 3 times, the temperature of the material is maintained at 260 ℃, vacuum is pumped to reduce the absolute pressure of a reaction system to below 1kPa, the reaction is continued for 50 minutes, the carboxyl-terminated PET prepolymer and the amino-terminated MXD6 prepolymer are subjected to amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating are carried out. The number average molecular weight of the obtained block copolymer was 11230.

[ preparation example 8 ]

The PET/MXD6 block copolymer was prepared according to the following procedure

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: 1736.56g of m-xylylenediamine, 1863.44g of adipic acid, 124.92g of butanediamine and 1676g of water are added into a reaction kettle to be replaced by nitrogen for 3 times, and the mixture is heated to 100 ℃ and kept for 30min to complete the salt formation reaction of MXD 6; heating to 230 ℃ after salt formation is completed, and maintaining the pressure at 1.8MPa; then slowly releasing pressure to normal pressure, heating the material to 260 ℃, vacuumizing and carrying out polycondensation reaction for 30min, thus finishing the polycondensation reaction and keeping the molten state of the material. The number average molecular weight of the nylon MXD6 prepolymer prepared was 2280.

(2) Carboxyl-terminated PET prepolymer preparation: 2377.24g of terephthalic acid, 879.37g of ethylene glycol and 2.93g of tetrabutyl titanate are added into a reaction kettle to be replaced by nitrogen for 3 times, the temperature is raised to 220 ℃ and kept for 2 hours for esterification, after the water yield reaches 95% of the theoretical value, the esterification is finished, the temperature is continuously raised to 245 ℃ and the absolute pressure of the reaction system is reduced to below 100Pa by vacuumizing, the polycondensation reaction is continuously carried out for 1.5 hours, and the molten state is kept. The number average molecular weight of the prepared carboxyl-terminated PET prepolymer was 2070.

(3) Preparation of compatibilizer PET/MXD6 block copolymer: the molten amino-terminated nylon MXD6 prepolymer is discharged into a reaction kettle filled with carboxyl-terminated PET prepolymer through nitrogen pressure, 114.15g of adipic acid is added at the same time, after 3 times of nitrogen replacement, the material temperature is maintained at 255 ℃, vacuum pumping is carried out to reduce the absolute pressure of a reaction system to below 1kPa, the reaction is continued for 55min, the carboxyl-terminated PET prepolymer and the amino-terminated MXD6 prepolymer are subjected to amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating are carried out. The number average molecular weight of the obtained block copolymer was 8830.

Example 1

PET/MXD6 blend bottles were prepared as follows:

(1) PET/MXD6 composite slice preparation steps: 9kg of polyethylene terephthalate (BL 8450), 1kg of nylon MXD6, 300g of the compatilizer PET-MXD6 block copolymer prepared in the preparation example 1, 10g of a compound antioxidant (an equal mass compound of an antioxidant 1010 and an antioxidant 168), 50g of mica sheet and 50g of a toughening agent 1 are added into a blender, mixed for 5min at a speed of 60rpm and a speed of 20 ℃, and then the mixture is fed into a screw extruder for melt blending extrusion, water cooling, granulating and drying to prepare PET/MXD6 blended granules, wherein the screw temperature is 260 ℃ and the rotational speed is 200rpm.

(2) And (3) preparing a blending bottle: and (3) heating the PET/MXD6 composite slice prepared in the step (1) to 150 ℃ for drying for 3.5 hours, then heating the PET/MXD6 composite slice to 275 ℃ for melting, injecting the melted material into a mold, injecting glue at a rate of 55g/s, cooling, and demolding to form a packaging bottle blank. Preheating the bottle embryo, reducing stress, providing plasticity for stretching, and placing the bottle embryo into a 130 ℃ oven for 5s; then conveying the preheated bottle embryo to a blow molding machine, and pre-blowing low-pressure air of 1.2MPa to expand the bottle embryo to 75% of deformation; and then carrying out 5MPa high-pressure blow molding and pressure maintaining for 3s, so that the bottle blank is completely contacted with the inner wall of the mold, and cooling to obtain the PET/MXD6 blending bottle.

Example 2

PET/MXD6 blend bottles were prepared as follows:

(1) PET/MXD6 composite slice preparation steps: 9kg of polyethylene terephthalate (BL 8450), 1kg of nylon MXD6, 400g of the compatilizer PET-MXD6 block copolymer prepared in the preparation example 2, 30g of a compound antioxidant (an equal mass compound of an antioxidant 1010 and an antioxidant 168), 100g of mica sheet and 100g of a toughening agent 1 are added into a blender, mixed for 5min at the rotating speed of 80rpm and the temperature of 30 ℃, and then the mixture is fed into a screw extruder for melt blending extrusion, water cooling, granulating and drying to prepare PET/MXD6 compound granules, wherein the screw temperature is 250 ℃ and the rotating speed is 250rpm.

(2) And (3) preparing a blending bottle: and (3) heating the PET/MXD6 composite slice prepared in the step (1) to 140 ℃ for drying for 5 hours, then heating the PET/MXD6 composite slice to 280 ℃ for melting, injecting the melted material into a mold, injecting glue at a rate of 58g/s, cooling, and demolding to form a packaging bottle blank. Preheating the bottle embryo, reducing stress, providing plasticity for stretching, and placing the bottle embryo into a 140 ℃ oven for 3s; then conveying the preheated bottle embryo to a blow molding machine, and pre-blowing low-pressure air of 1.3MPa to expand the bottle embryo to 75% of deformation; and then carrying out 5MPa high-pressure blow molding and pressure maintaining for 2s, so that the bottle blank is completely contacted with the inner wall of the die, and cooling to obtain the PET/MXD6 blending bottle.

Example 3

PET/MXD6 blend bottles were prepared as follows:

(1) PET/MXD6 composite slice preparation steps: 8kg of polyethylene terephthalate (FR 530), 2kg of nylon MXD6, 300g of the compatibilizer PRT-MXD6 block copolymer in preparation example 3, 50g of a compound antioxidant (an equal mass compound of antioxidant 1010 and antioxidant 168), 150g of mica sheet and 120g of toughener 2 were added into a blender, mixed for 8 minutes at a rotation speed of 90rpm and a temperature of 35 ℃, and then the mixture was fed into a screw extruder, and melt blending extrusion, water cooling, granulating and drying were performed to prepare PET/MXD6 compound granules, wherein the screw temperature was 260 ℃ and the rotation speed was 300rpm.

(2) And (3) preparing a blending bottle: and (3) heating the PET/MXD6 composite slice prepared in the step (1) to 160 ℃ for drying for 3.5 hours, then heating the PET/MXD6 composite slice to 280 ℃ for melting, injecting the melted material into a mold, injecting glue at 54g/s, cooling, and demolding to form a packaging bottle blank. Preheating the bottle embryo, reducing stress, providing plasticity for stretching, and placing the bottle embryo into a 135 ℃ oven for 3s; then conveying the preheated bottle embryo to a blow molding machine, and pre-blowing low-pressure air of 1.2MPa to expand the bottle embryo to 75% of deformation; and then carrying out 4.5MPa high-pressure blow molding, and maintaining the pressure for 3s, so that the bottle blank is completely contacted with the inner wall of the mold, and cooling to obtain the PET/MXD6 blended bottle.

Example 4

PET/MXD6 blend bottles were prepared as follows:

(1) PET/MXD6 composite slice preparation steps: 8kg of polyethylene terephthalate (FR 530), 2kg of nylon MXD6, 700g of the compatibilizer PET-MXD6 block copolymer in preparation example 4, 40g of a compound antioxidant (an equal mass compound of antioxidant 1010 and antioxidant 168), 200g of mica sheet and 210g of a toughening agent 2 were added to a blender, mixed for 6 minutes at a rotation speed of 80rpm and a temperature of 30 ℃, and then the mixture was fed to a screw extruder, and melt blending extrusion, water cooling, granulating and drying were carried out to prepare PET/MXD6 compound granules, wherein the screw temperature was 265 ℃ and the rotation speed was 350rpm.

(2) And (3) preparing a blending bottle: and (3) heating the PET/MXD6 composite slice prepared in the step (1) to 150 ℃ for drying for 4 hours, then heating the PET/MXD6 composite slice to 280 ℃ for melting, injecting the melted material into a mold, injecting glue at 57g/s, cooling, and demolding to form a packaging bottle blank. Preheating the bottle embryo, reducing stress, providing plasticity for stretching, and placing the bottle embryo into a 140 ℃ oven for 3s; then conveying the preheated bottle embryo to a blow molding machine, and pre-blowing low-pressure air of 1.5MPa to expand the bottle embryo to 75% of deformation; and then carrying out 5MPa high-pressure blow molding and pressure maintaining for 2s, so that the bottle blank is completely contacted with the inner wall of the die, and cooling to obtain the PET/MXD6 blending bottle.

Example 5

PET/MXD6 blend bottles were prepared as follows:

(1) PET/MXD6 composite slice preparation steps: 7kg of polyethylene terephthalate (BL 8050), 3kg of nylon MXD6, 500g of the compatilizer PRT-MXD6 block copolymer in preparation example 5, 10g of compound antioxidant (equal mass compound of antioxidant 1010 and antioxidant 168), 120g of mica sheet and 150g of toughening agent 1 are added into a blender, mixed for 3min at the temperature of 40 ℃ at the speed of 100rpm, and then the mixture is fed into a screw extruder, and the mixture is subjected to melt blending extrusion, water cooling, granulating and drying to prepare PET/MXD6 compound granules, wherein the screw temperature is 260 ℃ and the rotating speed is 300rpm.

(2) And (3) preparing a blending bottle: and (3) heating the PET/MXD6 composite slice prepared in the step (1) to 140 ℃ for drying for 5 hours, then heating the PET/MXD6 composite slice to 280 ℃ for melting, injecting the melted material into a mold, injecting glue at a rate of 60g/s, cooling, and demolding to form a packaging bottle blank. Preheating the bottle embryo, reducing stress, providing plasticity for stretching, and placing the bottle embryo into a baking oven at 150 ℃ for 3s; then conveying the preheated bottle embryo to a blow molding machine, and pre-blowing low-pressure air of 1.4MPa to expand the bottle embryo to 75% of deformation; and then carrying out 5.5MPa high-pressure blow molding, maintaining the pressure for 2s, so that the bottle blank is completely contacted with the inner wall of the die, and cooling to obtain the PET/MXD6 blended bottle.

Example 6

PET/MXD6 blend bottles were prepared as follows:

(1) PET/MXD6 composite slice preparation steps: 7.5kg of polyethylene terephthalate (FR 515), 2.5kg of nylon MXD6, 500g of the compatilizer PET-MXD6 block copolymer in preparation example 6, 20g of a compound antioxidant (an equal mass compound of antioxidant 1010 and antioxidant 168), 170g of mica sheet and 200g of toughener 2 are added into a blender, mixed for 5min at the temperature of 30 ℃ at the speed of 80rpm, and then the mixture is fed into a screw extruder, and the mixture is subjected to melt blending extrusion, water cooling, granulating and drying to prepare PET/MXD6 compound granules, wherein the screw temperature is 265 ℃ and the rotational speed is 300rpm.

(2) And (3) preparing a blending bottle: and (3) heating the PET/MXD6 composite slice prepared in the step (1) to 150 ℃ for drying for 4 hours, then heating the PET/MXD6 composite slice to 280 ℃ for melting, injecting the melted material into a mold, injecting glue at a rate of 55g/s, cooling, and demolding to form a packaging bottle blank. Preheating the bottle embryo, reducing stress, providing plasticity for stretching, and placing the bottle embryo into a 145 ℃ oven for 3s; then conveying the preheated bottle embryo to a blow molding machine, and pre-blowing low-pressure air of 1.2MPa to expand the bottle embryo to 75% of deformation; and then carrying out 5MPa high-pressure blow molding and pressure maintaining for 2s, so that the bottle blank is completely contacted with the inner wall of the die, and cooling to obtain the PET/MXD6 blending bottle.

Example 7

PET/MXD6 blend bottles were prepared as follows:

(1) PET/MXD6 composite slice preparation steps: 8.5kg of polyethylene terephthalate (FR 330), 1.5kg of nylon MXD6, 400g of the compatibilizer PET-MXD6 block copolymer in preparation example 7, 30g of a compound antioxidant (an equal mass compound of antioxidant 1010 and antioxidant 168), 140g of mica flakes and 300g of a toughening agent 2 were added into a blender, mixed for 6min at a rotation speed of 60rpm and a temperature of 40 ℃, and then the mixture was fed into a screw extruder, and melt blending extrusion, water cooling, granulating and drying were carried out to prepare PET/MXD6 compound granules, wherein the screw temperature was 260 ℃ and the rotation speed was 200rpm.

(2) And (3) preparing a blending bottle: and (3) heating the PET/MXD6 composite slice prepared in the step (1) to 160 ℃ for drying for 3.5 hours, then heating the PET/MXD6 composite slice to 280 ℃ for melting, injecting the melted material into a mold, injecting glue at a rate of 60g/s, cooling, and demolding to form a packaging bottle blank. Preheating the bottle embryo, reducing stress, providing plasticity for stretching, and placing the bottle embryo into a baking oven at 150 ℃ for 3s; then conveying the preheated bottle embryo to a blow molding machine, and pre-blowing low-pressure air of 1.5MPa to expand the bottle embryo to 75% of deformation; and then carrying out 5MPa high-pressure blow molding and pressure maintaining for 2s, so that the bottle blank is completely contacted with the inner wall of the die, and cooling to obtain the PET/MXD6 blending bottle.

Example 8

PET/MXD6 blend bottles were prepared as follows:

(1) PET/MXD6 composite slice preparation steps: 8.2kg of polyethylene terephthalate (BL 8450), 1.8kg of nylon MXD6, 600g of the compatilizer PET-MXD6 block copolymer in preparation example 8, 40g of compound antioxidant (equal mass compound of antioxidant 1010 and antioxidant 168), 180g of mica sheet and 250g of toughener 1 are added into a blender, mixed for 6min at the temperature of 40 ℃ at the rotation speed of 60rpm, and then the mixture is fed into a screw extruder, and the mixture is subjected to melt blending extrusion, water cooling, granulating and drying to prepare PET/MXD6 compound granules, wherein the screw temperature is 260 ℃ and the rotation speed is 200rpm.

(2) And (3) preparing a blending bottle: and (3) heating the PET/MXD6 composite slice prepared in the step (1) to 160 ℃ for drying for 3.5 hours, then heating the PET/MXD6 composite slice to 280 ℃ for melting, injecting the melted material into a mold, injecting glue at a rate of 60g/s, cooling, and demolding to form a packaging bottle blank. Preheating the bottle embryo, reducing stress, providing plasticity for stretching, and placing the bottle embryo into a baking oven at 150 ℃ for 3s; then conveying the preheated bottle embryo to a blow molding machine, and pre-blowing low-pressure air of 1.5MPa to expand the bottle embryo to 75% of deformation; and then carrying out 5MPa high-pressure blow molding and pressure maintaining for 2s, so that the bottle blank is completely contacted with the inner wall of the die, and cooling to obtain the PET/MXD6 blending bottle.

Comparative example 1

The formulation and the bottle blowing method were the same as in example 1 except that the block copolymer of the compatibilizer PET-MXD6 of preparation example 1 was not added.

Comparative example 2

The formulation and the bottle blowing preparation were the same as in example 1 except that 100g of the block copolymer of PET-MXD6 as a compatibilizer in preparation example 1 was added.

Comparative example 3

The formulation and the blow molding preparation method were the same as in example 1 except that 1500g of a block copolymer of PET-MXD6 as a compatibilizer in preparation example 1 was added.

Comparative example 4

The formulation and blow molding process were identical to example 1, except that commercial compatibilizer 1 was used in place of the block copolymer of compatibilizer PET-MXD6 in preparation example 1.

Comparative example 5

The amount of adipic acid as a capping agent in preparation example 1 was reduced to 221.57g, the molecular weight 4490 of the compatibilizing agent was obtained, and other formulations and bottle blowing preparation methods were the same as in example 1,

comparative example 6

The amount of adipic acid as a capping agent in preparation example 1 was reduced to 44.31g to give a compatibilizing agent having a molecular weight 21930, and other formulations and bottle blowing methods were consistent with those of example 1.

Table 1, blends of the above examples and comparative examples, and bottle physical properties characterization

As can be seen from the results of the sizes of the dispersed phases in the examples and the comparative examples in Table 1, the block copolymer PET-MXD6 prepared by the invention can effectively improve the compatibility of PET and MXD6 so as to realize uniform dispersion of MXD6 in the PET matrix, and the homogeneous blend can improve the barrier property and the transparency of PET bottles.

When the PET-MXD6 block copolymer (comparative example 1) is not added or the addition amount of PET-MXD6 is too small (comparative example 2), the compatibilization effect is poor, and MXD6 is randomly dispersed in the PET matrix in different sizes, resulting in deterioration of barrier property and transparency of the product. When the MXD6 addition amount is too high (comparative example 3), a compatibilizer of small molecular weight exists in the system, severely degrading the mechanical properties of the product.

When the compatibilizer 1 was added (comparative example 4), the structure of the compatibilizer 1 was greatly different from MXD6, no obvious compatibilization was observed, and neither the transparency nor barrier properties of the product were improved.

When the molecular weight of the MXD6-PET block copolymer is too small (comparative example 5) or too large (comparative example 6), the intended compatibilizing effect cannot be achieved because of the high mismatch in melt viscosities of the MXD6-PET block copolymer and the matrix resin, and the MXD6 dispersed phase is large in size, and the properties of the corresponding blend and bottle are deteriorated.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and additions may be made to those skilled in the art without departing from the method of the present invention, which modifications and additions are also to be considered as within the scope of the present invention.

Claims (10)

1. The high-transparency high-barrier PET/MXD6 composite material comprises the following components in parts by weight: 70-90 parts of polyethylene terephthalate PET, 10-30 parts of nylon MXD6, 3-7 parts of compatilizer PET-MXD6 segmented copolymer, 0.1-0.5 part of antioxidant, 0.5-2 parts of mica sheet and 0.5-3 parts of toughening agent.

2. The composite material according to claim 1, wherein the PET has a relative viscosity of 0.6-0.85, preferably 0.75, under test conditions of phenol-1, 2-tetrachloroethane = 1:1 (w/w) as solvent, 0.005g/ml concentration.

3. The composite material according to claim 1, wherein the nylon MXD6 has a relative viscosity of 1.9-4.0, preferably 2.2-3.8, tested under conditions of 96wt% concentrated sulfuric acid as solvent, 0.01g/ml concentration.

4. A composite material according to any one of claims 1-3, wherein the compatibilizer PET/MXD6 block copolymer is formed by amidation reaction of a carboxyl terminated PET prepolymer and an amino terminated nylon MXD6 prepolymer, and the method of preparation thereof comprises the steps of:

(1) Preparation of an amino-terminated nylon MXD6 prepolymer: adding m-xylylenediamine, adipic acid, an organic diamine end-capping agent and water in a certain proportion into a reaction kettle for nitrogen replacement, heating to 80-100 ℃ and maintaining for 30-50min to complete the salt formation reaction of MXD 6; heating to 220-240 ℃ after salification is completed, and maintaining the pressure at 1.5-2MPa; then slowly releasing pressure to normal pressure, heating the material to 250-270 ℃, vacuumizing and carrying out polycondensation reaction for 20-40min, thus finishing the polycondensation reaction and keeping the molten state of the material;

(2) Carboxyl-terminated PET prepolymer preparation: adding terephthalic acid, ethylene glycol and a catalyst in a certain proportion into a reaction kettle to replace nitrogen, heating to 200-230 ℃ and keeping for 1-3 hours for esterification, after the water yield reaches 95% of a theoretical value, finishing esterification, continuously raising the temperature to 240-260 ℃ and vacuumizing to reduce the absolute pressure of a reaction system to below 100Pa, and continuously reacting for 0.5-2 hours to finish polycondensation and keep a molten state;

(3) Preparation of compatibilizer PET/MXD6 block copolymer: mixing the molten amino end capped nylon MXD6 prepolymer with the carboxyl end capped PET prepolymer in a reaction kettle, simultaneously adding a proper amount of molecular weight regulator, replacing with nitrogen, maintaining the temperature of the materials at 250-270 ℃, vacuumizing to reduce the absolute pressure of the reaction system to below 1kPa, continuing to react for 40-60min to make the carboxyl end capped PET prepolymer and the amino end capped MXD6 prepolymer perform amidation reaction to obtain a compatilizer PET/MXD6 segmented copolymer, and then discharging and granulating.

5. The composite material according to claim 4, wherein the end-capping agent is one or more of m-xylylenediamine, p-xylylenediamine, butanediamine, hexamethylenediamine, decanediamine, dodecanediamine.

6. The composite material of claim 4, wherein the nylon MXD6 oligomer has a number average molecular weight of 1000 to 2800; the carboxyl-terminated PET prepolymer has a number average molecular weight of 1100-2500.

7. The composite material of claim 4, wherein in step (3), the number of moles of carboxyl terminated PET prepolymer to the number of moles of amino terminated nylon MXD6 prepolymer is 1:1; the number average molecular weight of the compatilizer PET/MXD6 block copolymer is 6000-15000.

8. The composite material according to claim 4, wherein the molecular weight regulator is selected from one or more of adipic acid, sebacic acid, dodecanedioic acid, benzoic acid, lauric acid, preferably adipic acid, and is added in an amount of 1.05-2.50% of the total mass of MXD6/PET block copolymer.

9. A method of preparing the composite material of claim 1, comprising the steps of:

adding PET, MXD6, a compatilizer PET-MXD6 segmented copolymer, an antioxidant, mica flakes and a toughening agent into a blender respectively, mixing for 3-10min to obtain a blend, carrying out melt blending extrusion on the blend by using a double-screw extruder, and then granulating and drying to prepare the PET/MXD6 composite slice.

10. A blend bottle made using the composite of any of claims 1-8.