CN104140524B - Copolyester and preparation method and application thereof - Google Patents

Abstract

The invention discloses a novel copolyester. The polymerized monomers of the copolyester include: (A) one or more kinds selected from aliphatic dibasic acids, naphthenic dibasic acids or their esters and acid anhydrides; (B) one or more are selected from aromatic dibasic acids or their esters, anhydrides; (C) one or more are selected from compounds with amino and hydroxyl functional groups, or their compounds with epoxy, Compounds of derivatives of azacyclic or sulfur heterocyclic rings; the copolyester is prepared by esterification, polycondensation reaction and radiation crosslinking reaction during or after polycondensation after mixing the above-mentioned polymerized monomers. Because the copolyester has a special branched structure, it has excellent melt strength, tear resistance and impact resistance, processing performance and product use performance. The invention also discloses the preparation method and application of the copolyester.

Description

A kind of copolyester and its preparation method and application

technical field

The present invention relates to aliphatic-aromatic copolyester and its preparation method and application, in particular to a novel copolyester which is fully biodegradable and has a special branched structure prepared by radiation crosslinking and its preparation method and application .

Background technique

Plastic has many advantages such as easy molding and processing, bright colors and low price, so it is widely used in various fields of national economy and people's daily life. However, due to the long-term stability of plastics, discarded plastic products will not decompose or rot in nature for hundreds of years, so the "white pollution" of plastic waste has become a worldwide issue. In today's deteriorating environment, how to solve the contradiction between the use of plastic products and environmental damage (such as the pollution of waste plastic films and plastic bags) is becoming more and more important. Therefore, the research and application of various degradable plastics have been widely valued, and the development and application of fully biodegradable plastic products has become a research hotspot worldwide.

In order to solve the pollution problem after discarding chemical plastic films, people have been looking for effective substitutes. The study found that the ideal substitute is a fully biodegradable material, in order to completely solve the problem of non-recyclable waste plastic pollution. Fully biodegradable materials include natural polymer materials and synthetic polymer materials. Due to the difficulty in processing natural polymer materials, synthetic degradable polymer materials have become the mainstream in the development of degradable plastics. Among them, biodegradable polyester is due to its excellent physical properties. , degradation performance and appropriate cost have become the focus of the current development of degradable plastics. Among the currently developed biodegradable polyesters, aliphatic polyesters such as polylactic acid and polybutylene succinate, and copolyesters of aromatic polyesters and aliphatic polyesters are one of the focuses of research and development.

At present, some aliphatic-aromatic copolyesters have been industrialized or patented, such as ZL95196874.2 of BASF in Germany, which discloses an aliphatic-aromatic copolyester whose main feature is the polymerization process Compounds with three functional groups, such as glycerol, are added to the polymer to produce branched crosslinking reactions during the polymerization process, and the industrialization of aliphatic-aromatic copolyesters is first realized. However, this invention also has the problems of uncontrollable cross-linking and uncontrollable branch length, which limits its application in many fields. CN101717493A of Hangzhou Xinfu Pharmaceutical Co., Ltd. of China discloses a kind of aliphatic-aromatic copolyester. After the polymerization is complete, the crosslinking is reinitiated by the olefin initiator. Although the invention can effectively control the crosslinking density, due to the introduction of olefin segments, the product becomes a mixed material of olefin and copolyester, and the compatibility of the polyester matrix and polyolefin affects the mechanical properties of the material. Moreover, since the olefin polymerization must be carried out after the polycondensation of the copolyester is completed, the reaction steps are increased and the process flow is prolonged. In addition, China National Petroleum Corporation CN101864068A also reported a polybutylene terephthalate/butylene adipate copolyester, which is a linear aliphatic-aromatic copolyester.

Although the aliphatic-aromatic copolyesters disclosed above have certain use value in practice, the production process is relatively complicated, and the use performance needs to be further improved to meet the requirements of real life for material performance. The present invention can carry out cross-linking synchronously during the copolyester polymerization process through the radiation in the tank during the polymerization process, so that the cross-linking density of the product is uniform, and the cross-linking density can be controlled by controlling the radiation dose, so the cross-linking density can be obtained relatively easily. Uniform, aliphatic-aromatic copolyester with controllable crosslinking density, simple process, good product performance, meeting the application requirements of processing and products.

Contents of the invention

The technical problem to be solved by the present invention is to provide a novel copolyester with biodegradable, high molecular weight and branched structure.

The technical scheme that the present invention adopts is to provide a kind of novel copolyester, and the polymerization monomer of described copolyester comprises:

(A) one or more compounds in aliphatic dibasic acids, naphthenic dibasic acids or their esters and acid anhydrides;

(B) One or more mixtures of aromatic dibasic acids or their esters and acid anhydrides;

(C) Compounds with amino and hydroxyl functional groups, or one or more compounds in their derivatives with epoxy groups, nitrogen heterocycles or sulfur heterocycles;

The novel copolyester is prepared by mixing the above polymerized monomers through esterification reaction, polycondensation reaction and radiation crosslinking reaction during or after polycondensation.

Preferably, the molar ratio of hydroxyl and carboxyl groups in the polymerized monomer is 0.8 to 5:1 or the molar ratio of amino and carboxyl groups is 0.8 to 5:1 or the sum of the moles of hydroxyl and amino groups to the moles of carboxyl groups The ratio of numbers is 0.8～5:1;

Preferably, the molar ratio of the polymerized monomers (A), (B) and (C) is (10-95):(5-95):(0.0001-10).

Preferably, the number average molecular weight of the copolyester is 10,000-300,000, and the molecular weight distribution is 1.2-6.5.

Preferably, the melting point of the novel copolyester is 30-210°C, and the glass transition temperature is -60-100°C.

Preferably, the aliphatic dibasic acid is selected from C ₂ -C ₃₀ aliphatic dibasic acids, and the cycloalkane dibasic acid is selected from C ₅ -C ₂₀ naphthenic dibasic acids; more preferably, the The aliphatic dibasic acid is selected from C ₂ -C ₁₀ aliphatic dibasic acids, and the cycloalkane dibasic acid is selected from C ₅ -C ₁₀ cycloalkyl dibasic acids; more preferably, the aliphatic dibasic acid The acid is selected from C ₂ -C ₆ aliphatic dibasic acids, the cycloalkane dibasic acids are selected from C ₅ -C ₈ cycloalkyl dibasic acids, most preferably, the aliphatic dibasic acids are selected from Malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 2,3-dimethylglutaric acid, diglycolic acid, 2, 5-norbornane dicarboxylic acid, wherein the cycloalkane dibasic acid is selected from 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid.

Preferably, the aromatic dibasic acid is selected from C ₈ -C ₂₀ aromatic dibasic acids; more preferably, the aromatic dibasic acid is selected from C ₈ -C ₁₂ aromatic dibasic acids; more preferably , the aromatic dibasic acid is selected from C ₈ aromatic dibasic acids; most preferably, the aromatic dibasic acid is selected from terephthalic acid, isophthalic acid, phthalic acid, biphenyl dicarboxylic acid , 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid.

Preferably, the compound with amino and hydroxyl functional groups is selected from dibasic alcohols, aminoalcohols, aminothiols, dithiols or their derivatives with epoxy groups, nitrogen heterocycles or sulfur heterocycles one or more.

Preferably, the diol is selected from C ₂ to C ₃₀ straight chain or branched aliphatic diols; more preferably, the diol is selected from C ₂ to C ₁₀ straight chain or branched aliphatic diols. dihydric alcohol; most preferably, the dihydric alcohol is selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, 1,6- Hexylene glycol, 1,2-hexanediol, 1,4-cyclohexanedimethanol or 1,3-cyclohexanedimethanol.

Preferably, the polymerizable monomer (C) is selected from polyethylene glycol ether, polypropylene glycol ether or polytetrahydrofuran ether with a degree of polymerization of 2 to 2000; more preferably, the polymerizable monomer (C) is selected from 2-200 polyethylene glycol ether.

Preferably, the polymerizable monomer (C) is selected from polyester diol prepared from a C2 _{- C30} dibasic acid and a C2 _{- C30} glycol; more preferably, the polymerizable monomer ( C) One or more selected from polyester diols with a polymerization degree of 1-10000 prepared from C ₂ -C ₁₀ dibasic acids and C ₂ -C ₂₀ diols.

Second technical problem to be solved by this invention is to provide the preparation method of described novel copolyester, and this method comprises the following steps:

(1) The polymerized monomer (A) (B) (C) is subjected to an esterification reaction, a transesterification reaction or/and an epoxy group ring-opening reaction;

(2) the product of (1) is carried out polycondensation reaction;

(3) performing radiation crosslinking on the product of (2) under the action of a radiation source.

Preferably, the reactions of the steps (1) and (2) are carried out in the presence of a catalyst.

Preferably, the radiation source is cobalt-60 or cesium-137.

Preferably, the catalyst is antimony trioxide, antimony acetate, antimony ethylene glycol, tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate, zinc acetate, manganese acetate, germanium oxide, etc. one or a mixture of them.

The third technical problem to be solved by the present invention is to provide the application of the novel copolyester in the preparation of molding compounds, adhesives, paper materials and products, foaming materials, blends, film products or injection molded products .

The effect of the present invention is that the radiation source in the preparation method of the novel copolyester adopts cobalt 60 and cesium 137. The radiation radiation source can be installed in the polycondensation reaction kettle, and the polycondensation reaction is carried out during the polycondensation reaction, and the radiation crosslinking is carried out at the same time, thereby producing a new type of copolyester with uniform branch density; Radiation crosslinking of aromatic-aromatic copolyesters produces novel copolyesters with special branched structures. Because the branched structure in the copolyester prepared in the present invention is produced by radiation, other monomer impurities are not introduced, so the copolyester can be endowed with excellent melt strength and tear resistance and impact resistance. Excellent processing performance and product performance when processing plastic products, especially film products. At the same time, because the present invention can avoid excessive and uncontrollable crosslinking by controlling the irradiation amount and irradiation time on the molecular chain structure, it can be realized in the condensation polymerization reaction, and can also be prepared by irradiating after the polymerization reaction is completed. A new type of copolyester with a special structure is produced, and the preparation has the characteristics of simple and easy operation, which improves the production efficiency and reduces the production cost.

Description of drawings

Fig. 1 is PBAT infrared spectrum of the present invention;

Figure 2 is the infrared spectrum of PBAT containing carbon-carbon double bonds.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1

146 grams of 1,6-adipic acid, 166 grams of terephthalic acid, and 180 grams of 1,4-butanediol were placed in a 1000ml flask, and 0.01 grams of antimony trioxide was added as a catalyst, and the ester was carried out at 130°C to 240°C Chemical reaction, normal pressure, after esterification rate reaches 95%, carry out polycondensation reaction, polycondensation reaction is carried out under vacuum state, polycondensation reactor is placed under the irradiation of cobalt 60 radioactive source, and radiation equivalent dosage is 10～40 μ Sv/h ( 50cm), the dynamic viscosity reaches 750 poises and then discharges to obtain the target product PBAT. The obtained PBAT can be easily blown into a film with a thickness of 0.025mm on a film blowing machine. The film is transparent and has good toughness, the tensile strength is 23MPa, and the right-angle tear strength is 20N.

Example 2

Put 146 grams of 1,6-adipic acid, 16.6 grams of terephthalic acid, and 110 grams of 1,4-butanediol into a 1000ml flask, add 0.01 grams of antimony trioxide as a catalyst, and perform esterification at 130°C to 240°C Chemical reaction, normal pressure, after esterification rate reaches 98%, carry out polycondensation reaction, polycondensation reaction is carried out under vacuum state, polycondensation reactor is placed under the radiation of cesium 137 radioactive source, and radiation equivalent dose is 15～20 μ Sv/h ( 50cm), the kinematic viscosity reaches 680 poises and discharges to obtain the target product PBAT. The obtained PBAT can be blended with 50% calcium carbonate to make a special material, and then it can be easily blown into a film with a thickness of 0.02mm on a film blowing machine. The film is transparent and has good toughness. The tensile strength is 26MPa. The tear strength was 14N.

Example 3

73 grams of 1,6-adipic acid, 166 grams of terephthalic acid, 140 grams of 1,4-butanediol, placed in a 1000ml flask, adding 1 gram of catalyst triisopropyl titanate, at 130°C to 260°C Esterification reaction is carried out under normal pressure. After the esterification rate reaches 92.5%, polycondensation reaction is carried out. The polycondensation reaction is carried out in a vacuum state, and the material is discharged after reaching a certain viscosity. The synthesized aliphatic-aromatic copolyester is irradiated under a cesium 137 radioactive source, the radiation equivalent dose is 10-40μSv/h (50cm), and the kinematic viscosity reaches 600 poise before discharging to obtain the target product PBAT. The obtained PBAT has good processability and high melt strength, and can be blended with no more than 50% starch to prepare a special material for starch filling. Special materials can be used for injection molding, blown film and other processing.

Example 4

Put 146 grams of 1,6-hexanedioic acid, 166 grams of terephthalic acid, and 180 grams of ethylene glycol into a 1000ml flask, add 0.01 grams of antimony trioxide as a catalyst, and carry out esterification reaction at 130°C to 240°C, usually After the esterification rate reaches 95%, the polycondensation reaction is carried out, and the polycondensation reaction is carried out in a vacuum state, and the material is discharged after reaching a certain viscosity. Put the synthesized aliphatic-aromatic copolyester under the radiation source of cesium 137, the radiation equivalent dose is 1～60μSv/h (50cm) After reacting for 4 hours, take it out and granulate to get PBAT resin chips, which can be used for Injection molded products.

Example 5

Add 876kg of 1,6-adipic acid and 664kg of terephthalic acid into a 5m3 reactor, then add 1250kg of butanediol, heat at 60°C and stir for 30min, add 1.5kg of tetrabutyl titanate evenly dispersed 10 kg of BDO suspension, carry out esterification reaction at 160°C to 200°C, 0.03MPa pressure, after the esterification rate reaches 98%, vacuumize to below 100Pa for polycondensation reaction, polycondensation reaction is irradiated under cesium 137 radioactive source , The radiation equivalent dose is 35~60μSv/h (50cm), and the material is discharged after the dynamic viscosity reaches 650 poise. PBAT resin slices are obtained by granulation, which can be used in the preparation of plastic products such as blown film and extrusion.

Example 6

Add 800kg of 1,6-adipic anhydride and 500kg of terephthalic acid into a ^5m3 reactor, then add 1140kg of butanediol, heat at 60°C and stir for 60min, add 25kg to evenly disperse 1kg of antimony acetate and 1 kg of BDO suspension of germanium oxide is subjected to esterification reaction at 130°C to 170°C under a pressure of 0.05MPa. After the esterification rate reaches 95%, vacuumize to below 100Pa for polycondensation reaction. The polycondensation reaction is carried out under the cobalt 60 radiation source The radiation equivalent dose is 5-85μSv/h (50cm), and the material is discharged after the dynamic viscosity reaches 600 poise. PBAT resin slices are obtained by granulation, and filled with fillers such as calcium carbonate and/or starch to prepare special materials that can be used for injection molding, extrusion and other plastic products.

Example 7

122 grams of 1,4-butanedioic acid, 166 grams of terephthalic acid, 160 grams of ethylene glycol, placed in a 1000ml flask, adding 0.3 grams of antimony trioxide catalyst and 0.5 grams of manganese acetate, at 150 ° C to 180 ° C Esterification reaction, normal pressure, after the esterification rate reaches 90%, polycondensation reaction is carried out, the polycondensation reaction is irradiated under the vacuum state below 300Pa, and the radiation equivalent dose is 1-60μSv/h (50cm) under the radiation source of cesium 137 , and discharged after 4 hours of reaction. The new copolyester synthesized can be used for injection molding products.

Example 8

100 grams of 1,3-malonic acid, 250 grams of biphenyl dicarboxylic acid, 150 grams of 1,3-propanediol, put in a 1000ml flask, add 3 grams of tetraisopropyl titanate, and carry out at normal pressure from 120°C to 260°C Esterification reaction. After the esterification rate reaches 90%, polycondensation reaction is carried out. The polycondensation reaction is irradiated under a cesium 137 radioactive source with a radiation equivalent dose of 40-100 μSv/h (20cm) in a vacuum state below 100 Pa. Reaction 6 Discharge after hours. The new copolyester synthesized can be used to blow film to prepare packaging products.

Example 9

100 grams of oxalic acid, 214 grams of 1,5-naphthalene dicarboxylic acid, 280 grams of 1,4-cyclohexanedimethanol, put in a 1000ml flask, add 1.8 grams of catalyst ethylene glycol antimony, at 170°C to 240°C, 0.05 The esterification reaction is carried out under MPa pressure, and after the esterification rate reaches 90%, the polycondensation reaction is carried out. The polycondensation reaction is carried out in a vacuum state below 80Pa, under the radiation of a cesium 137 radiation source with a radiation equivalent dose of 40-100μSv/h (20cm), and the reaction is carried out after 8 small tests, and the material is discharged. Granulation to obtain a new type of copolyester. This product has good strength and rigidity, and can be used for injection molding chopsticks and other plastic products that require good rigidity.

Example 10

196 grams of 1,10-sebacic acid, 166 grams of terephthalic acid, 280 grams of 1,6-hexanediol were placed in a 1000ml flask, and 1.0 grams of catalyst tetraethyl titanate was added, and the process was carried out at 150°C to 180°C Atmospheric pressure esterification reaction, after the esterification rate reaches 95%, polycondensation reaction is carried out. The polycondensation reaction is carried out under the vacuum state below 500Pa, under the irradiation of a cesium 137 radiation source with a radiation equivalent dose of 10-30μSv/h (40cm), and the material is discharged after 4 small tests. Granulation to obtain a new type of copolyester. The product has good toughness and strength, and can be blown film to prepare packaging materials.

Fig. 2 is the PBAT infrared spectrum containing carbon-carbon double bond, at 1660cm ^-1 and 3100cm ^-1 there are obvious carbon-carbon double-bond characteristic spectrum peaks, but the PBAT of the present invention in Fig. 1 does not have this spectrum peak, so the present invention does not need to add The olefin initiator initiates crosslinking, but through the radiation in the polymerization process, the crosslinking is carried out synchronously during the copolyester polymerization process, and it is relatively easy to obtain a new type of copolyester with uniform crosslinking and controllable crosslinking density. Simple and the product performs well.

Claims (26)

1. A copolyester, the polymerization monomer of this copolyester comprises: (A) one or more compounds in aliphatic dibasic acids, naphthenic dibasic acids or their esters and acid anhydrides; (B) one or more of aromatic dibasic acids or their esters and anhydrides; (C) Compounds with hydroxyl functional groups, or one or more compounds in their derivatives with epoxy groups, nitrogen heterocycles or sulfur heterocycles; It is characterized in that: the novel copolyester is prepared by mixing the above polymerized monomers through esterification reaction, polycondensation reaction and radiation crosslinking reaction in the polycondensation process. 2 . The copolyester according to claim 1 , characterized in that: the molar ratio of hydroxyl groups to carboxyl groups in the polymerized monomers is 0.8˜5:1. 3. The copolyester according to claim 1, characterized in that: the molar ratio of the polymerized monomers (A), (B) and (C) is 10-95:5-95:0.0001-10 . 4. The copolyester according to claim 1, characterized in that the number average molecular weight of the copolyester is 10,000-300,000, and the molecular weight distribution is 1.2-6.5. 5. The copolyester according to claim 1, characterized in that: the melting point of the novel copolyester is 30-210°C, and the glass transition temperature is -60-100°C. 6. The copolyester according to claim 1, characterized in that: the aliphatic dibasic acid is selected from C ₂ -C ₃₀ aliphatic dibasic acids, and the naphthenic dibasic acid is selected from C ₅ -C 30 aliphatic dibasic acids. C ₂₀ naphthenic dibasic acid. 7. The copolyester according to claim 1, characterized in that: the aliphatic dibasic acid is selected from C ₂ -C ₁₀ aliphatic dibasic acids, and the naphthenic dibasic acid is selected from C ₅ -C 10 aliphatic dibasic acids. C ₁₀ cycloalkyl dibasic acid. 8. The copolyester according to claim 1, characterized in that: the aliphatic dibasic acid is selected from C ₂ -C ₆ aliphatic dibasic acids, and the naphthenic dibasic acid is selected from C ₅ -C 6 aliphatic dibasic acids. C ₈ cycloalkyl dibasic acid. 9. copolyester according to claim 1 is characterized in that: described aliphatic dibasic acid is selected from malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, Azelaic acid, sebacic acid, 2,3-dimethylglutaric acid, diglycolic acid, 2,5-norbornane dicarboxylic acid, the naphthenic dibasic acid selected from 1,3-cyclo Adipic acid, 1,4-cyclohexanedioic acid. 10 . The copolyester according to claim 1 , wherein the aromatic dibasic acid is selected from C ₈ -C ₂₀ aromatic dibasic acids. 11 . 11. The copolyester according to claim 1, characterized in that: the aromatic dibasic acid is selected from C ₈ -C ₁₂ aromatic dibasic acids. 12. The copolyester according to claim ₁ , characterized in that: the aromatic dibasic acid is selected from C8 aromatic dibasic acid. 13. The copolyester according to claim 1, characterized in that: the aromatic dibasic acid is selected from the group consisting of terephthalic acid, isophthalic acid, phthalic acid, diphthalic acid, 2,6- Naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid. 14. The copolyester according to claim 1, characterized in that: the compound with hydroxyl functional group is selected from dibasic alcohol or its derivatives with epoxy group, nitrogen heterocycle or sulfur heterocycle one or more of . 15 . The copolyester according to claim 14 , wherein the diol is selected from C ₂ -C ₃₀ linear or branched aliphatic diols. 16 . The copolyester according to claim 14 , wherein the diol is selected from C ₂ -C ₁₀ straight chain or branched aliphatic diols. 17. The copolyester according to claim 14, characterized in that: said glycol is selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1, 2-Butanediol, 1,6-hexanediol, 1,2-hexanediol, 1,4-cyclohexanedimethanol or 1,3-cyclohexanedimethanol. 18. The copolyester according to claim 1, characterized in that: the polymerizable monomer (C) is selected from polyethylene glycol ether, polypropylene glycol ether or polytetrahydrofuran ether with a degree of polymerization of 2-2000. 19. The copolyester according to claim 1, characterized in that: the polymerizable monomer (C) is selected from polyethylene glycol ethers with a polymerization degree of 2-200. 20. The copolyester according to claim 1, characterized in that: the polymerizable monomer (C) is selected from polyesters prepared from dibasic acids of C ₂ to C ₃₀ and glycols of C ₂ to C ₃₀ glycol. 21. The copolyester according to claim 1, characterized in that: the polymerizable monomer (C) is selected from the degree of polymerization prepared from dibasic acids of C ₂ to C ₁₀ and dibasic alcohols of C ₂ to C ₂₀ One or more of 1-10000 polyester diols. 22. The method for preparing the copolyester described in any one of claims 1 to 21, is characterized in that, comprises the following steps: (1) The polymerized monomer (A) (B) (C) is subjected to an esterification reaction, a transesterification reaction or/and an epoxy group ring-opening reaction; (2) the product of (1) is carried out polycondensation reaction; (3) performing radiation crosslinking on the product of (2) under the action of a radiation source. 23. The preparation method of the copolyester according to claim 22, characterized in that: the reactions of the steps (1) and (2) are carried out in the presence of a catalyst. 24. The method for preparing the copolyester according to claim 22 or 23, characterized in that the radiation source is cobalt-60 or cesium-137. 25. according to the preparation method of described copolyester in claim 23, it is characterized in that described catalyzer is antimony trioxide, antimony acetate, ethylene glycol antimony, tetraethyl titanate, tetraisopropyl titanate , tetrabutyl titanate, zinc acetate, manganese acetate, germanium oxide and other substances or a mixture of two or more. 26. The application of the copolyester according to any one of claims 1 to 21 in the preparation of molding compounds, adhesives, paper materials and products, foam materials, blends, film products or injection molded products.