CN103756272B - High-performance TLCP fiber reinforcement PBT composite and its preparation method - Google Patents

Abstract

The invention discloses a high-performance TLCP fiber-reinforced PBT composite material, which is composed of the following raw materials: PBT resin, polyarylate TLCP fiber, antioxidant, lubricant, anti-UV agent and anti-hydrolysis agent. A method for preparing a high-performance TLCP fiber reinforced PBT composite material, comprising the following steps: 1) fully drying the raw materials; 2) mixing and stirring the raw materials except polyarylate TLCP fibers; 3) mixing the raw materials in step 2) The uniformly mixed raw materials are fed into the extruder through the main feeding port, and the polyarylate TLCP fiber is fed into the extrusion through the side feeding port, and then melted and extruded, drawn, cooled, and pelletized. The PBT composite material of the invention has excellent mechanical properties, high tensile strength, flexural strength, flexural modulus, notched impact strength, good appearance, excellent resistance to heat and oxygen degradation, and good hydrolysis resistance. In addition, the preparation process of the invention is simple and the cost is low.

Description

High performance TLCP fiber reinforced PBT composite material and its preparation method

technical field

The invention relates to a high-performance TLCP fiber reinforced PBT composite material and a preparation method thereof.

Background technique

Polybutylene terephthalate (PBT) is a thermoplastic saturated polyester engineering plastic with a fast crystallization rate (main varieties are PBT, PET and PTT). It has excellent comprehensive properties and is easy to achieve high-speed molding. It is widely used In the automobile, electronic and electrical manufacturing industries, it is used to manufacture parts with high mechanical strength and heat-resistant, friction-resistant, high-insulation parts, etc. It is one of the five general-purpose engineering plastics. With the development of modification technology, glass fiber reinforcement and mineral filling have effectively improved the shortcomings of PBT's large shrinkage rate and greatly increased its scope of application. However, traditional reinforced modified PBT resins still have poor mechanical strength (compared to other crystalline engineering plastics and high-performance engineering plastics), sensitivity to gaps, and large specificity (about 1.30, second only to POM in general engineering plastics) 2) The appearance of large-scale parts is not ideal, and the hydrolysis resistance is poor. It is necessary to further modify the PBT material to meet the wider needs of people.

TLCP (Thermotropic Liquid Crystal Polymer) is the abbreviation of thermotropic liquid crystal polymer material. Thermotropic liquid crystal polymer materials have all the excellent characteristics of ordinary liquid crystal polymers. At the same time, because their melting temperature is lower than the decomposition temperature, high-performance fibers can be prepared by melt spinning. In comparison, it is a high-tech material with great application potential due to its wide variety, mature synthesis process, good processability and low cost. Polyarylate-type TLCP can be prepared into a high-tech fiber with excellent comprehensive properties such as high strength and high modulus, high temperature resistance, self-flame retardancy, chemical resistance, radiation resistance, and strong dimensional stability through melt spinning. Its strength It exceeds 18cN/dtex, which meets the standard of special fibers. The comprehensive mechanical properties are slightly higher than that of aramid fibers, and it has excellent dimensional stability, basically no water absorption, good UV resistance and weather resistance. In addition, compared with the current three traditional high-performance fibers (aramid, ultra-high molecular weight polyethylene, carbon fiber), it is the only high-performance fiber prepared by melt spinning method, which has lower cost, less pollution, and the The fiber does not need post-stretching and other processes, but only needs to be heat-treated to further improve its modulus, strength and service temperature.

However, TLCP fibers are used to enhance and comprehensively modify PBT, such as improving its mechanical properties such as flexural strength, flexural modulus, tensile strength, etc., while taking into account density, heat and oxygen aging resistance, appearance, and hydrolysis resistance. The optimization is an urgent problem to be solved.

Contents of the invention

The object of the present invention is to provide a kind of high-performance TLCP fiber reinforced PBT composite material and preparation method thereof.

The technical scheme that the present invention takes is:

A high-performance TLCP fiber reinforced PBT composite material, which is composed of the following raw materials in mass percentage: PBT resin 64.4-79.8%, polyarylate TLCP fiber 18-23%, antioxidant 0.5-3%, lubricant 0.5% ~4%, anti-UV agent 0.4-1.6%, anti-hydrolysis agent 0.8-4%.

The monofilament diameter of the polyarylate TLCP fiber is 20-50 μm, the chopped length is 0.4-4.0 mm, and the specific gravity is 1.41-1.55 g/cm ³ .

The antioxidants include hindered phenolic antioxidants and phosphite antioxidants.

The antioxidant is at least one of antioxidants 1010, 168, 1076, 1098, 245, DHT246, composite B215, composite B225, DLTP, DSTP, and 412S.

Described lubricant is oleamide, stearamide, stearic acid, magnesium stearate, calcium stearate, microcrystalline paraffin, erucamide, epoxy soybean oil, PETS, EBS, TAF, montan wax, at least one of silicones.

The anti-UV agent is at least one of UV-9, UV-234, UV-531, UV-327, UV-328, UV-329, UV-1130, and UV-770.

The anti-hydrolysis agent is carbodiimide or polycarbodiimide.

A kind of preparation method of high-performance TLCP fiber reinforced PBT composite material, comprises the following steps:

1) fully drying the PBT resin and the polyarylate TLCP fiber until its water content is lower than 0.02%;

2) Mix and stir the raw materials except the polyarylate TLCP fiber evenly;

3) Add the homogeneously mixed raw materials in step 2) into the extruder through the main feeding port, and pass the polyarylate TLCP fiber through

It is fed into the extrusion through the side feeding port, and then melted and extruded, drawn, cooled, and pelletized.

The temperature of melt extrusion is 220-260°C.

The beneficial effect of the present invention is: the mechanical performance of the PBT composite material of the present invention is excellent, has higher tensile strength, flexural strength, flexural modulus, notched impact strength, and appearance is better, heat-resistant oxygen degradation is excellent, also has relatively Good hydrolysis resistance. In addition, the preparation process of the invention is simple and the cost is low.

detailed description

A high-performance TLCP fiber reinforced PBT composite material, which is composed of the following raw materials in mass percentage: PBT resin 64.4-79.8%, polyarylate TLCP fiber 18-23%, antioxidant 0.5-3%, lubricant 0.5% ~4%, anti-UV agent 0.4-1.6%, anti-hydrolysis agent 0.8-4%.

Preferably, a high-performance TLCP fiber reinforced PBT composite material is composed of the following raw materials in mass percentage: PBT resin 72.7-77.7%, polyarylate TLCP fiber 18-23%, antioxidant 0.8-1%, Lubricant 0.6-1%, anti-UV agent 0.4-0.8%, anti-hydrolysis agent 1.5-2.5%.

The monofilament diameter of the polyarylate TLCP fiber is 20-50 μm, the chopped length is 0.4-4.0 mm, and the specific gravity is 1.41-1.55 g/cm ³ . It is derived from the Ekonol series of Sumitomo of Japan, the Rodrun-LC series of Unitika of Japan, the Vectran series of Polyplastics of Japan, the Vectra series of Hoeshst Celanese of the United States, the DuPont ( DuPont's Zenite series, American Amoco's Xydar series or German BASF's Ultrax series.

The antioxidants include hindered phenolic antioxidants and phosphite antioxidants. Preferably, the antioxidant is at least one of antioxidants 1010, 168, 1076, 1098, 245, DHT246, composite B215, composite B225, DLTP, DSTP, and 412S.

Described lubricant is oleamide, stearamide, stearic acid, magnesium stearate, calcium stearate, microcrystalline paraffin, erucamide, epoxy soybean oil, PETS, EBS, TAF, montan wax, at least one of silicones.

The anti-UV agent is at least one of UV-9, UV-234, UV-531, UV-327, UV-328, UV-329, UV-1130, and UV-770.

The anti-hydrolysis agent is carbodiimide or polycarbodiimide.

A kind of preparation method of high-performance TLCP fiber reinforced PBT composite material, comprises the following steps:

1) fully drying the PBT resin and the polyarylate TLCP fiber until its water content is lower than 0.02%;

2) Mix and stir the raw materials except the polyarylate TLCP fiber evenly;

3) Add the homogeneously mixed raw materials in step 2) into the extruder through the main feeding port, and pass the polyarylate TLCP fiber through

It is fed into the extrusion through the side feeding port, and then melted and extruded, drawn, cooled, and pelletized.

The temperature of melt extrusion is 220-260°C.

Below in conjunction with specific embodiment, formula of the present invention is described further:

Example 1:

A kind of high-performance TLCP fiber reinforced PBT composite material, its formula composition is as follows:

Table 1

Example 2:

A kind of high-performance TLCP fiber reinforced PBT composite material, its formula composition is as follows:

Table 2

Example 3:

A kind of high-performance TLCP fiber reinforced PBT composite material, its formula composition is as follows:

table 3

Example 4:

A kind of high-performance TLCP fiber reinforced PBT composite material, its formula composition is as follows:

Table 4

The formulation system of embodiment 1-4 is made into corresponding test piece, tests, and its result is as follows:

table 5

PBT material of the present invention is compared with other materials, and the results are as follows:

Table 6

The hydrolysis resistance test is carried out as follows: the test piece is placed in a mixed solvent of water and ethylene glycol (the volume ratio of water and ethylene glycol is 1:1), and the temperature is raised to 125 ° C for 15 days to hydrolyze. The retention rate of the tensile strength of the sample with respect to the pre-hydrolysis was rated as good at 50% or more, and poor at 30% or less.

The T _g of the polyarylate TLCP used in the present invention is <220°C, and the T _m is >260°C. Type TLCP fibers are in a state between their _Tg and _Tm temperatures;

And it has a structure similar to thermoplastic saturated linear polyester material, so it has good compatibility with PBT matrix;

The monofilament diameter of the polyarylate TLCP fiber is 20-50 μm, the chopped length is 0.4-4.0 mm, the specific gravity is 1.41-1.55 g/cm ³ , and the long-diameter ratio is high.

The composite material prepared by the invention has the following characteristics: low specific gravity, super high strength, easy coloring, easy molding and excellent appearance.

Claims (5)

1. A kind of high-performance TLCP fiber reinforced PBT composite material is characterized in that: it is made up of the raw material of following mass percent: PBT resin 64.4～79.8%, polyarylate type TLCP fiber 18～23%, antioxidant 0.5～ 3%, lubricant 0.5~4%, anti-UV agent 0.4~1.6%, anti-hydrolysis agent 0.8~4%; the monofilament diameter and chopped length of the polyarylate TLCP fiber are one of the following groups Group: diameter 25μm, chopped length 1.5mm; diameter: 25μm, chopped length 2.0mm; diameter: 25μm, chopped length 3.0mm; specific gravity 1.41~1.55g/cm3; the antioxidant is antioxidant 1010 , 168, 1076, 1098, 245, DHT246, compound B215, compound B225, DLTP, DSTP, at least one of 412S; the anti-UV agent is UV-9, UV-234, UV-531, UV-327 , UV-328, UV-329, UV-1130, UV-770 at least one. 2. A kind of high performance TLCP fiber reinforced PBT composite material according to claim 1, is characterized in that: described lubricant is oleamide, stearylamide, stearic acid, magnesium stearate, calcium stearate , microcrystalline paraffin, erucamide, epoxidized soybean oil, PETS, EBS, TAF, montan wax, silicone at least one. 3. A high-performance TLCP fiber-reinforced PBT composite material according to claim 1, characterized in that: the anti-hydrolysis agent is carbodiimide or polycarbodiimide. 4. the preparation method of a kind of high-performance TLCP fiber reinforced PBT composite material described in claim 1, is characterized in that: comprise the following steps: 1) Fully dry the PBT resin and polyarylate TLCP fiber until its water content is lower than 0.02%; 2) Mix and stir the raw materials except polyarylate TLCP fiber; 3) Add the uniformly mixed raw materials in step 2) into the extruder through the main feeding port, feed the polyarylate TLCP fiber into the extrusion through the side feeding port, and carry out melt extrusion, traction, cooling, cutting grains. 5. A method for preparing a high-performance TLCP fiber-reinforced PBT composite material according to claim 4, characterized in that: the temperature of melt extrusion is 220-260°C.