CN112592583B

CN112592583B - Alcoholysis-resistant enhanced PA6T material and preparation method thereof

Info

Publication number: CN112592583B
Application number: CN202011278992.6A
Authority: CN
Inventors: 全敦华; 杨杰; 陈明进; 刁雪峰; 申应军; 吴腾达
Original assignee: Jinyoung Xiamen Advanced Materials Technology Co Ltd
Current assignee: Jinyoung Xiamen Advanced Materials Technology Co Ltd
Priority date: 2020-11-16
Filing date: 2020-11-16
Publication date: 2023-03-10
Anticipated expiration: 2040-11-16
Also published as: CN112592583A

Abstract

The invention discloses an alcoholysis-resistant reinforced PA6T material and a preparation method thereof, wherein the material comprises, by mass, 38.4-64.4 parts of high-temperature nylon, 30-50 parts of reinforced fibers, 5-10 parts of a compatilizer, 0.2-0.5 part of a heat stabilizer, 0.2-0.5 part of an antioxidant and 0.2-0.6 part of a lubricant, wherein the compatilizer is a styrene-N-phenylmaleimide copolymer, can capture alcohol substances invading the material, plays a role in active defense, improves the binding force between glass and matrix resin, and enables the material to have good alcoholysis resistance. The preparation method is simple and has strong industrial practicability.

Description

Alcoholysis-resistant enhanced PA6T material and preparation method thereof

Technical Field

The invention belongs to the technical field of plastic materials for engines, and particularly relates to an alcoholysis resistance enhanced PA6T material and a preparation method thereof.

Background

The cooling system is an important component of the engine system and its function is to ensure that the engine operates in the proper temperature range. At present, a water-cooling system is generally adopted, and cooling liquid is driven by a water pump and takes away redundant heat of an engine through parts such as the water pump, an engine cooling water jacket, a radiator, a thermostat, a cold air system connecting pipeline and the like. The main plastic parts of the cooling system comprise a water tank, a radiator water chamber, a thermostat shell, a water pump impeller and a throttle valve, and the plastic parts are in long-term contact with cooling liquid in the use process and require good performance of resisting the cooling liquid. The main components of the refrigerating fluid are 1. At present, a PA66+30% glass fiber is mainly adopted by a cooling system, along with the improvement of the heat efficiency of an engine, the working temperature of the engine is higher and higher, the efficiency requirement of the cooling system is severer day by day, the vitrification temperature of the PA66 is low at high temperature, the material strength is insufficient, the material is easy to corrode by ethylene glycol, and the requirement of future automobile products cannot be met. PA6T has very high glass transition temperature and melting point and can well meet the requirements of cooling system materials, but PA6T also has very high amido bond density, researches show that the tensile strength retention rate of PA6T is only 35% after soaking in ethanol at 23 ℃ for 168h, and various automobile manufacturers generally require that the tensile strength retention rate is more than 40% or more than 40MPa after soaking in refrigerating fluid at a temperature of 1000h and above 130 ℃. In the prior art, a polyamine hydrolysis resistant agent is generally added to react with a nylon terminal carboxyl group, a metal halide and an amide group are added to form a complex structure to stabilize a nylon molecular chain, a coupling agent and an ethylene-octene copolymer grafted maleic acid rod POE-G-MAH are added to improve the adhesive force between glass fiber and matrix resin and use special hydrolysis resistant glass fiber, but the polyamine and the metal halide are expensive, glycol invading the material is not actively captured, the coupling agent is not temperature-resistant, the coupling agent is easy to lose efficacy at high temperature and cannot effectively couple, and the PEO-G-MAH can reduce the glass transition temperature of the material.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides an alcoholysis resistance enhanced PA6T material and a preparation method thereof, and solves the problem of alcoholysis resistance of the plastic parts of the engine in the background art.

One of the technical schemes adopted by the invention for solving the technical problems is as follows: provides an alcoholysis-resistant reinforced PA6T material which comprises the following components in parts by mass:

wherein the high-temperature nylon is at least one of poly (hexamethylene terephthalate), an isophthalic acid hexamethylene diamine copolymer, poly (hexamethylene terephthalate) and a 2-methyl-1, 5-pentanediamine copolymer; the compatilizer is a styrene-N-phenylmaleimide copolymer, and the reinforcing fiber is hydrolysis-resistant glass fiber.

In a preferred embodiment of the present invention, the compatibilizer has the formula

Wherein the NPMI content is 30-35wt%, the Sty content is 55-68wt%, the MAH content is 2-10wt%, and the molecular weight is 2 x 10^ ⁴ -3*10^ ⁴ In between.

In a preferred embodiment of the present invention, the glass transition temperature of the compatibilizer is 196 ℃ and the thermal decomposition temperature is 350 ℃.

In a preferred embodiment of the invention, the high-temperature nylon is nylon with the characteristic viscosity of 0.6-1.0 dL/g.

In a preferred embodiment of the invention, the surface of the reinforcing fiber at least contains 0.5wt% of maleic stem grafted or copolymerized polyolefin fiber emulsifier.

In a preferred embodiment of the invention, the diameter of the reinforcing fiber is 11-12 μm, and the chopped length is 3-4.5mm.

In a preferred embodiment of the present invention, the thermal stabilizer is bis (2, 6-tetramethyl-3-piperidinylamino) -isophthalamide (SEED).

In a preferred embodiment of the invention, the antioxidant is 3, 9-bis (2, 4-dicumylphenoxy) -2,4,8, 10-tetraoxa-3, 9-diphosphaspiro [5.5] undecane (9228).

In a preferred embodiment of the present invention, the lubricant is one or more of a modified high molecular weight silicone lubricant and an ethylene acrylic acid copolymer.

The second technical scheme adopted by the invention for solving the technical problems is as follows: the preparation method of the alcoholysis resistance enhanced PA6T material comprises the following steps:

1) Uniformly mixing the high-temperature nylon, the compatilizer, the heat stabilizer, the antioxidant and the lubricant in parts by mass to obtain a premix;

2) Adding the premix into a double-screw extruder, and adding the reinforced fibers from the side according to the mass parts, wherein the double-screw extruder adopts a medium-strength screw, and the length-diameter ratio is 40-44: 1, extruding at 280-320 ℃ and at a rotating speed of 350-500r/min to obtain the alcoholysis resistance enhanced PA6T material.

Compared with the background technology, the technical scheme has the following advantages:

the invention adopts PA6T/6I and PA6T/DT with high glass transition temperature to cooperate with styrene-N-phenylmaleimide copolymer with high glass transition temperature, high temperature resistance and high maleic anhydride content, utilizes phenylmaleimide and maleic anhydride in the styrene-N-phenylmaleimide copolymer to capture alcohol substances in the invasive material, compared with the prior art, plays the role of active defense, and can also improve the cohesive force between glass and matrix resin; meanwhile, the styrene-N-phenylmaleimide copolymer has the decomposition temperature of 350 ℃ suitable for high-temperature processing, is matched with the processing temperature of high-temperature nylon, and has good industrial practicability.

Detailed Description

In the preparation process of the following examples or comparative examples, the high-temperature nylon, the compatilizer, the heat stabilizer, the antioxidant and the lubricant are weighed according to the following table 1 and uniformly mixed in a low-speed mixer; and then, adding the premix into a double-screw extruder, adding the reinforced fibers from a side feed according to the mass ratio, wherein the double-screw extruder with a medium-strength screw is adopted, and the length-diameter ratio is 40-44: 1, extruding at 280-320 ℃ and rotating speed of 350-500r/min; wherein, the diameter of the reinforced fiber is 11 microns, the chopped length is 3-4.5mm, and the reinforced fiber is quantitatively fed from a 5 th cylinder by a weight loss metering device.

TABLE 1 ingredient tables for examples 1 to 3 and comparative examples 1 to 3

The nylon materials prepared in the above examples 1 to 3 and comparative examples 1 to 3 were tested, and the results are shown in the following table 2:

TABLE 2 results of Performance test of examples 1 to 3 and comparative examples 1 to 3

Compared with the comparative example 1, the embodiment 1 shows that the alcoholysis resistance of the material can be obviously improved by adding the styrene-N-phenylmaleimide copolymer, the styrene-N-phenylmaleimide copolymer has high decomposition temperature and is suitable for high-temperature processing, the styrene-N-phenylmaleimide copolymer contains a large amount of anhydride functional groups, the bonding force between glass fibers and matrix resin can be improved, meanwhile, unreacted anhydride functional groups can react with invaded glycol to generate esters, the esters play a role of alcohol capture agents, the glass transition temperature is high, molecular chain segments are still in a frozen state at 130 ℃, and the glycol is not easy to enter the material; compared with the comparative example 2, the effect of adding the styrene-N-phenylmaleimide copolymer is obviously better than that of adding the POE-G-MAH, on one hand, the anhydride content of the POE-G-MAH is low, and the grafting rate is only 0.5-1.5 percent, and on the other hand, the addition of the POE-G-MAH reduces the glass transition temperature of the material, so that the alcoholysis resistance of the material at high temperature is greatly reduced; comparison of example 1 with comparative example 3 shows that PA6T/6I has a glass transition temperature of greater than 135 ℃ and significantly higher than the glass transition temperature of PA66 at about 65 ℃, although the crystallinity is lower than PA66, the alcoholysis resistance is significantly better than PA66, particularly at high temperatures.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. Use of an alcoholysis-resistant reinforced PA6T material for the production of plastic parts for engines, characterized in that: the composition comprises the following components in parts by weight:

51.1 parts of high-temperature nylon

40 portions of reinforcing fiber

8 portions of compatilizer

0.3 part of heat stabilizer seed

9228.3 portions of antioxidant

0.3 part of lubricant AC 540A;

wherein the high-temperature nylon is PA6T/6I, the glass transition temperature of the PA6T/6I is more than 135 ℃, and the intrinsic viscosity is 0.6-1.0dL/g;

the compatilizer is a styrene-N-phenylmaleimide copolymer and is used for actively capturing alcohol substances in the invasive material; the molecular formula of the compatilizer is

Wherein the NPMI content is 30-35wt%, the Sty content is 55-68wt%, the MAH content is 2-10wt%, and the molecular weight is 2 x 10^ ⁴ -3*10^ ⁴ To (c) to (d); the glass transition temperature of the compatilizer is 196 ℃, and the thermal decomposition temperature is 350 ℃;

the reinforced fiber is hydrolysis-resistant glass fiber, and the surface of the reinforced fiber at least contains 0.5wt% of maleic anhydride grafted or copolymerized polyolefin fiber emulsifier; the diameter of the reinforced fiber is 11 μm, and the chopped length is 3-4.5mm;

the preparation method of the alcoholysis-resistant reinforced PA6T material comprises the following steps:

1) Uniformly mixing high-temperature nylon, a compatilizer, a heat stabilizer, an antioxidant and a lubricant in parts by mass to obtain a premix;