How much do you know about ABS plastic? How to improve its heat resistance and the 8 major requirements that must be met

The aBS resin is a graft copolymer of three monomers of acrylonitrile, butyl butadiene, and styrene. Its molecular formula can be written as (C8H8?C4H6?C3H3N)x, but in practice it is often a mixture of a butadiene-containing graft copolymer and an acrylonitrile-styrene copolymer.

Among them, acrylonitrile accounts for 15%~35%, butadiene accounts for 5%~30%, styrene accounts for 40%~60%, plastic aBS has heat distortion temperature of 93~118°C, and products can be improved after annealing. °C or so. aBS can still exhibit a certain toughness at -40 ° C, and can be used in the temperature range of -40 to 100 ° C. However, in some cases, the ambient temperature will be higher than 100 ° C. Therefore, in order to make the material meet the requirements of use, it is generally only to improve the heat resistance of aBS, thereby broadening its non-application field.

First, why should we improve the heat resistance of aBS plastic?

aBS has good processability and good toughness, but its heat resistance is not enough, which limits its application range. In general, the aBS Vicat softening point is around 95 ° C, and the heat resistant aBS (VST/B/50) exceeds 100 ° C. Therefore, it is necessary to increase the heat resistance of aBS to expand its application.

Especially in the automotive and electronic and electrical aspects, for automotive interior parts dashboards, toolboxes, ashtrays, new extrusion and other components; automotive exterior components, such as front grille, car base, painted mirror door panel components, wheels The hood, the spoiler, the gearbox cover, etc. all require good heat resistance.

In addition, in the electrical and electronic aspects, vacuum cleaner housings, microwave oven door frames, hair dryers, etc. also require aBS material to have better heat resistance, in order to meet the material requirements of the parts, the specific requirements are as follows: in high temperature environment, with a high degree stability

High impact resistance

Excellent dimensional stability

Easy to process

Unbeatable surface

Low VOC

Second, how to improve the heat resistance of aBS plastic?

The heat resistance of plastics is generally defined as the measure of how many characteristics are maintained below ambient temperature in high temperature environments. In general, high-molecular materials change the physical properties of materials because of the increased molecular motion, and the most obvious is elasticity. The most common way to improve the heat resistance of polymer materials is to inhibit molecular motion. Generally, the following methods are available: 1. The molecular model of the polymer is framed into a three-dimensional structure to form a mesh to suppress molecular motion; 2. A difficult-to-operate aromatic ring and an alicyclic structure are added to the molecular mechanism; 3. In the polymer The polar group is added to the inside, thereby relying on the binding force of the hydrogen-oxygen chain to suppress the molecular structure; 4. Introducing the crystal structure into the polymer structure for heat-resistant modification, using a heat-resistant modifier.

In general, aBS heat resistance can be improved by lowering the rubber content, increasing the SaN molecular weight and the acrylonitrile content, but the method of developing heat resistance and aBS by adding a heat resistant monomer or a heat resistant additive has attracted more attention. Therefore, many well-known aBS plastics modification companies mostly use heat-resistant modifiers to improve the heat resistance of aBS.

Third, a good heat-resistant modifier should meet these 8 major requirements!

At present, in addition to improving the heat resistance of aBS plastics, the problem of automotive VOCs has become more and more important; people hope that the lower the volatile organic solvents in heat-resistant aBS plastics, the better. Therefore, the requirements for heat-resistant modifying auxiliaries have not only stayed in the demand for improving heat resistance, but also have requirements for reducing VOC. Therefore, in the future, the heat-resistant modification additives required by the modified plastics enterprises need to meet the following requirements:

High heat resistance (glass transition temperature = 175 ° C)

Better thermal stability

Good dimensional stability

Very easy to mix with aBS and SaN

Improve product surface adhesion

High liquidity

Good processing performance

Low VOC