Инженерните пластмаси се отнасят главно до термопластици, които могат да се използват като структурни материали. Engineering plastics have excellent comprehensive properties, high rigidity, low creep, high mechanical strength, good heat resistance, and good electrical insulation. They can be used for a long time in harsh chemical and physical environments and can replace metals as engineering structural materials. Engineering plastics can be divided into general engineering plastics and special engineering plastics. The main varieties of the former are polyamide (PA), polycarbonate (PC), polyoxymethylene (POM), polyphenylene ether (PPO) and polyester (PBT). And PET) five general engineering plastics; the latter usually refers to engineering plastics with heat resistance above 150Co, the main varieties are polyphenylene sulfide (PPS), liquid crystal High molecular polymer (LCP), polysulfone (PSF), polyimide (PI), polyaryletherketone (PEEK), polyarylate (PAR), etc.
There is no clear dividing line between engineering plastics and general-purpose plastics. For example, acrylonitrile-butadiene-styrene copolymer (ABS) lies between the two. Its advanced grades can be used as engineering structural materials. The grade is ordinary general-purpose plastics (abroad generally speaking, ABS is classified as general-purpose plastics). For another example, polypropylene (PP) is a typical general-purpose plastic, but after glass fiber reinforcement and other blending, its mechanical strength and heat resistance have been greatly improved, and it can also be used as a structural material in many engineering fields . For another example, polyethylene is also a typical general-purpose plastic, but ultra-high molecular weight polyethylene with a molecular weight of more than 1 million, due to its excellent mechanical properties and high heat distortion temperature, can be widely used as engineering plastics in machinery, transportation, Chemical equipment etc.
In the past few decades, people have been committed to the development of new polymer materials. Сред хилядите новоразработени полимерни материали малцина имат широкомащабни приложения. Therefore, we cannot hope to develop new ones. Polymer materials to improve performance. However, it has become a natural choice to process plastics by filling, blending, and reinforcing methods to enhance their flame retardancy, strength, and impact resistance.
Ordinary plastics have shortcomings such as flammability, aging, low mechanical properties, and low operating temperature in industrial use and daily consumption. Through modification, ordinary plastics can achieve performance enhancement, function increase, and cost reduction. The upstream of the modified plastic is the primary form resin, which uses additives or other resins that improve the performance of the resin in one or several aspects such as mechanics, rheology, combustibility, electricity, heat, light, and magnetism as auxiliary materials. , Закаляване, укрепване, смесване, легиране и други технически средства за получаване на материали с еднакъв вид.
Пет пластмаси с общо предназначение като базови материали: полиетилен (PE), полипропилен (PP) и поливинил хлорид