Comparative analysis of eight common plastic modification techniques
1) fiber reinforcement
Long fiber reinforced thermoplastics (UCRT) is a new kind of lightweight and high strength engineering structure material. Body parts made of natural fibers such as flax and sisal reinforced plastics have been recognized in the automotive industry. On the one hand, natural fiber is environmentally friendly material, on the other hand, plant fiber is 40% lighter than glass fiber, reducing the weight of the car can reduce the oil consumption. Linen-reinforced PP is used to make body bottom plate. The tensile strength of the material is higher than that of steel, and the rigidity of the material is not lower than that of fiberglass reinforced material. The parts are easier to recycle. The drive shaft made of fiber-reinforced plastic by GKN technology is 50% to 60% lighter, 1.0 times more torsional than steel and 1.5 times more flexural. Plastic springs can significantly reduce weight. The plate spring made of carbon fiber reinforced plastic (CFRP) is 14kg, reducing the weight by 76%. In the United States, Japan, Europe have used plate spring, cylindrical coil spring to achieve fiber reinforced plastic, in addition to the obvious effect of vibration and noise reduction, but also to achieve the purpose of lightweight.
(2) toughening technology
The stiffness (including strength) and toughness of polymer structural materials are the two most important performance indexes that restrict each other. Therefore, the study of enhancing stiffness and toughening has always been a difficult problem in polymer materials science. Chinese academy of sciences institute of chemistry of polymer blend filled with a new way of enhanced toughening, which results in solving the high polymer material at the same time strengthening toughening of scientific problem for important breakthrough, the ultra high toughness successfully prepared for the first time in domestic polyolefin engineering plastics, general plastic upgrade for great variety, for further high-performance engineering plastics and engineering plastics provides a new way. The super gravity engineering technology research center of the Ministry of Education has successfully developed the national "863" project -- "nano-caco3 plastic toughening masterbatch and its preparation technology". This material can toughen and modify PVC, mainly used in PVC doors and Windows profile production, but also used in PVC pipe, plate and other hard products production. Look from development trend, door window of PVC plastic has the potential that replaces steel window and woodiness door window completely greatly. At present, the annual production capacity of domestic PVC doors and Windows profile is 1 million t, and shows a rising trend. Adopting nano CaCO3 plastic toughening masterbatch to produce PVC doors and Windows profile can not only comprehensively improve the product performance, but also reduce the cost of profile per ton by more than 100 yuan. At the same time, its application will be PP, ABS and other plastic materials in the expansion. Toughening PVC with nano CaCO3 is a non-elastomeric toughening plastic technology (inorganic rigid particle toughening plastic technology) developed in recent years, which is still in the research stage in China. Two major problems will occur when nano CaCO3 is added directly. First, nano particles will coalescence in the plastic matrix, resulting in uneven dispersion, which affects the toughening effect. Second, nano CaCO3 particles are small, which is easy to produce dust and affect the environment. The successful development of nano-caco3 plastic toughening masterbatch and its preparation technology has effectively solved the two major problems in the same research field at home and abroad.