Understanding PET modification methods in one article
1, PET filler modification
Filling modification is the use of inorganic components that are completely different from the polymer matrix to enhance the overall performance of the material in one of the most direct and effective way.
2、Nanoparticle modification of PET
At present, the use of nanoparticles to modify PET composites research has been very mature. ke et al. with laminated clay to modify PET, using the method of insertion polymerization to obtain PET / clay nanocomposites. The results of the study show that when the clay content of 5wt%, the heat distortion temperature of the composite material than pure PET increased by about 20 ℃ ~ 50 ℃; and the modulus of the composite material and PET compared to the enhancement of about 2 times.
3、Glass fiber modified PET
Compared with nanoparticles, micron-sized glass fibers (GF) have outstanding advantages in cost and controllability, and thus are widely used to fill modified polymer materials.
4, PET blending modification
Including PET, two or more polymers in accordance with the appropriate ratio at a certain temperature and shear stress and other conditions, through the melt blending way to form polymer alloys or blends with new properties. Inter-polymer compatibility is the key to the preparation of such polymers.
5, polyolefin modified PET
PET and PE in the chemical structure has obvious differences, does not have compatibility. From the study of simple binary blends of the two, it was found that to improve the impact properties of PET through polymer blend modification, it must be through the means of capacitation to improve the compatibility of the two. In the blended system of HDPE and PET, the impact strength of both EVA and EAA systems were improved by adding EVA and EAA systems.
PET and PP blending, the formation of the alloy has both the strengths of the two, so that the performance has been improved, for example, PET can make PP heat resistance increased, PP can make PET less sensitive to moisture. In the absence of compatibilizers in the role of PET and PP blending, the two-phase interface bonding is very weak, and the mechanical properties are poor.
PET/PS is an incompatible system, and a compatibilizer must be added to achieve the purpose of blending compatibility. It was found that the styrene and acrylic acid glycidyl ester copolymer P (S-GMA) as a reactive compatibilizer added to PET/PS blending system, obtained a better interfacial combination of PET/PS/P (S-GMA) blending system, so that the mechanical properties have been improved.
6, polyester modified PET
PBT is a new type of engineering plastics developed rapidly in the 1970s of the last century, its mechanical properties are better than PET, and there is good toughness, able to molding, but its heat resistance and fluidity are not as good as PET, and the price is higher. According to Teijin reported that in the two blends add 0.5% talc as a nucleating agent, the resulting blend of good impact resistance, low molding shrinkage.
PC's mechanical properties are very good, good toughness, high glass transition temperature, but its fluidity and aging resistance is poor. PET and PC blends can improve the impact strength. The two blends have been industrialized in foreign production, has a wide range of applications in automotive parts.
7, elastomer toughened modified PET
ABS is currently one of the most widely used polymers, it not only has good toughness, but also has a better overall performance than HIPS. PET and ABS blends can make the impact strength of PET improved.
In the study, it was found that the relative molecular mass of PET in the blend is very sensitive to the processing temperature, and the hydrolysis of PET chain is related to the heat and the residual catalyst impurities in ABS.The reduction of the relative molecular mass of PET leads to a great loss of impact properties and ultimate elongation, but has no effect on the modulus and flexural strength.