Study On Polarized TPE Modifying Plastic

The affinity and compatibility can be improved between SBS and compound through adding polar group to SBS molecular chain and making SBS function. This method is the main process to widen its application. SBS has an important position in polymer modification, and the amount of its consumption has been improved steadily. This article has studied the modification technology in the production of SBS, the suitable polarized TPE used to modify polyolefin and the application technology, so as to widen its application and market.The grafted polymer of SBS-g-MAH are prepared through solution method by adding MAH, styrene and AIBN to SBS gum liquid respectively, controlling the reaction temperature to 59-65 degree and stirring. The results show that the field of temperature is too narrow, the reaction time is 5-6 hours, MAH can not be transformed completely, purifying is difficulty, the grafted polymer can be crosslinked easily and the processing property is not good. This process is hard to be industrialized, and the cost of production is high.Through solution method, the grafted polymer of SBS-g-acrylate are prepared by adding acrylate and AIBM compound to SBS gum liquid repetitive times and controlling the reaction temperature to 61-64 degree. The results show that the range of temperature is too small, the reaction time is 8 hours, the grafted compound can be crosslinked easily, the processing property is not good, the product is light yellow due to the influence of inhibitor on hydroquinone, and it can not satisfy the demand of users.SBS epoxidation product is prepared by adding acetic anhydride and formic acid to SBS gum liquid respectively, and makes them epoxidation. The cost of purifying is also high.The grafted polymer of SBS-g-vinylpyridine are prepared by adding epoxy propane equimolar to lithium to SBS gum liquid, then adding 2-vinylpyridine to produce the grafted compound TPE. The content of macromolecule of polarized-TPE is below 15%, the tensile strength has been improved.It is studied that the effect of polarized TPE with different molecular weight, graft rate and S/B on the mechanical performances of PP, the suitable elastomer is chosen for toughening PP and polarized TPE. The cooperative and compatibility effect of POE and polarized TPE, the performances of PP/TPE have been investigated. The results have shown that polarized TPE and POE have excellent compatibility. A small amount of polarized TPE can improve the impact toughness and the painting properties.Through optimization and screening formulation, the effect of polarized TPE on the mechanical performances of PVC/SBS, the cooperative compatibility, effect of CPE and polarized TPE on the mechanical performances of PVC/ABS have been investigated. The results have shown that polarized TPE or polarized TPE and CPE both can significantly improve the compatibilization of PVC/SBS, increase its impact toughness; a small amount of polarized TPE not only can improve the comprehensive mechanical performances of the PVC/ABS, but also can reduce the amount of ABS, therefore reduce cost, it is especially suitable for PVC/ABS articles requiring medium stiffness and high impact performance at low temperature.The investigations have shown:(1) The molecular weight, grafting efficiency and S/B block ratio of polarized-TPE has different effects on the performances of polypropylene/polarized-TPE system. Polarized-TPE modified PP with lower molecular weight and higher S/B ratios has better performances, and are suitable for modified PP.(2) The compatibility of Polarized-TPE and PP is dependent on the structure of PP; polarized-TPE has better compatibility with homo-PP than with PP copolymer.(3) In terms of contribution to the surface polarized degree of the PP compound, Polarized-TPE is greater than grafted-PP.(4) The effect of toughness-enhancement and coating with a small amount of polarized-TPE and POE elastomer compounds modified PP is better than only POE modified PP, and has a bright application prospect.(5) As a compatibilizer, the effect of polarized SBS and SBS compounds modified PVC is better than SBS alone. When the ratio of SBS and polarized-SBS has reached 10/5, the PVC/SBS/polarized-SBS system has the highest impact toughness.(6) The effect of CPE and SBS modified PVC is better than polarized SBS and modified PVC and CPE and SBS.(7) A small amount of TPE can be used as a compatibilizer for PVC/ABS system to significantly improve the impact performance of this system, free beam notch impact strength at low temperature(-20℃) of this material is more than 70KJ/m2, and have better performance and price ratio and bright prospect, especially suitable for PVC/ABS articles requiring medium stiffness and high impact performance at low temperature.