【作者】 周燎原；

【导师】 张爱民； 戴立平；

【作者基本信息】 四川大学 ， 材料工程， 2007， 硕士

【摘要】 在SBS分子链中引入极性基团，使其功能化，可以提高SBS与聚合物间的亲和力与相容性，是拓展SBS应用范围的主要途径。国内外SBS在聚合物改性领域占有重要地位，消费量稳步上升。本项目研究了SBS生产过程中的改性技术，开发适用于改性塑料的极性化TPE产品，并研究极性TPE改性塑料应用技术，促进SBS应用领域和市场的拓展。溶液法SBS接枝马来酸酐研究表明，通过在SBS胶液中分别加入马来酸酐、苯乙烯，AIBN，将反应物控制在59-65℃，搅拌反应制备马来酸酐接枝SBS产品。该工艺温度控制范围小，反应时间需要5-6h，MAH不能完全转化，产品提纯分离难度大，接枝产品容易出现交联，加工性能差。该工艺工业化实施难度大，并且生产成本增加幅度大。溶液法SBS接枝丙烯酸研究表明，通过SBS胶液控制在61-64℃，分多次加入丙烯酸和AIBN组成的混合溶液，反应制备丙烯酸接枝SBS产品。该工艺温度控制范围小，反应时间需要8h，接枝产品容易发生交联，后加工性能差，并且因阻聚剂对苯二酚的影响，产品带浅黄色，不能满足用户需求。SBS环氧化研究表明，通过在SBS溶液中分别加入乙酸酐、甲酸进行环氧化，制备SBS环氧化产品，该工艺同样存在产品提纯分离成本高的问题。SBS接枝乙烯基吡啶研究表明，在SBS胶液中加入代帽试剂，再加入2-乙烯基吡啶制备乙烯基吡啶接枝SBS共聚产品，即极性TPE。合成的极性TPE，大分子含量小于15％，极性化产品拉伸强度明显提高。极性TPE改性聚丙烯研究表明，通过研究不同分子量、不同接枝率及不同嵌段比的极性TPE对PP力学性能的影响，优化选择出了适用于增韧改性聚丙烯极性TPE弹性体；研究了极性TPE与POE的协同增韧作用及极性TPE与PP共混物的表面性能，发现极性TPE与POE具有较好的协效作用，少量极性TPE与POE复合改性聚丙烯材料的冲击韧性和涂饰性明显提高，极性TPE改性聚氯乙烯研究，通过优化、筛选配方，研究了极性TPE对PVC／SBS体系力学性能的影响、CPE与极性TPE复合对PVC／SBS体系的协同增容效应及极性TPE对PVC／ABS体系力学性能的影响，发现极性TPE或极性TPE与CPE复合均可明显改善PVC／SBS体系的相容性，提高体系的冲击韧性；少量极性TPE既可提高PVC／ABS体系综合力学性能，又可减少ABS加入量，降低材料成本。特别适用于刚性要求适中，低温冲击性能要求较高的PVC／ABS合金制品。通过一系列实验研究得出以下结论：(1)极性TPE分子量、接枝率及S／B嵌段比对聚丙烯／极性TPE体系各项性能影响不同。较低分子量、接枝率适中、S／B嵌段比较高的极性TPE改性聚丙烯的综合效果最好，适用于改性聚丙烯体系。(2)极性TPE与聚丙烯的相容性随聚丙烯结构不同而不同，极性TPE与均聚聚丙烯的相容性要好于与共聚聚丙烯的相容性。(3)极性TPE对共混聚丙烯材料表面极化度贡献的效果明显好于接枝聚丙烯对共混聚丙烯材料表面极化度的贡献。(4)少量极性TPE与POE弹性体复配改性聚丙烯的增韧及涂饰性效果明显优于单独使用POE弹性体改性聚丙烯的效果，有较好的推广应用前景。(5)极性化SBS作为相容剂使用，与SBS复合改性PVC的效果明显优于单独SBS改性PVC的效果。SBS／极性化SBS比值达到10／5时，PVC／SBS／极性化SBS体系的冲击韧性最高。(6)CPE与SBS复合改性PVC的效果好于极性SBS与SBS复合改性PVC和CPE与SBS复合改性的效果。(7)少量极性TPE可作为PVC／ABS共混体系的相容剂，明显提高体系的冲击性能，材料的低温(-20℃)简支梁缺口冲击强度可达70KJ／m~2以上，具有较好的性价比和应用前景。尤其适用于刚性要求适中，低温冲击性能要求较高的PVC／ABS合金制品。更多还原

【Abstract】 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.更多还原