共混型聚丙烯/超细粉末丁苯橡胶全硫化热塑性弹性体的制备及其结构与性能

以全硫化超细粉末丁苯橡胶(PSBR)与聚丙烯(PP)为原料,采用双螺杆挤出机共混方法制备PP/PSBR全硫化热塑性弹性体。通过透射电镜观测,发现PP/PSBR全硫化热塑性弹性体具有和动态硫化方法制备的热塑性弹性体相似的微观形态,PSBR粒子作为分散相分散在连续相PP中;所制备的热塑性弹性体的力学性能与PP的相对分子质量、共聚与否、PSBR含量及其交联度有关;通过流变行为研究,发现此类全硫化热塑性弹性体为假塑性流体,且橡胶的含量对热塑性弹性体的黏度影响很小;采用差示扫描量热法对PP/PSBR全硫化热塑性弹性体中连续相PP的结晶行为进行了研究,发现连续相PP的结晶温度提高,表明PSBR对PP有异相成核作用。

Preparation of fully cured polypropylene/ultrafine powdered styrene-butadiene rubber thermoplastic elastomer and its morphology, structure and properties

A new route to make fully cured thermoplastic elastomer(TPE) was developed through simple blending polypropylene(PP) and ultrafine powdered styrene-butadiene rubber(PSBR)by twin screw extruder. Morphology observation with TEM showed that the morphology of PP/PSBR TPE was similar to that of thermoplastic vulcanizate prepared by dynamic vulcanization method, and the PSBR particles were dispersed in PP matrix. The properties of the obtained PP/PSBR TPE were affected by the type of PP differing in copolymer or homopolymer, relative molecular mass,content of PP and the degree of the crosslinking of PSBR. According to the study on the melt rheology, the obtained PP/ PSBR TPE had pseudoplastic flow properties, and the content of PSBR had little effect on their rheological characteristic. Crystallization behaviour of PP matrix in PP/PSBR TPE was studied by DSC. Comparing with raw PP, the crystallization temperature of the PP matrix in PP/ PSBR TPE increased, showing that PSBR acted as a heterogeneous nucleating agent.