Structure and Properties of Model Polybutadienes and HIPS: Effect of Rubber Microstructure on HIPS Dynamic Mechanical Properties

High impact polystyrene (HIPS) series was synthesized by the mass-suspension process using polybutadiene (PB) rubbers with different cis-1,4, trans-1,4, and vinyl-1,2 isomers content. The HIPS were characterized by TEM, GPC, DMA, and DSC analyses. It was found that the dynamic mechanical properties of HIPS strongly depend upon the microstructure of PB used as a modifier due to the different tendency of PB isomers to promote grafting, cross-linking, and crystallization. The DMA for HIPS synthesized from high cis and high trans rubbers show additional relaxations at the low temperature region. The DSC results for gels extracted from these HIPS exhibited melting endotherms confirming the existence of crystalline domains. *Author to whom correspondence should be addressed. E-mail: [email protected] JOURNAL OF ELASTOMERS AND PLASTICS Vol. 38–April 2006 133 0095-2443/06/02 0133–14 $10.00/0 DOI: 10.1177/0095244306057255 2006 SAGE Publications © 2006 SAGE Publications. All rights reserved. Not for commercial use or unauthorized distribution. at PENNSYLVANIA STATE UNIV on February 8, 2008 http://jep.sagepub.com Downloaded from