Novel polyisobutylene stars.: XXIII.: Thermal, mechanical, and processing characteristics of poly(phenylene ether)/polydivinylbenzene(polyisobutylene-b-polystyrene)37 blends

The objective of these investigations was to increase the use temperature of novel star-block polymers consisting of a crosslinked polydivinylbenzene (PDVB) core from which radiate multiple poly(isobutylene-b-polystyrene) (PIB-b-PSt) arms, abbreviated by PDVB(PIB-b-PSt)(n). We achieved this objective by blending star-blocks with poly(phenylene oxide) (PPO) that is miscible with PSt. Thus, various PPO/PDVB(PIB-b-PSt) blends were prepared, and their thermal, mechanical, and processing properties were investigated. The hard-phase glass-transition temperature of the blends could be controlled by the amount (wt%) of PPO. The blends displayed superior retention of tensile strengths at high temperatures as compared to star blocks. The melt viscosities of blends with low weight percentages of PPO were lower than those of star blocks. (C) 10928 Wiley Periodicals, Inc.