Indexed by:期刊论文

Date of Publication:2009-11-03

Journal:POLYMER

Included Journals:SCIE、EI、Scopus

Volume:50

Issue:23

Page Number:5427-5433

ISSN No.:0032-3861

Key Words:Stereotriblock polybutadiene; Cold crystallization; Anionic polymerization

Abstract:A series of high trans-1,4-low-cis-1,4-high trans-1,4-stereotriblock polybutadienes (HTPB-b-LCPB-b-HTPBs) were synthesized through a sequential anionic polymerization of butadiene (Bd) initiated by barium salt of di(ethylene glycol) ethylether/triisobutylaluminium/dilithium (BaDEGEE/TIBA/DLi). The polymers consisted of elastic low-cis-1,4-polybutadiene (LCPB) chemically bonded with crystallizable high trans-1,4-polybutadiene (HTPB). The block ratios (HTPB:LCPB:HTPB) were designed at 25:50:25 (molar ratio) and finally determined by SEC. The microstructures and sequences of the specimens were investigated by FTIR and NMR. The resultant HTPB-b-LCPB-b-HTPBs consisted of LCPB block with 52.5% trans-1,4 content and HTPB block with 55.9-85.8% trans-1,4 content. According to differential scanning calorimetry (DSC), HTPB-b-LCPB-b-HTPB showed a significant cold crystallization which was discussed in terms of entanglement concept. The cold crystallization temperature (T(cc)) decreased whereas the melting temperature (T(m)) increased with the increasing trans-1,4 content of HTPB block. (C) 2009 Elsevier Ltd. All rights reserved.