Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2009-11-03

Journal: POLYMER

Included Journals: Scopus、EI、SCIE

Volume: 50

Issue: 23

Page Number: 5427-5433

ISSN: 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.