Thermally stimulated shape-memory behavior of ethylene oxide-ethylene terephthalate segmented copolymer

✍ Scribed by Xiaolie Luo; Xiaoyun Zhang; Mingtai Wang; Dezhu Ma; Mao Xu; Fengkui Li

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 273 KB
• Volume: 64
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970620)64:12<2433::aid-app17>3.0.co;2-1

✦ Synopsis

A series of ethylene oxide-ethylene terephthalate segmented copolymers (EOET) with different long soft segments and different hard-segment contents were synthesized. The thermally stimulated shape-memory behavior of EOET segmented copolymer is characterized by the maximum recovery (R f ), the recovery temperature (T r ), and the recovery speed (V r ) or the temperature ( T M ) of the maximum deformation recovery rate against temperature and the maximum recovery speed (V M ). These parameters show that the features of thermally stimulated shape-memory effects of EOET segmented copolymers are following: The crystallinity of soft segments determines the temperature T r and T M , and the parameters R f , V r , and V M depend on the stability of the physical crosslinks formed by the hard segments, which at the same time are influenced by the length of soft segment. R f , V r , and V M decrease with prolongation of the keeping time (t k ) and increasing stretching ratio.