文献类型：期刊文献

英文题名：Shape memory properties of polycaprolactone-based polyurethanes prepared by reactive extrusion

作者：Weng, Shengguang[1];Xia, Zhean[1];Chen, Jianding[1];Gong, Luanluan[1]

机构：[1]E China Univ Sci & Technol, Sch Mat Sci & Engn, Minist Educ, Shanghai Key Lab Adv Polymer Mat,Key Lab Ultrafin, Shanghai 200237, Peoples R China

年份：2013

卷号：127

期号：1

起止页码：748

外文期刊名：JOURNAL OF APPLIED POLYMER SCIENCE

收录：;EI(收录号：20124215581557);WOS:【SCI-EXPANDED(收录号:WOS:000309594400094)】；

基金：The authors thank Shanghai International Science and Technology Cooperation Funding (grant number 06SR07103), Shanghai Leading Academic Discipline Project (grant number B502), and Shanghai Key Laboratory Project (grant number 08DZ2230500).

语种：英文

外文关键词：block copolymers; polyurethanes; reactive extrusion; structure-property relations

摘要：The shape memory properties of polycaprolactone-based polyurethanes (PCLUs) synthesized via a novel route of reactive extrusion were investigated in terms of the deformation amplitude, temperature, and rate by differential scanning calorimetry (DSC), dynamic mechanical analyzer, and polarized optical microscopy (POM). DSC analysis shows that the crystalline melting temperature and crystallinity of PCLU increased monotonically with increasing the average polymerization degree $ ( \overline {DPn}) $ of poly(e-caprolactone) (PCL) block. The retract force increased with increasing the temperature and reached the maximum (67 MPa) within 45-55 degrees C. Furthermore, a modified model with two recovery stages was postulated to elucidate the shape memory process, which is visually presented by POM analysis. The two stages of tensile and compressive recovery are distinguished by the inflexion temperature, within 43-48 degrees C and 6466 degrees C, respectively. The shape fixity is about 60-70% and can be improved to 100% by choosing proper deformation temperature. The tensile deformation recovery ratio was 80-98% due to the water absorption, whereas the compressive deformation recovery ratio was almost 100%. Besides, recovery tests show that the lowest recovery temperature ranged from 24 to 47 degrees C was influenced by the deformation temperature, rate and the PCL block $ ( \overline {DPn}) $. Thus, the shape memory properties can be adjusted according to different purposes. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012