首页> 外文OA文献 >Crystallization and melting behavior of the crystalline soft segment in a shape-memory polyurethane ionomer
【2h】

Crystallization and melting behavior of the crystalline soft segment in a shape-memory polyurethane ionomer

机译:形状记忆聚氨酯离聚物中结晶软链段的结晶和熔融行为

摘要

To illustrate the crystallization properties of soft segments in shape-memory polyurethane (SMPU) ion-omers, a series of SMPU ionomers with various ionic group contents and two kinds of counterions were synthesized with a prepolymerization method. An isothermal crystallization kinetic method was used to analyze the effects of ionic groups within the hard segments on the crystallization of the soft segments in a heating and cooling routine similar to that in a shape-memory function. The more ionic groups there were within the hard segments, the lower the crystallization rate was of the soft segments. The crystallization mechanism of the SMPU ionomers was quite close to that of a control sample on the basis of similar Avrami exponents; the counterion category also had some influence on the crystallization rate. Meanwhile, the melting behavior after isothermal crystallization reflected the fact that the thermal history of the hard segments had a huge effect on the crystallization mechanism of the soft segments. Especially for the SMPU ionomer quenched from 240°C, the crystallization time dependence of the secondary crystallization was rather significant, but for the SMPU ionomer quenched from 70°C, the primary crystallization of the poly(ε-caprolactone) soft segment was predominant.
机译:为了说明形状记忆聚氨酯(SMPU)离子聚合物中软链段的结晶特性,采用预聚合方法合成了一系列具有不同离子基团含量的SMPU离聚物和两种抗衡离子。采用等温结晶动力学方法,以类似于形状记忆功能的加热和冷却程序分析硬链段中的离子基团对软链段结晶的影响。硬链段内的离子基团越多,软链段的结晶速率越低。基于相似的Avrami指数,SMPU离聚物的结晶机理与对照样品的结晶机理非常接近。抗衡离子类别也对结晶速率有一定影响。同时,等温结晶后的熔融行为反映了这样的事实,即硬链段的热历史对软链段的结晶机理有很大的影响。特别是对于从240°C淬灭的SMPU离聚物,二次结晶的结晶时间依赖性非常显着,但是对于从70°C淬灭的SMPU离聚物,聚(ε-己内酯)软链段的主要结晶是主要的。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号