Crystallization behavior and morphological development of isotactic polypropylene with an aryl amide derivative as β-form nucleating agent
Isotactic polypropylene (iPP) is a semi-crystalline polymer with several crystal modifications such asmonoclinicα, trigonal β and orthorhombicγ. Among all the crystal forms of iPE the β one has manyperformance characteristics, such as improved elongation at break and impact strength. The most effective andaccessible method to obtain iPP with higher level of βcrystal form is the addition of some β-nucleating agents.In our laboratory conditions, a commercialized nucleating agent TMB-5 proved to be a highly efficient β-typenucleating agent. We investigate the β nucleating activity of TMB-5 under non-isothermal and isothermalcrystallization conditions and discuss the relationship of additive concentration, thermal history and assemblemorphology of nucleating agent with β form crystal content and the spherulitic morphology of iPP. The heterogeneous efficiency of nucleating agent was clearly valued by virtue of differential scanningcalorimetry (DSC). When samples were cooled at constant rate, the crystallization temperature increased withTMB-5 percentage from 108℃ (pure iPP) to 123℃ (iPP/0.6％TMB-5) (Fig. 1). The results indicate that TMB-5molecules essentially act as effective nucleating agent for iPP matrix and promote the crystallization rate of iPPduring non-isothermal crystallization. The TMB-5 concentration should surpass a threshold value to get productsrich in β-iPP.
isotactic polypropylene nucleating agent crystallization morphology
Mu Dong Zhao-Xia Guo Jian Yu Zhi-Qiang Su
Institute of Polymer Science and Engineering,Department of Chemical Engineering,School of Materials Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials,Beijing Univ
国际会议
5th East-Asian Polymer Conference(第5届东亚高分子学术研讨会)
上海
英文
78-79
2008-06-03（万方平台首次上网日期，不代表论文的发表时间）