Study of the crystallization behaviors of isotactic polypropylene with sodium benzoate as a specific versatile nucleating agent |
| |
Authors: | Mu Dong Zhaoxia Guo Zhiqiang Su Jian Yu |
| |
Institution: | 1. Department of Chemical Engineering, Institute of Polymer Science and Engineering, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China;2. Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing, People's Republic of China |
| |
Abstract: | Sodium benzoate (SB), a conventional nucleating agent of α‐phase isotactic polypropylene (iPP) was discovered to induce the creation of β‐phase iPP under certain crystalline conditions. Polarized optical microscopy (POM) and wide angle X‐ray diffraction (WAXD) were carried out to verify the versatile nucleating activity of SB and investigate the influences of SB's content, isothermal crystallization temperature, and crystallization time on the formation of β‐phase iPP. The current experimental results indicated that, under isothermal crystallization conditions, SB showed peculiar nucleating characteristics on inducing iPP crystallization which were different from those of the commercial β form nucleating agent (TMB‐5). The content of β crystal form of iPP nucleated with SB (PP/SB) increased initially with the increase of crystallization temperature, nucleating agent (SB) percentage or crystallization time, reached a maximum value, and then decreased as the crystallization temperature, nucleating agent percentage or crystallization time further increased. While the content of β crystal form of iPP nucleated with TMB‐5 (PP/TMB‐5) showed a completely different changing pattern with the crystallization conditions. The obvious difference of the two kinds of nucleating agents on inducing iPP crystallization can be explained by the versatile nucleating ability of SB. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1183–1192, 2008 |
| |
Keywords: | crystallization isotactic polypropylene nucleation polarized optical microscopy poly(propylene) PP sodium benzoate versatile nucleating agent wide‐angle X‐ray diffraction |
|
|