Folding of Polymer Chains in the Early Stage of Crystallization

详细信息    查看全文

• 作者：Shichen Yuan ; Zhen Li ; You-lee Hong ; Yutian Ke ; Jia Kang ; Akihiro Kamimura ; Akihiro Otsubo ; Toshikazu Miyoshi
• 刊名：ACS Macro Letters
• 出版年：2015
• 出版时间：December 15, 2015
• 年：2015
• 卷：4
• 期：12
• 页码：1382-1385
• 全文大小：266K
• ISSN：2161-1653

文摘

Understanding the structure formation of an ordered domain in the early stage of crystallization is one of the long-standing issues in polymer science. In this study, we investigate the chain trajectory of isotactic polypropylene (iPP) formed via rapid and deep quenching, using solid-state NMR spectroscopy. Comparisons of experimental and simulated ¹³C鈥?sup>13C double quantum (DQ) buildup curves demonstrated that individual iPP chains adopt adjacent re-entry sequences with an average folding number 鉄?i>n鉄?= 3鈥? in the mesomorphic form, assuming an adjacent re-entry fraction 鉄?i>F鉄?of 100%. Therefore, long flexible polymer chains naturally fold in the early stage of crystallization, and folding-initiated nucleation results in formation of mesomorphic nanodomains.