高等学校化学学报

高等学校化学学报 ›› 2001, Vol. 22 ›› Issue (11): 1919.

• 研究论文 • 上一篇    下一篇

不同分子量软链段的聚己内酯型聚氨酯扩链反应动力学研究

陆宇琛, 罗筱烈, 马敬文, 张忠平, 马德柱   

  1. 中国科学技术大学高分子科学与工程系, 合肥 230026
  • 收稿日期:2000-11-06 出版日期:2001-11-24 发布日期:2001-11-24
  • 通讯作者: 马德柱(1936年出生),男,教授,博士生导师,从事多嵌段聚合物结构与性能的研究.
  • 基金资助:

    国家自然科学基金(批准号:29374176)资助

Studies on Chain Extension Reaction of Poly( ε-caprolactone) Segmented Polyurethane with Different Soft-segmentmolecular Weights

LU Yu-Chen, LUO Xiao-Lie, MA Jing-Wen, ZHANG Zhong-Ping, MA De-Zhu   

  1. Department of Polymer Science Engineering, USTC, Hefei 230026, China
  • Received:2000-11-06 Online:2001-11-24 Published:2001-11-24

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被引次数

19

摘要： 合成了一系列不同分子量的聚己内酯,进而制备异氰酸根封端的聚己内酯预聚体,用傅里叶变换红外光谱研究了不同分子量的聚己内酯预聚体与二元醇的扩链反应.扩链反应动力学研究结果表明:聚己内酯预聚体与二元醇的扩链反应均为二级反应;随着软链段反应物料分子量的增加,反应速率常数显著降低,但当分子量超过某一范围后,其对反应速率的影响逐渐减小,趋于不变.对于不同硬链段反应物料含量的扩链反应体系,硬链段反应物料含量越高,软链段反应物料分子量对反应速率的影响越明显,而且,当软链段反应物料分子量超过某一范围后,不同体系的反应速率常数间的差值趋于不变.Arrhenius方程中的指前因子(B)随软链段反应物料分子量的变化关系与速率常数对分子量的依赖关系相同;从反应速率常数对温度的依赖关系可见:表观活化能的直线斜率基本相同,扩链反应的活化能主要与官能团的反应活性相关.

关键词: 聚己内酯型聚氨酯, 扩链反应, 软链段反应物料分子量, 硬链段反应物料含量

Abstract: Aseries of poly(ε-caprolactone) segmented polyurethane with different molecular weights (PCL) were synthesized. The kinetics of the chain extension reaction was studied by infrared (IR) spectroscopy. The kinetics parameters show the following characteristics of the chain extension reaction. The rate constants decrease with increase in the number average molecular weightmn of the soft segment at the same hard segment reactant content. The influences of Mn on the reaction rate vary with the variation of the hard segment reactant contents. All of the chain extension reactions studied in this work were of second order. The activation energies were essentially insensitive to the Mn, but they increased a little with increase of hard segment reactant content.

Key words: Poly(ε-caprolactone) segmented polyurethane, Chain extension reaction, Soft segment reactant molecular weight, Hard segment reactant content

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