MACROCYCLIZATION VERSUS POLYMERIZATION IN POLYCONDENSATION REACTIONS UNDER HIGH-DILUTION CONDITIONS - A THEORETICAL-STUDY
MACROCYCLIZATION VERSUS POLYMERIZATION IN POLYCONDENSATION REACTIONS UNDER HIGH-DILUTION CONDITIONS - A THEORETICAL-STUDY
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DOI：
10.1021/j100343a077
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发表时间：
1989-03-23
影响因子：
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通讯作者：
FASTREZ, J
中科院分区：
文献类型：
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作者：
FASTREZ, J
线型缩聚聚合物的形成动力学和分子尺寸分布早在许多年前就由Flory 1发展起来了，并且在这个理论模型中仍然引入了修正。2在所有这些研究中，几乎没有明确考虑环状低聚物的形成，尽管已知在许多缩合物中存在环状低聚物。3随着大环化学的发展和人们对冠醚、疏水性大环或多环化合物的广泛兴趣，需要理论模型来预测各种大环和聚合物中反应条件和系统参数对反应产率的影响。由于环化反应为一级反应，而底物中的聚合反应为二级反应，因此在高稀释条件下有利于大环化合物的形成。这一点已经在拉格里的工作中指出，45678没有引起注意，后来在鲁西卡、齐格勒、卡罗瑟斯和所罗门的重要贡献中也指出了这一点。5-8对大环化学的新兴趣导致了一些关于环闭合与聚合动力学的更详细的研究：特别是描述了游戏板蒙特卡罗方法9 1011*，并对有限的一系列动力学方程进行了分析或数值积分。1011
The kinetics of formation of linear condensation polymers and the molecular size distribution have been developed many years ago by Flory, 1 and refinements are still introducedin this theo-retical model. 2 In all these studies, the formation of cyclic oligomers is hardly considered explicitly, although these are known to be present in many polycondensates. 3 With the development of macrocyclic chemistry and the con-siderable interest in compounds like crown ethers, hydrophobic macrocycles, or polycycles, there is a need for theoretical models that could lead to predictions about the influence of the conditions of reaction and parameters of the systems on the yields of reactions in the various macrocycles and polymers. The formationof macrocycliccompounds can be favored by working under high dilution because the cyclization is a first-order process while the polymerization is second order in substrate. This was already pointed out in the work of Ruggli, 4 5678which attracted little attention, and later in the important contributions of Rusicka, Ziegler, Carothers, and Salomon. 5-8 The renewed interest in macrocyclic chemistry has led to a few more detailed studies on the kinetics of ring closure versus polymerization: particularly, a playing board Monte Carlo approach has been described9 1011* and analytical or numerical integrationof a limited series of kinetic equations has been conducted. 1011