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首页> 外文期刊>Journal of Applied Polymer Science >A kinetic investigation of polyurethane polymerization for reactive extrusion purposes
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A kinetic investigation of polyurethane polymerization for reactive extrusion purposes

机译：聚氨酯聚合反应挤出的动力学研究

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The effects of the reaction conditions on the kinetics of two different polyurethane systems were investigated. To do so, three different kinetic methods were compared: adiabatic temperature rise (ATR), measurement kneader, and high-temperature measurements. For the first polyurethane system, consisting of 4,4-diphenylmethane diisocyanate (4,4-MDI), butane diol, and a polyester polyol, the reaction conditions did not seem to matter; a kinetically controlled reaction was implicated for all reaction conditions. The reaction was second order in isocyanate concentration and 0.5th order in catalyst concentration and had an activation energy of 52 kJ/mol. The second polyurethane system consisted of a mixture of 2,4-diphenylmethane diisocyanate and 4,4-MDI, methyl propane diol, and a polyester polyol. For this system, each of the three measurement methods showed different behavior. Only at a low catalyst concentration did the ATR experiments show catalyst dependence; at higher catalyst levels and for the other two measurement methods, no catalyst dependence was present. Furthermore, the ATR experiments proceeded much faster. Presumably, for this system, the rapid diffusion interfacial of the species present was hindered by the presence of bulky oligomer molecules. The result was a diffusion limitation reaction at low conversions and an inhomogeneous distribution of species at higher conversions. (c) 2006 Wiley Periodicals, Inc.
机译：研究了反应条件对两种不同聚氨酯体系动力学的影响。为此，比较了三种不同的动力学方法：绝热温升（ATR），测量捏合机和高温测量。对于由4，4-二苯基甲烷二异氰酸酯（4,4-MDI），丁二醇和聚酯多元醇组成的第一个聚氨酯体系，反应条件似乎无关紧要。涉及所有反应条件的动力学控制反应。反应的异氰酸酯浓度为二级，催化剂浓度为0.5级，活化能为52kJ / mol。第二聚氨酯体系由2，4-二苯基甲烷二异氰酸酯和4，4-MDI的混合物，甲基丙二醇和聚酯多元醇组成。对于此系统，三种测量方法中的每一种都显示出不同的行为。只有在低催化剂浓度下，ATR实验才显示出对催化剂的依赖性。在较高的催化剂水平下，对于其他两种测量方法，不存在催化剂依赖性。此外，ATR实验进行得更快。据推测，对于该系统，存在的物质的快速扩散界面被庞大的低聚物分子的存在所阻碍。结果是低转化率下的扩散限制反应和高转化率下物种的不均匀分布。 （c）2006年Wiley Periodicals，Inc.

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