Multifunctional coupling agents. II. Chain extension and terminal group modification of polyamides
Multifunctional coupling agents. II. Chain extension and terminal group modification of polyamides
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DOI：
10.1002/app.21159
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发表时间：
2004-12
影响因子：
3
通讯作者：
L. Jakisch;H. Komber;R. Wursche;F. Böhme
中科院分区：
文献类型：
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作者：
L. Jakisch;H. Komber;R. Wursche;F. Böhme
以尼龙6和尼龙12为原料，在哈克熔融共混机或挤出机中转化了含有1个2-恶唑啉基和1个2-恶唑烷酮基团的新型双官能团偶联剂。核磁共振波谱研究表明，2-恶唑啉基团主要与羧基反应，恶嗪酮基团与氨基反应较好。这两个反应都有很高的选择性，而且相互独立。在羧基/氨基终止的聚酰胺的情况下，由于偶联剂同时寻址了聚酰胺的两个反应性末端基团，因此转化导致了分子量的增加。在氨基封端的聚酰胺的情况下，与双官能团偶联剂的转化得到了恶唑啉封端的聚合物链。与PA6不同的是，可以分两步转换PA12。在较低的温度(210℃)和较短的反应时间(2min)下，恶唑酮基团与氨基的反应占主导地位，而恶唑啉基团与羧基的反应只有在较长的反应时间或较高的温度下才能进行足够的程度。对于PA6，需要大约250°C的加工温度。在这里，观察到一个副反应，导致在水的演化下形成环状喹恶啉结构。这种副反应并没有显著干扰链的延伸。©2004威利期刊公司应用多学科期刊94：2170-2177,2004
New bifunctional coupling agents possessing one 2-oxazoline group and one 2-oxazinone group were converted in a Haake melt mixer or extruder with PA6 and PA12. It was shown by means of NMR spectroscopic investigations that the 2-oxazoline group reacted mainly with carboxylic groups whereas the oxazinone group reacted preferably with the amino groups. Both reactions proceeded with high selectivity and independent from each other. In the case of carboxy/amino group terminated polyamides, the conversions resulted in increased molecular weights since both reactive terminal groups of the polyamides were addressed simultaneously by the coupling agent. In the case of amino group terminated polyamides, the conversion with the bifunctional coupling agent resulted in oxazoline terminated polymer chains. Unlike PA6, it was possible to convert PA12 in two steps. At lower temperatures (210°C) and short reaction times (2 min), the reaction of the oxazinone group with the amino groups was predominant, whereas the reaction of the oxazoline group with the carboxylic groups proceeded to a sufficient extent only after longer reaction times or at higher temperatures. In the case of PA6, processing temperatures of about 250°C were necessary. Here, a side reaction was observed that resulted in the formation of cyclic quinoxaline structures under evolution of water. This side reaction did not disturb the chain extension significantly. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2170–2177, 2004