An improved kinetic model for the radical polymerization of N‐vinyl‐pyrrolidone (NVP) in aqueous medium is developed. Quantum chemical simulations reveal that the transfer to polymer is of minor importance whereas the transfer to monomer by hydrogen abstraction in 3‐position of the pyrrolidone ring leads to a radical with a double bond which initiates a new chain bearing a terminal double bond (TDB). The resulting dead chains with one, two, or more TDB are the main source for a strong increase of molar mass in batch reactors at high conversion due to long chain branching and crosslinking. This can be a source for gel formation and fouling in continuous reactors.

中文翻译：

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N-乙烯基-吡咯烷酮在水相聚合中的副反应可能是结垢的来源

建立了改进的N-乙烯基吡咯烷酮（NVP）在水性介质中自由基聚合的动力学模型。量子化学模拟表明，转移至聚合物的重要性不大，而在吡咯烷酮环的3位通过氢提取转移至单体的转移会导致具有双键的自由基，从而引发一条带有末端双键（TDB）的新链。由于长链支化和交联，具有高，高转化率的间歇反应器中摩尔质量的强烈增加的主要来源是产生的具有一个，两个或多个TDB的死链。这可能是连续反应器中凝胶形成和结垢的来源。