The criterion for brittle fracture of entangled polymer liquids [Wagner et al., J. Rheol. 62, 221–223 (2018)] is extended by including the effects of finite chain extensibility and polymer concentration. Crack initiation follows from rupture of primary C–C bonds, when the strain energy of entanglement segments reaches the energy of the covalent bond. Thermal fluctuations will concentrate the strain energy on one C–C bond of entanglement segments, leading to bond scission and rupture of polymer chains followed by crack initiation and fast crack growth. In start-up flows, entanglement segments characterized by long relaxation times, i.e., predominantly those in the middle of the polymer chain, will be the first to reach the critical strain energy and will fracture. Recent experimental data of Huang [Phys. Fluids 31, 083105 (2019)] of fracture of a monodisperse polystyrene melt and of several solutions of monodisperse polystyrenes dissolved in oligomeric styrene are in agreement with the scaling relations for critical Weissenberg number as well as Hencky strain and stress at fracture derived from this fracture criterion and the extended interchain pressure model [Narimissa, Huang, and Wagner, J. Rheol. 64, 95–110 (2020)].

中文翻译：

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纠缠的聚苯乙烯熔体脆性断裂的尺度关系和伸长流中的溶液

缠结的聚合物液体脆性断裂的判据[Wagner et al。，J. Rheol。62，221-223（2018）]由包括有限链的扩展性和聚合物浓度的影响延长。当缠结链段的应变能达到共价键的能量时，主要的C–C键的断裂会引发裂纹。热波动将使应变能集中在一个缠结链段的C–C键，导致聚合物链的键断裂和断裂，随后出现裂纹引发和快速裂纹扩展。在启动流中，以长弛豫时间为特征的纠缠段（即主要位于聚合物链中间的纠缠段）将首先达到临界应变能并断裂。黄的最新实验数据 流体31单分散聚苯乙烯的骨折，083105（2019）]熔化并溶解在低聚苯乙烯单分散聚苯乙烯的几种解决方案都与关键魏森伯格数目的缩放关系协议以及亨基应变和应力从这个断裂衍生的断裂准则和扩展的链间压力模型[Narimissa，Huang和Wagner，J.Rheol。64，95-110（2020）]。