The mechanism of fracture for entangled polymer liquids in extensional flow
The mechanism of fracture for entangled polymer liquids in extensional flow
复制标题
拉伸流动中缠结聚合物液体的断裂机理
DOI：
10.1063/1.5108510
复制
发表时间：
2017
影响因子：
2.5
通讯作者：
O. Hassager
中科院分区：
文献类型：
--
作者：
Qian Huang;Liyun Yu;S. L. Wingstrand;A. Skov;O. Hassager
本文系统地研究了两组近似单分散线性聚苯乙烯液体在拉伸流动中的临界应变和断裂应力。组I中的样品具有相似的每个纠缠链的Kuhn段数（Ne），但不同的每个链的纠缠数（Z），而组II中的样品具有相似的Z，但不同的Ne。发现临界条件，特别是临界应力与Z无关，而受Ne的影响。观察结果表明，在纠缠的聚苯乙烯液体断裂发生在一个长度尺度小于纠缠的股。因此，断裂更可能起源于聚合物链中的初级键的断裂，而不是快速缠结滑动。临界应力的水平还表明，在断裂时，聚合物链接近其理论最大拉伸比，其等于ε Ne。由AIP Publishing授权出版。https://doi.org/10.1063/1.5108510., S
The critical strain and stress at fracture are systematically investigated for two groups of nearly monodisperse linear polystyrene liquids in an extensional flow. The samples in group I have similar number of Kuhn segments per entangled strand (Ne) but different number of entanglements per chain (Z), while the samples in group II have similar Z but different Ne. We found that the critical conditions, especially the critical stress, are independent of Z but influenced by Ne. The observations indicate that the fracture in entangled polystyrene liquids occurs at a length scale smaller than an entangled strand. Therefore, the fracture originates more likely from scission of primary bonds in polymer chains, rather than rapid entanglement slipping. The level of the critical stress also suggests that at fracture, the polymer chains approach their theoretical maximum stretch ratio, which is equal to √ Ne. Published under license by AIP Publishing. https://doi.org/10.1063/1.5108510., s