Brittle fracture in associative polymers: the case of ionomer melts.
Brittle fracture in associative polymers: the case of ionomer melts.
复制标题
缔合聚合物的脆性断裂：离聚物熔化的情况。
DOI：
10.1039/c6sm01441k
复制
发表时间：
2016
期刊：
影响因子：
3.4
通讯作者：
O. Hassager
中科院分区：
文献类型：
--
作者：
A. Shabbir;Qian Huang;Quan Chen;R. Colby;N. Alvarez;O. Hassager
离聚物因其在涂料、粘合剂、薄膜和包装材料中的应用而备受关注。因此，对离聚物断裂的潜在机制的研究既具有实践意义，又具有理论意义。在这项研究中，我们采用高速成像与单轴拉伸流变测量相结合来描述导致离聚物熔体脆性断裂的机理。当这些离聚物以高于物理交联的逆弛豫时间的速率伸长时，在临界应力下会发生边缘断裂。抛物线断裂剖面证明该现象是纯弹性现象，体积耗散对裂纹剖面影响很小。实验结果在线弹性材料的格里菲斯理论和粘弹性材料的德热内斯理论中进行解释。
Ionomers are interesting due to their applications in coatings, adhesives, films and packaging materials. A study of the underlying mechanisms for fracture in ionomers is consequently of both practical as well as theoretical interest. In this study, we employ high speed imaging coupled with uniaxial extensional rheometry to delineate the mechanics leading to the brittle fracture of ionomer melts. When these ionomers are elongated at a rate higher than the inverse relaxation time of physical crosslinks, an edge fracture occurs at a critical stress. Parabolic fracture profiles provide evidence that the phenomenon is purely elastic and bulk dissipation has little impact on the crack profile. Experimental results are interpreted within the Griffiths theory for linear elastic materials and the de Gennes theory for viscoelastic materials.