The mechanical properties of oriented semicrystalline polymers fibers are mainly determined by the semicrystalline morphology in which lamellar crystals and disordered amorphous layers are in staggered arrangement. As a stress transmission channel, amorphous entanglement network can affect the strength and toughness of fiber together with crystalline phase. In this study, the relationship between mechanical properties and amorphous entanglement of oriented poly (-lactic acid) fibers was clarified by studying the cyclic loading characteristics. Based on the Haward-Thakray model of semi-crystalline polymers, the energy contributions of the crystalline phase and the amorphous phase are separated. During the deformation of oriented fiber, the crystal will be broken under the action of tight entanglement network, and the entanglement network can transfer stress well without failure under the action of straight chain. Therefore, although the crystalline phase and the amorphous phase jointly bear the strength, the toughness and fracture behavior mainly affected by the entangled network of the amorphous phase.

中文翻译：

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半结晶聚合物纤维的强度和韧性：分子链缠结的影响


取向半晶聚合物纤维的机械性能主要由片状晶体和无序非晶层交错排列的半晶形态决定。非晶态缠结网络作为应力传递通道，与晶相一起影响纤维的强度和韧性。在本研究中，通过研究循环加载特性，阐明了取向聚乳酸纤维的机械性能和无定形缠结之间的关系。基于半结晶聚合物的Haward-Thakray模型，分离了结晶相和非晶相的能量贡献。取向纤维在变形过程中，晶体在紧密缠结网络的作用下会破裂，而缠结网络在直链的作用下能很好地传递应力而不会失效。因此，虽然晶相和非晶相共同承担强度，但韧性和断裂行为主要受非晶相的缠结网络影响。