We utilized two structurally different long chains (linear and branched ultra-high molecular weight polyethylene) to reveal the dependence of flow-induced crystallization on long chain architecture, and prepared two bi-disperse systems of 98 wt% short chain and 2 wt% long chain. A flow field was applied to the bi-disperse polyethylene melt by a modified injection-molding machine, known as oscillation shear injection molding (OSIM). For the first time, the structural influence of long chains on flow-induced shish-kebab formation was systematically investigated. For the intermediate layer of OSIM samples, the branched long chains were better than the linear long chains at inducing shishkebab formation, agreeing with the reported literatures, because the branches can maintain their oriented conformations longer. But unexpectedly, the reverse is the case for the core layer of OSIM samples, where the shear flow was much weaker than the intermediate layer. To understand the unexpected phenomenon, the lifetime of shishes induced by different long chains was compared. Result demonstrated that the linear-induced shishes possessed higher thermal stability than the branched-induced ones so that the linear-induced shishes could survive in the core layer of OSIM samples. Additionally, unlike other methods for flow-induced crystallization, OSIM could create samples for measuring mechanical properties, and thus offer the chance to reveal the relationship between structure and performance. The mechanical results demonstrated that both long chains remarkably enhanced the mechanical properties because of the significant promoting effect of long chains and intense flow fields on shish-kebab formation. However, the linear long chains induced more stable and flawless shishes with higher tensile strength and modulus (80.4 and 1613.5 MPa, respectively) than the branched ones (74.4 and 1489.3 MPa). Our research not only helps elucidate the mechanism of shish-kebab formation but also provides a better choice to reinforce polymers by adding long chains with suitable structure.

我们利用两条结构不同的长链（线性和支化超高分子量聚乙烯）揭示了流致结晶对长链结构的依赖性，并制备了两个98％短链和2 wt％长链的双分散体系链。通过改进的注模机（称为振荡剪切注模法（OSIM））将流场应用于双分散聚乙烯熔体。首次系统地研究了长链对流动诱导的烤肉串形成的结构影响。对于OSIM样品的中间层，支链长链在诱导烤肉串形成方面比线性长链更好，这与已报道的文献一致，因为支链可以保持更长的取向构象。但是出乎意料的是 对于OSIM样品的核心层，情况恰恰相反，那里的剪切流比中间层弱得多。为了了解这种意外现象，比较了不同长链引起的带光泽的寿命。结果表明，线性诱导的菜谱比分支诱导的菜谱具有更高的热稳定性，因此线性诱导的菜谱可以在OSIM样品的核心层中存活。此外，与其他用于流动诱导结晶的方法不同，OSIM可以创建用于测量机械性能的样品，从而提供了揭示结构与性能之间关系的机会。力学结果表明，由于长链的显着促进作用和强烈的流场对烤肉串的形成，两条长链均显着提高了机械性能。但是，线性长链比支链（74.4和1489.3 MPa）具有更高的拉伸强度和模量（分别为80.4和1613.5 MPa），诱导出更加稳定和完美的粉刺。我们的研究不仅有助于阐明烤肉串的形成机理，而且还通过添加具有适当结构的长链为增强聚合物提供了更好的选择。