RIAM, Department of Materials Science & Engineering, College of Engineering , Seoul National University , Gwanak-ro, 1 , Gwanak-gu, Seoul 08826 , Korea.
Langmuir. 2018 Sep 18;34(37):11027-11033. doi: 10.1021/acs.langmuir.8b01860. Epub 2018 Sep 5.
Dynamic secondary-ion mass spectroscopy (DSIMS) was used to investigate the change in the failure mechanism at a heterogeneous polymer-polymer interface (polystyrene (PS)/polyamide (nylon 6, Ny6)) reinforced with in situ graft copolymers produced by the reaction between Ny6 molecules and poly(styrene- co-maleic anhydride) at the interface. The variation in fracture toughness with bonding time and temperature has been explained by two different failure mechanisms: adhesive failure at the interface for short bonding times and when the bonding temperature is low and cohesive failure between chains at the interface and bulk PS for longer bonding times and when the bonding temperature is high. DSIMS results provide the direct experimental evidence that the nonreactive molecules (PS) diffuse away from the high-potential interface, which induces the cohesive failure in the bulk of the nonreactive molecules (PS) after long annealing times. The change in the adhesion strength with temperature could also cause a change in the failure mechanism. Common features of the fracture mechanisms at heterogeneous interfaces reinforced by the in situ graft copolymers are outlined, which are independent of the polymer crystallinity.
动态二次离子质谱（DSIMS）被用于研究在由原位接枝共聚物增强的异质聚合物-聚合物界面（聚苯乙烯（PS）/聚酰胺（尼龙 6，Ny6））中失效机制的变化，原位接枝共聚物是由 Ny6 分子与聚（苯乙烯-共-马来酸酐）在界面上的反应产生的。随着键合时间和温度的变化，断裂韧性的变化可以用两种不同的失效机制来解释：在短的键合时间和低的键合温度下，界面处的粘接力失效，以及在较长的键合时间和较高的键合温度下，界面和本体 PS 之间的链内聚失效。DSIMS 结果提供了直接的实验证据，证明了非反应性分子（PS）从高势能界面扩散出去，这导致了在长时间退火后非反应性分子（PS）本体中的内聚失效。随着温度的变化，粘附强度的变化也可能导致失效机制的变化。概述了由原位接枝共聚物增强的异质界面的断裂机制的共同特征，这些特征与聚合物结晶度无关。
