Interface has been long time recognized as crucial for changing and optimizing mechanical properties of polymer composites and nanocomposites. Spectroscopic identification of this interface, however, remains a great challenge. This study combining solid-state ¹³C NMR spectroscopy with a principal component analysis (PCA) proposes a novel strategy to explore the role of interfacial area at vicinity of filler particles on toughness of polymer composites. Samples of commercial-grade isotactic polypropylene (PP), both neat and modified with various types of calcium carbonate (CaCO₃) microparticles, were subjected to a combination of fracture mechanical testing and solid-state NMR analysis. Temperature-induced transformation between the free and constrained amorphous phases was monitored using the factor analysis of ¹³C MAS NMR spectra. The three-dimensional correlation plots clearly separated the prepared PP/CaCO₃ microcomposites into the well-defined clusters, allowing the systems with differing quantities of partially ordered amorphous domains to be identified. These differences perfectly correlated with the toughness of the prepared composites. The results thus confirmed that the changes in the toughness of the microcomposites are closely related to the increased formation of the partially ordered trans-crystalline fraction of PP chains.

长期以来，人们一直认为界面对于改变和优化聚合物复合材料和纳米复合材料的机械性能至关重要。然而，该界面的光谱识别仍然是巨大的挑战。这项研究结合了固态¹³ C NMR光谱和主成分分析（PCA），提出了一种新颖的策略来探索填料颗粒附近的界面面积对聚合物复合材料韧性的作用。纯净的并用各种类型的碳酸钙（CaCO ₃改性）的商业级等规聚丙烯（PP）样品）微粒进行断裂力学测试和固态NMR分析相结合。使用¹³ C MAS NMR光谱的因子分析监测自由和约束非晶相之间的温度诱导转变。三维相关图清楚地将制备的PP / CaCO ₃微复合物分成了明确定义的簇，从而可以识别具有不同数量的部分有序无定形域的系统。这些差异与所制备的复合材料的韧性完全相关。因此，结果证实了微复合材料的韧性变化与部分有序反式的增加形成密切相关。PP链的结晶部分。