다중양자 고체 핵자기공명 분광법을 이용한 탄성체 가교 밀도 정량분석 최신 연구 동향

초록

Elastomers, which achieve high durability and excellent elasticity through crosslinked network structures, are indispensable materials widely utilized across various modern industries. Since the physical properties of elastomers are closely correlated with their crosslink density, numerous measurement techniques have been developed to quantify the crosslinking structure, including the swelling method based on the Flory-Rehner equation, tensile testing using the Mooney-Rivlin model with a Universal Testing Machine (UTM), and rubber plateau region analysis via Dynamic Mechanical Analysis (DMA). However, due to the inherent heterogeneity of the actual crosslinked structures in elastomers, there remains a need for a novel analytical approach capable of not only quantifying the crosslink density but also elucidating the crosslinking distribution. In this review, we introduce double quantum nuclear magnetic resonance (DQ-NMR) spectroscopy, which detects nuclear spin signals arising from crosslink-induced double quantum coherence, as a powerful tool to evaluate both the crosslink density and its distribution in elastomers. This method enables precise quantification of the crosslink density and, through normalization,provides crosslinking distribution curves that offer deeper insights into the structuralheterogeneity of elastomeric networks. Accordingly, this review outlines thefundamental principles of DQ-NMR and highlights recent research trends employing DQNMRtechniques to characterize the crosslinking structures of elastomers.

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