Zheng Hongbing, Yue Dongmei
Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029, China.
Polymers (Basel). 2025 Aug 28;17(17):2332. doi: 10.3390/polym17172332.
Nitrile rubber (NBR) exhibits excellent oil resistance, wear resistance, gas barrier properties, and mechanical properties. On the other hand, lignin, a by-product of the pulp and paper industry, can serve as an ideal substitute for carbon black as a reinforcing agent for rubber. However, when NBR is directly compounded with lignin, direct compounding fails to achieve the desired reinforcing effect due to poor dispersion of lignin in the NBR matrix and poor compatibility with the NBR phase. In this paper, carboxyl groups were introduced via cyano group hydrolysis. By controlling the hydrolysis time, we successfully prepared two types of carboxylated NBR with different carboxyl contents. Subsequently, the carboxylated NBR was processed into lignin/NBR composites via dry blending. The results indicated that the introduction of carboxyl groups endowed NBR with higher polarity and reactivity, significantly enhancing the interfacial compatibility between lignin and the rubber matrix. The mechanical properties of the composite were greatly improved, with the mechanical strength increasing from 4.5 MPa without carboxyl groups to 13.8 MPa with high carboxyl content. The good dispersion of lignin also significantly improved the thermal stability of the composite. The carboxylation modification strategy of NBR provides a new approach for preparing high-performance NBR/biomass composites.
丁腈橡胶（NBR）具有优异的耐油性、耐磨性、气体阻隔性能和机械性能。另一方面，木质素作为制浆造纸工业的副产品，可以作为炭黑的理想替代品，用作橡胶的增强剂。然而，当NBR与木质素直接共混时，由于木质素在NBR基体中的分散性差以及与NBR相的相容性差，直接共混无法达到预期的增强效果。本文通过氰基水解引入羧基。通过控制水解时间，成功制备了两种羧基含量不同的羧化丁腈橡胶。随后，通过干混将羧化丁腈橡胶加工成木质素/NBR复合材料。结果表明，羧基的引入赋予了NBR更高的极性和反应活性，显著增强了木质素与橡胶基体之间的界面相容性。复合材料的机械性能得到了极大的改善，机械强度从无羧基时的4.5MPa提高到高羧基含量时的13.8MPa。木质素的良好分散也显著提高了复合材料的热稳定性。NBR的羧化改性策略为制备高性能NBR/生物质复合材料提供了一种新方法。
