The aggregation structure regulation of lignin by chemical modification and its effect on the property of lignin/styrene–butadiene rubber composites

Abstract

ABSTRACTThe aggregation structure of lignin in aqueous solution had an important effect on the dispersion of lignin and the properties of lignin/styrene–butadiene rubber (SBR) composites. This article revealed the relationship between aggregation structure and chemical structure of modified lignin. Unmodified lignin was amorphous; however, our results showed that aldehyde‐modified lignin was transformed into spherical aggregates, while propylene‐oxide‐modified lignin self‐aggregated into supramolecular domains. The relationships between aggregation structure, filler dispersion, filler–rubber interaction, and performance were also studied by investigating the microstructure, viscoelastic behavior, and mechanical properties of lignin/SBR composites. Meanwhile, a solution to improve the coprecipitation efficiency of lignin and SBR latex was proposed. In this article, epoxidized natural rubber (ENR) was also used as compatibilizer to improve the interfacial adhesion between polar lignin and nonpolar SBR. The results showed better lignin dispersion for the ENR‐containing rubber composites, as well as superior wet skid resistance and lower rolling resistance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45759.