Enhancing crystallization, miscibility, and processability of bio‐based polybutylene succinate/polypropylene blended composites via coffee husk reinforcement

Many studies have suggested that the interfacial compatibility in blends play an important role in determining the overall properties of the corresponding composites. This study investigated the effects of blend miscibility on the rheological, mechanical, and crystallization properties of polybutylene succinate (PBS)‐based composites reinforced with coffee husk (CH). The composites were fabricated using surface‐treated CH that was treated with a compatibilizer prior to composite fabrication. The results showed that the handling and processability of the composites improved after the surface treatment of CH. The surface treatment helped to achieve miscibility in polymer blends, and the dispersion of the surface‐treated CH in the PBS matrix was uniform. Moreover, the tensile strength and modulus of the compatibilized composites showed fourfold and twofold increases compared to neat PBS. The frequency‐dependent rheological test revealed increase in viscosity (>1000 times) and storage modulus with compatibilization and filler reinforcement. The degree of crystallinity of the PBS in the compatibilized composites reduced to about 10%. Furthermore, the compatibilized composites also demonstrated superior thermal stability than their corresponding non‐compatibilized composites.