In this study, the effect of alkaline-treated spent coffee grounds and compatibilizer on the mechanical properties of bio-composite based on polypropylene (PP) matrix was investigated. After alkaline treatment, the surface of spent coffee grounds became rougher; hence the PP matrix could better adsorb and encapsulate the treated coffee grounds compared with that of untreated ones. T | Cite this paper Vietnam J. Chem. 2023 61 S3 148-153 Research Article DOI Effect of alkaline-treated spent coffee grounds and compatibilizer on the mechanical properties of bio-composite based on polypropylene matrix Nguyen Ngoc Thanh1 Vu Minh Tan1 Dang Huu Trung1 Pham Thi Mai Huong1 Le Thi Hong Nhung1 Nguyen Manh Ha1 Ngo Thuy Van1 Nguyen Thanh Tung2 Nguyen Thi Thu Thuy3 1 Faculty of Chemical Technology Hanoi University of Industry Bac Tu Liem District Hanoi 10000 Viet Nam 2 Institute of Chemistry Vietnam Academy of Science and Technology Cau Giay Hanoi 10072 Viet Nam 3 Phenikaa University Nano Institute PHENA Phenikaa University Hanoi 12116 Viet Nam Submitted February 18 2023 Revised June 28 2023 Accepted August 6 2023 Abstract In this study the effect of alkaline-treated spent coffee grounds and compatibilizer on the mechanical properties of bio-composite based on polypropylene PP matrix was investigated. After alkaline treatment the surface of spent coffee grounds became rougher hence the PP matrix could better adsorb and encapsulate the treated coffee grounds compared with that of untreated ones. The TGA analysis shows that the alkaline treated spent coffee grounds had better thermal properties than the untreated ones. When increasing the weight percentage of spent coffee grounds from 10 to 20 the tensile strength and flexural strength of PP-based composite decreased. These mechanical properties of PP-based composite containing treated coffee grounds were enhanced compared with that containing untreated coffee grounds due to the better dispersion of treated coffee grounds into the PP matrix. The presence of polypropylene-graft-maleic anhydride PP-g-MA compatibilizer at the content of 1 3 and 5 wt led to a significant increase the mechanical properties of PP-based bio-composites reaching the highest tensile strength of MPa and flexural strength of MPa. Therefore the alkaline-treated spent coffee ground is a potential additive for
