Spent coffee Grounds/Poly(butylene succinate) biocomposites with Robust mechanical property and heat resistance via reactive compatibilization

Together the use of biodegradable polymer with waste circulation is being the trend to alleviate the current environmental pollution. In this work, poly (butylene succinate) (PBS) based biocomposites containing different contents of spent coffee grounds (SCGs) were developed by reactive extrusion using polymethyl methacrylate-polyglycidyl methacrylate random (PMMA-r-PGMA) copolymer as a compatilizer. PMMA-r-PGMA copolymer was successfully synthesized by the methods of free radical polymerization in order to modify the surface of coffee oil-extracted SCGs (mSCGs). Surface treatment can effectively enhance the interfacial interaction between PBS and SCGs. It found that mSCGs may act as a nucleating agent, improving degree of crystallinity and crystallization temperature of composites. Compared with raw PBS and eSCGs/PBS composite, mechanical properties of mSCGs/PBS composites were obviously enhanced. Moreover, coefficient of thermal expansion of mSCGs/PBS biocomposites obviously declined, and heat deflection temperature of composite with the addition of 20 wt% mSCGs increased by 11 oC than that of pure PBS.