Interfacial crystals morphology modification in cellulose fiber/polypropylene composite by mechanochemical method

Abstract The insufficient interfacial bonding and low toughness of cellulosic fiber reinforced polypropylene (PP) composite remain limitations for advanced applications of the composite. Here we proposed to promote the interfacial adhesion by modifying the interfacial matrix crystal type and morphology, inducing the small β -PP spherulite from the dominated α-PP. Specifically, cellulose fiber was subjected to mechanical milling to improve the accessibility of hydroxyl groups, then pimelic acid, calcium carbonate and activated cellulose particles were mechanochemically reacted during solvent-free ball milling condition to prepare cellulose fillers with β nucleating sites for PP reinforcement. The nucleating effect and tensile properties of the composite were investigated. The results showed that the modified particles were effective for producing a large percentage of β crystals with smaller and more uniform spherulite, and the induced β phase crystal increased the tensile strength and elongation at break of the composite.