Improving the compatibility, surface strength, and dimensional stability of cellulosic fibers using glycidyl methacrylate grafting

The graft copolymerization of lignocellulosic fibers with glycidyl methacrylate (GMA) using a Fe 2+ –thiourea dioxide–H 2 O 2 redox system (Fe 2+ –TD–H 2 O 2 ) was studied to overcome the problems of poor compatibility and low surface strength when cellulosic fibers are composited with synthetic polymers. The results show that cellulose–poly(GMA) (CPGMA) was successfully synthesized from GMA and bleached Eucalyptus cellulosic fibers by Fe 2+ –TD–H 2 O 2 in a mild aqueous solution. CPGMA had high graft rate (244%), high content of epoxy group, and high stability in water. X-ray diffraction patterns and 13 C cross-polarization magic angle spinning nuclear magnetic resonance spectra analyses showed that graft copolymerization did not change the crystalline structure of the CPGMA fiber backbone cellulose, but the crystallinity of the CPGMA fiber decreased with an increase in amorphous PGMA grafting. Scanning electron microscopy confirmed that the grafting reaction occurred both inside and outside the fiber. The specific surface area and pore diameter of the grafted fibers were significantly affected by the grafting. The hydrophobicity of the fibers was significantly enhanced by graft copolymerization. PGMA grafting can enhance the compatibility between the modified fiber and synthetic polymer matrix, improving the processing runnability and product properties of composite materials. A high intensity focused ultrasound method was used to analyze the fiber surface strength. It was confirmed that graft copolymerization significantly improved the surface strength of the grafted fibers. Graft copolymerization can significantly improve the dimensional stability of cellulosic fibers. Graphic abstract