Extraction of microcrystalline cellulose from cotton fiber, and application to block natural rubber as reinforcing agent

Abstract

Crosslinked natural rubber (NR)/microcrystalline cellulose (MCC) composite was prepared by dry mixing of NR with MCC extracted from cotton fiber. MCC was first extracted from cotton fiber by acid hydrolysis processing, then applied to block natural rubber as a reinforcement. MCC grafted maleic anhydride (MA) was also synthesized and applied to the composites to improve the compatibility between natural rubber and cellulose. Obtained cellulose samples were subjected to infrared spectroscopy (FTIR) to confirm the purity of cellulose structure and the presence of MA grafted on MCC chains. X-ray spectroscopy (XRD) and thermogravimetric analysis (TGA) were investigated as well to see if there was any important change after modification. NR containing microcrystalline cellulose was formulated with vulcanizing agents and microcrystalline cellulose grafted MA for characterization. Micro-scale dispersion of microcrystalline cellulose was observed by scanning electron microscopy (SEM). MCC showed positive contributions to tensile strength and thermal properties of composites as well. Mechanical properties of vulcanized rubber containing microcrystalline cellulose grafted MA gave a slightly better value compared to the reference sample without adding of the compatible agent. The presence of reinforcements helped NR composites to reduce solvent uptake, however there was no change in tensile strength after aging test.