Hydrophobically modified microcrystalline cellulose for replacing silica in natural rubber composites

Abstract

Cellulose is a sustainable alternative to conventional inorganic fillers. However, its propensity to agglomerate hinders the advancement of natural rubber composites. To address this challenge, a novel macromolecular chain, Poly(dodecahydroxystearic acid)-3-isocyanatopropyltrimethoxysilane (PHS-IPMS), was synthesized and grafted onto the cellulose surface to confer superior hydrophobic properties. The modified cellulose-filled natural rubber composites increased the tensile strength and tear strength by 21.82% and 24.82%, respectively, up to 75% replacement of silica. Molecular dynamics simulations indicate that the macromolecular chain-modified cellulose exhibits improved dispersibility and stronger interfacial bonding with natural rubber compared to its unmodified counterpart. This work provides a novel method for cellulose modification and extends the applicability of green polymer-based materials.