Cellulose/Polystyrene Composite Materials: An Effective Method With High Dispersion in <scp>PS</scp> Resin and Its Enhanced Heat Resistance

ABSTRACT Polymer composite materials are a significant category of composites, wherein the properties of the material are determined by indicators such as solid phase dispersion and interface compatibility. To address the challenge of achieving fine dispersion and interface compatibility of solid phase particles, a straightforward approach is presented, involving the modification of the surface of microcrystalline cellulose (MCC) using octadecyl amine polyoxyethylene ether‐5 oxide. These modified MCC are then dispersed in styrene and subjected to in situ emulsion polymerization. In addition to modifying the surface of MCC, octadecyl amine polyoxyethylene ether‐5 oxide not only forms micelles to maintain the emulsion polymerization system but also stabilizes the free radicals in the initiator system with its own nitrogen‐oxygen active functional groups. The thermal decomposition temperature of the composite polymer material has been significantly increased from the initial 300°C to 375°C and effectively increased the Vicat softening temperature of ABS resin blended with the modified MCC/polystyrene (modified MCC/PS) from 98°C to 101°C. Moreover, the weight‐average molecular weight of polystyrene increased to 2.55 × 10 6 due to the radical‐regulating effect of the modifier. This method provides a simple and effective strategy to achieve high dispersion of MCC and enhance the overall thermal performance of PS composites.