Synthesis and characterization of cellulose-hybrid polystyrene nanoparticles by using reactive hydroxypropyl methylcellulose phthalate

Reactive hydroxypropyl methylcellulose phthalate (reactive HPMCP) was synthesized by using a stepwise urethane reaction with isophorone diisocyanate (IPDI) and 2-hydroxyethyl methacrylate (HEMA). Molecular weight, acid number, and critical micelle concentration (CMC) of the synthesized reactive HPMCP and pristine HPMCP were measured and used as a polymeric surfactant in the emulsion polymerizations of styrene. In the preparation of HPMCP-hybrid polystyrene nanoparticles, 6, 9, 12, 18, and 24 wt% of HPMCPs were introduced, and the maximum rate of polymerization (R_p,max), the average number of radicals per particle (n̄), particle size distribution were investigated. In addition, core-shell morphology of the nanoparticles were observed by using TEM and their thermal stabilities were measured by using TGA. Reactive HPMCP showed higher R_p,max, smaller particle size, larger values of n̄, and gel contents as compared with pristine HPMCP, due to the vinyl groups from HEMA, which can be reacted with styrene oligomers, in the reactive HPMCP.