An investigation into novel multifunctional cross-linkers effect on microgel prepared by precipitation polymerization

摘要

Novel microgels composed of acrylaic acid and multifunctional cross-linkers, acrylate/methacrylate cross-linkers, were synthesized via thermal initiated free radical precipitation polymerization in organic solvents. The effect of cross-linker functionality on the properties of microgels was investigated. Results showed both the solvent absorbency and apparent viscosity depend on the network structure, the cross-linker functionality and number of hydrophobic groups. Gel content indicated more reactivity of acrylate than methacrylate cross-linkers. A linear relation exists between elastic modulus (C) and functionality (f). Also the results suggested an equation that confirmed a direct relationship between glass transition temperature (T_g) and (f). The rotational and apparent viscosity results supported the thickening properties of the microgels. Based on the observations, it is concluded that trifunctional AC cross-linker (TMPTA) choose as an improvement of thickening properties over another cross-linkers.