Radiation miniemulsion polymerization system with HTPB or its derivative as the costabilizer

Miniemulsion polymerization of styrene (St) with hydroxyl-terminated polybutadiene (HTPB) or its derivative polyurethane (HPU) acting as the sole costabilizer was successfully initiated by γ-ray radiation at room temperature. Results indicated that HTPB was more efficient than its derivative HPU in retarding the diffusional degradation of monomer droplets to realize almost complete droplet nucleation. Moreover, the effects of various reaction parameters on the polymerization kinetic and the nucleation mechanism were also investigated. It was shown that the polymerization rate indicated little dependence on [HTPB] but decreased with [HPU]. Increasing the concentration of sodium dodecyl sulfate and St and the radiation dose rate would promote the polymerization in both systems.