The mechanical and optical properties of PMMA prepared by modified microemulsion polymerization (PMMA-MMP) have been investigated, and compared with those of PMMA prepared by bulk polymerization (PMMA-BP). The results show that PMMA-MMP possesses higher Tg, tacticity, and higher mechanical modulus in a wide temperature range than PMMA-BP. Furthermore, the tensile strength, tensile modulus and elongation at break of PMMA-MMP are higher than those of PMMA-BP. The refractive index of PMMA is little concerned with the preparation method, however, the extinction coefficient of PMMA-MMP is smaller than that of PMMA-BP, i.e. PMMA-MMP is more transparent. These results indicate that PMMA-MMP has greater potential in application.

Key words: polymethyl methacrylate, modified microemulsion polymerization, bulk polymerization, mechanical property, optical property