PREPARATION OF A UNIFORM POLY(METHYL METHACRYLATE) MACROMONOMER AND ITS POLYMERIZATION

Syndiotactic poly(methyl methacrylate) (st-PMMA) macromonomer having m ethacryloyl end group was prepared from st-PMMA living anion and separ ated into uniform macromonomers by means of supercritical fluid chroma tography. A uniform macromonomer with the degree of polymerization of 32 was polymerized radically in benzene at 60 degrees C. The uniform d imer, trimer and tetramer of the uniform macromonomer were isolated fr om the polymerization product by means of gel-permeation chromatograph y (GPC). The intrinsic viscosity ([eta]) in tetrahydrofuran of these u niform comblike polymers was determined by GPC/differential viscometri c analysis. The plot of logarithmic [eta] against logarithmic molecula r weight indicated that the trimer and tetramer assume a little shrink ing molecular shape as compared with the unimer and dimer.