Preparation of Partially Deuterium-labeled Poly(4-trimethylsilylstyrene)s and Unperturbed Dimensions in Bulk

Monodisperse poly(4-timethylsilylstyrene)s (PTMSS's) and the partially deuterium-labeled polymers were prepared and characterized to determine their unperturbed dimensions hy measuring small-angle neutron scattering of their blends. For polymer pairs with three different molecular weight (M w ), the radii of gyration (R g ) in bulk were estimated and a power law was deduced as R g = 0.022M w 0.50 (nm). The power index 0.50 was consistent with the theoretical prediction for ideal chains, 1/2. Although the prefactor, 0.022, is apparently smaller than that of polystyrene (PS), 0.0275, the segment length of this polymer, 0.72 nm, is similar to that of PS, 0.69 nm. It is indicated that the bulky trimethylsilyl group on 4-position does not affect much on the chain conformation of polystyrene hackbone.