文摘
We have synthesized a series of poly(4-(2-tetrahydropyranyloxy)styrene) [P(OTHPSt)] homopolymers by living anionic polymerization of the protected monomer (OTHPSt) in tetrahydrofuran at 鈭?8 掳C, with excellent control over molecular weight and dispersity. The high Tg of P(OTHPSt) led to facile purification and isolation of the polymer as a powder. Characterization of the POTHPSt homopolymer by nuclear Overhauser effect spectroscopy confirms the strong preference for the axial position of the relatively sterically demanding alkoxy phenyl group. By sequential monomer addition, a series of low to high molecular weight P(OTHPSt-b-styrene) BCPs with narrow dispersities were synthesized. Quantitative deprotection of the THP groups yielded poly(4-hydroxystyrene-b-styrene) with tunable molecular weights and compositions. The solid-state and melt-phase self-assembly of these diblocks was investigated using synchrotron small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Mean-field theory analysis of the temperature-dependent correlation-hole scattering for a disordered diblock was used to determine the interaction parameter as 蠂HS/S(T) = (4.39 卤 0.83)/T + (0.109 卤 0.002), which is approximately 4 times larger than that of poly(styrene-b-methyl methacrylate) with the same disproportionately high contribution of entropy to the free energy of mixing.