Synthesis of Poly (Styrene-Block-Vinyl Alcohol) by Successive Photo-Induced Charge Transfer Polymerization and Molecular Dynamics Simulation of Its Compatibility for the Blend System

In the present work, a rapid and novel route to prepare a diblock copolymer consisting of styrene and vinyl acetate (VAC) units was performed by successive photoinduced charge-transfer polymerization (CTP) under UV irradiation, and then a series of objective products PS_m-b-PVA_n bearing different ratios of PS and PVA was obtained by the hydrolysis of PS_m-b-PVAC_n with sodium ethoxide as the catalyst. Additionally, the influences of the reaction time, concentration of monomer and photoinitiator and kinetics of copolymerization were investigated. Good linear relationships of ln([St] ₀/[St]) and ln([VAc]₀/[VAc]) with the polymerization time indicated a first-order control/‘living’ process. The copolymers were characterized in detail by means of Fourier transform infrared (IR) spectrometry, ¹H NMR and gel permeation chromatography (GPC). Furthermore, the miscibility of the originally incompatible blend system was improved quite significantly, so a full atomistic molecular dynamics simulation was applied to discuss the binary and ternary systems through the Flory-Huggins parameters, enthalpy of mixing and T_g.