We synthesized the novel ethane initiator, bis(2-hydroxy -1,1-diphenyl ethane) and investigated its initiating characteristics in radical polymerization. In the polymerization of styrene(St), the polymerization rate was proportional to the $0.84^{th}$ power of the initiator concentration. With MMA it was $0.69^{th}$ power. This result suggests that St shows more effective reversible termination than MMA. We have also investigated the polymerization rate, activation energy of polymerization, and changes in molecular weight. St, MMA and butyl acrylate(BA) polymerized but VAc did not. In the polymerization of St and MMA, bimodal distributions of molecular weights were observed and confirming the characteristics of 'living' radical polymerization. We synthesized the prepolymers of low molecular weight by monomer feeding method.
α, ω - Hydroxy-terminated vinyl polymers were synthesized in the presence of a two-component iniferter consisted of an initiator and a chain transfer agent bearing the same functional group. 4,4'-Azobiscyanopropanol(ACPROL) and allyl alcohol(AA) were used as initiator and chain transfer agent respectively, to synthesize the polymers having hydroxyl group at both chain ends. The butyl acrylate prepolymer of molecular weight 3,100 and functionality 2.2 was prepared by the following condition; [BA]=3.85mol/L, [ACPROL]= 0.128mol/L and [AA]=0.90mol/L at 110℃. The produced butyl acrylate has the following properties; viscosity at 75℃=579cps, Tg=-45.8℃.
The polyurethane reaction of the resulting telechelic polymers with MDI was carried out to obtain vinyl polymer-based polyurethanes. In case of poly(BA), the modulus were 46.9kgf/㎠, tensile strength at break 31.7kgf/㎠, and elongation at break were 226%. From these result, these telechelic polymers can serve as prepolymers for a variety of modifications like the synthesis of vinyl prepolymer-based polyurethane block copolymers.
