Synthesis of 1:1 alternating copolymer via ring-opening polymerization

Abstract

Part I In the study of sequence-controlled copolymers 2-phenyl-1-vinylcyclobutane(VCB-Ph) were prepared and polymerized. VCB-Ph was prepared from cinnamyl chloride with diethyl malonate and subjected to radical, Ziegler-Natta polymerization, radical copolymerization with commercial olefins. Its thermal reactions were also studied. In liquid phase thermal reactions at the high temperature 200℃, the monomer, VCB-Ph, rearranged to the 4-phenylcyclohexene. Polymers were also obtained in the thermolysis. The radical polymerizations of VCB-Ph were carried out with ditert-butylperoxide(DTBP) at 140℃, with dicumylperoxide(DCP) at 150℃ or with AIBN at 65℃. IR, $^1H-NMR$ and $^13C-NMR$ spectra of the polymers indicated that the polymerization of VCB-Ph proceeded in mixed mode (17% vinyl type, 73% 1,6 ring-opening type). The resulting polymers, containing a one-to-one alternating structure of butadiene and styrene, were rubbery and soluble in common solvents. Ziegler-Natta polymerization of VCB-Ph were also studied and the polymers were obtained tacky, semisolid polymer with intact pentent cyclobutyl groups. The copolymerization with maleic anhydride proceeded in the mixed mode of ring-opening (40%) and vinyl types. But, the copolymerization with styrene proceeded mainly in vinyl fashion (95% vinyl type of VCB-Ph). Part II Substituted trioxaspiro compounds, 2-phenyl-7-methyl-1,4,6-trioxaspiro[4,5]dec-7-ene(1,4,6-TOSDE) and 2-phenyl-7-methyl-1,3,6-trioxaspiro[4,5]dec-7-ene(1,3,6-TOSDE) were synthesized and polymerized cationically under various conditions. The structure of resulting polymers were confirmed by the IR, $^1H-NMR$ and $^13C-NMR$ spectra. The monomer, 1,4,6-TOSDE, was polymerized via pyran ring-opening only at low temperature. The polymer has a structure of head-to-head methyl vinylketone and vinyl type of 2-methylene-4-phenyl-1,3-dioxolane. When the temperature of polymerization was raised, the monomer polymerized in mixed mode. The spiro monomers inves...