Polymers having the structure of phosphine oxide have properties such as biocompatibility, metal coordination, flame retardancy, proton conductivity and the like. Therefore, it is applied to drug transport, coating agent, fuel cell membrane, flame retardant and the like. Many polymers with current phosphine oxide have a conjugated substituent spacer interposed between them and the main chain. However, as the side chain becomes longer, the decomposability increases and the heat resistance is affected. Further, the structure directly bonded to the main chain is unstable and can’t obtain a polymer. Therefore, we studied the polymerization of two types of monomers, Dimethyl vinylphosphonate and Vinylphosphonic acid, without a spacer.
In both cases, there are few examples synthesized by radical polymerization, and for Dimethyl vinyl phosphonate, there is only an example of synthesis by coordination polymerization using a lanthanoid type catalyst. Various additives including dissolving Dimethyl vinylphosphonate, water, methanol and toluene as solvents, and Lewis acids effective for radical polymerization were used. Polymerization did not proceed. Synthesis of Dimethyl vinylphosphonate by free radical polymerization was very difficult. Radical polymerization of Vinylphosphonic acid without methyl group cap was carried out to investigate the difference in behavior of polymerization. It has been found that radical polymerization proceeds through an anhydride. Based on this result, we decided to examine the radical polymerizability of Dimethyl vinylphosphonate once again. Both Dimethyl vinylphosphonate and Vinylphosphonic acid can be said to have low radical polymerizability. However, Vinylphosphonic acid was found to promote polymerization by the cyclization polymerization mechanism by anhydride. Therefore, we reexamined the radical polymerizability of Dimethyl vinylphosphonate and decided to approach by copolymerization. It was found that Vinylphosphonic acid has a high glass transition temperature and that the copolymer also has a relatively high glass transition temperature between 100 ° C and 200 ° C. Furthermore, it can be said that introduction of Dimethyl vinylphosphonate could be confirmed also from the fact that the glass transition temperature of the copolymer exists between Dimethyl vinylphosphonate and Vinylphosphonic acid.
As a result, Dimethyl vinylphosphonate without radical polymerizability was copolymerizable with Vinylphosphonic acid, and a polymer with a molecular weight exceeding 100,000 was obtained. On the basis of the above, it is possible to synthesize a functional polymer by copolymerizing with a nonconjugated monomer, and it is expected that homopolymerization of Dimethyl vinylphosphonate with a chain transfer agent is possible.
In both cases, there are few examples synthesized by radical polymerization, and for Dimethyl vinyl phosphonate, there is only an example of synthesis by coordination polymerization using a lanthanoid type catalyst. Various additives including dissolving Dimethyl vinylphosphonate, water, methanol and toluene as solvents, and Lewis acids effective for radical polymerization were used. Polymerization did not proceed. Synthesis of Dimethyl vinylphosphonate by free radical polymerization was very difficult. Radical polymerization of Vinylphosphonic acid without methyl group cap was carried out to investigate the difference in behavior of polymerization. It has been found that radical polymerization proceeds through an anhydride. Based on this result, we decided to examine the radical polymerizability of Dimethyl vinylphosphonate once again. Both Dimethyl vinylphosphonate and Vinylphosphonic acid can be said to have low radical polymerizability. However, Vinylphosphonic acid was found to promote polymerization by the cyclization polymerization mechanism by anhydride. Therefore, we reexamined the radical polymerizability of Dimethyl vinylphosphonate and decided to approach by copolymerization. It was found that Vinylphosphonic acid has a high glass transition temperature and that the copolymer also has a relatively high glass transition temperature between 100 ° C and 200 ° C. Furthermore, it can be said that introduction of Dimethyl vinylphosphonate could be confirmed also from the fact that the glass transition temperature of the copolymer exists between Dimethyl vinylphosphonate and Vinylphosphonic acid.
As a result, Dimethyl vinylphosphonate without radical polymerizability was copolymerizable with Vinylphosphonic acid, and a polymer with a molecular weight exceeding 100,000 was obtained. On the basis of the above, it is possible to synthesize a functional polymer by copolymerizing with a nonconjugated monomer, and it is expected that homopolymerization of Dimethyl vinylphosphonate with a chain transfer agent is possible.