| The study on poly(N-propargylamides) draws world wide attention due to the significant potential applications. We synthesized a series of (N-propargylamide) monomers with specially designed functional groups and chose monomer 1 containing cinnamamide groups for further polymerization and copolymerization with monomer 2. We investigated the mechanism of polymerization and secondary structure of poly(2). Taking the poly(2) as a representative, we investigated the photostability of poly(N-propargylamide)s under various UV irradiation conditions.Monomer 1, CH=CCH2NHCOCH=CH(C6H5), was synthesized and polymerized with a rhodium catalyst, (nbd)Rh+B-(C6H5)4 (nbd -2,5-norbornadiene). Effects of some factors on polymerization of monomer 1 such as solvent, temperature, and the ratio of monomer/catalyst were investigated in detail. To improve the polymers' solubility and to elucidate whether poly(1) could form helical conformation, another N-propargylamide monomer 2, CH≡CH2NHCOCH(CH2CH3)2, was employed to accomplish copolymerization with monomer 1.The photostability of poly(N-propargylamides) was investigated in THF taking the polymer 2 (monomer: C≡CCH2NHCOCH(C2H5)2) as a representative which could form helical conformation under appropriate conditions. The effects of several factors including the intensity of UV light, the presence of oxygen, far- and near-UV light, and temperature on the degradation behavior of poly(2) were investigated. It was found that increasing the UV light intensity accelerated the degradation. When oxygen was present, it facilitated the degradation of poly(2). Far-UV light played predominant roles in initiating the degradation of polymer main chains. Elevating temperature of the polymer solution during UV irradiation made the degradation speed up; adding photoinitiator (Irgacure 651) into the solution also prompted the degradation of the polymer.
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