Complex-radical terpolymerization of styrene,maleic anhydride, and N-vinyl pyrrolidone via y-ray radiation:Synthesis, characterization,and micellization

摘要

Radical terpolymerization of donor-acceptor monomers,i.e.styrene(St),maleic anhydride(MA)and N-vinyl pyrrolidone(NVP)were carried out in methyl ethyl ketone(MEK)under y-ray radiation at room temperature.Constants of copolymerization,complex formation,and some kinetic parameters for the monomer systems were studied by UV,~1H NMR,Kelen-Tudos.and Fineman-Ross methods,respectively.Obtained results show that terpolymerization proceeded mainly through 'complex' mechanisms in the state of near-binary copolymerization of St...MA and MA...NVP complexes.The homo-polymerization of St and NVP and the copolymerization between St and NVP could hardly be occurred.The possible reason is the effect of protection from radiation by styrene with its aryl-ring structure and/or the much larger reactivity of the complex copolymerization between the donor-acceptor monomers.The terpolymer self-assembles into micelles in aqueous solution.Polymeric micelles,composed of chains of St-MA and MA-NVP with equal molar ratio,displayed narrow size distribution of about 120 nm.The critical association concentration of micelles was determined to be around 3 mg/L.