Study On Linear And Quadruple Star Polymers Based On N - Vinylcaprolactam

amphiphilic block copolymers can self-assemble into the micelles for drug controlled release in the selective solution, amphiphilic block copolymers have important applications in the field of biomedicine. Poly(N-vinylcaprolactam)(PNVCL) has good water-solubility, thermal responsiveness and biocompatibility, its lower critical solution temperature(LCST) is in the range of physiological temperature. Therefore, PNVCL is promosing for biomedical applications. poly(D,L-lactide) has good biocompatibility and biodegradability. Thus, the block copolymer of PNVCL and PDLLA have thermal responsiveness and biodegradability via combination of the excellent properties of the PNVCL and PDLLA.In this thesis, Synthesized of different block ratio of liner amphiphilic block copolymers( PDLLA-b-PNVCL) and different block ratio of four-arms star amphiphilic block copolymers(S-PDLLA-b-PNVCL) via the combination of ROP and RAFT, among of these synthesized polymer, liner chain transfer agent, star chain transfer agent and three star block copolymer is new polymeric compound. The structure of polymer was characterized by 1H NMR and IR spectra, and the molecular weight and PDI of the polymer was determined by GPC-MALLS. Their thermoresponsive properties, self-assembling behaviors in aqueous solution and the drug controlled release were studied.The results showed that the LCST of the copolymer is reduce with the increase of the block ratio of the PDLLA and the increase of the concentration of the copolymer. The amphiphilic block copolymers can self-assemble into the micelles. The drug loading capacity of micelles of the copolymers is excellent for naproxen, used as a model drug. The drug release was faster above the LCST than below the LCST.