Synthesis Of Polymers With Different Topologic Structures

Topological structure plays an important role in the control of properties of polymer materials. Polymers with different topological structures, such as linear, star and comb structure, have been synthesized. Linear block copolymers, comb polymers and sing-chain nanoparticles are three different types of polymers with different topological structures. Herein, we used different polymerization methods such as RAFT,ROR, combining with different coupling chemical reactions,to synthesize linear triblock polymers with polypeptide block, polymer brushes with pendant polypeptide chains and single-chain nanoparticles. The synthesis and chaterizations of the polymers with three different structures were studied in detail.Triblock polymers with one PBLG block were successfully synthesized by the combination of reversible addition-fragmentation chain transfer polymerization (RAFT), esterification and ring opening polymerizaiton (ROP). The successful synthesis of the polymers indicates that a combination of RAFT, ROP and esterification is a highly efficient method and could be used in the synthesis of sophisticate polymers.’H NMR, GPC and TEM results indicate that the polymers with well-defined structures, narrow molecular weight distributions (Mw/Mn≤<1.46) were prepared. The triblock copolymers self-assembled into spherical micelles in water, and the size of the micelle is strongly dependant on the length of PBLG.Temperature sensitive polymer brushes with pendant polypeptide side chains poly(NIPAM-co-NAS)-graft-PBLG were successfully synthesized by the combination of reversible addition-fragmentation chain transfer polymerization (RAFT), esterification and ring opening polymerizaiton (ROP).1H NMR, CD, CPMAS and GPC results indicate that the polymer brushes with well-defined structures, narrow molecular weight distribution (Mw/Mn≤1.45) were prepared. TEM results indicate that the polymer brushes with different PBLG side chain lengths could be self-assembled into spherical, vesicle and wormlike structures in water, the morphology of the micelle was determined by the length of PBLG side chains. The poly(N-isopropyl acrylamide) backbone were temperature sensitive, and the LCST was36℃.The PBLG side-chain terminal amino groups of polymer brushes functionalized with1-Pyrenebutyric acid were successfully synthesized.1H NMR and UV-VIS results indicate that well-defined polymer were prepared, and the reaction proportion is93.2%; while TEM results indicate that the fabricating structure was transferred from spherical to vesicle.The PBLG side-chain terminal amino groups of polymer brushes functionalized with PPEGMA were successfully synthesized.1H NMR and GPC results indicate that well-defined polymer were prepared, and the reaction proportion is91%; while TEM results indicate that the fabricating structure was changed that the stability of the micelle was impoved.Single-chain nanoparticles were successfully synthesized by the combination of continuous reversible addition-fragmentation chain transfer polymerization (RAFT) and intramolecular cross-linking.1H NMR and GPC results indicate that single-chain nanoparticles were well-defined and had narrow molecular weight distribution (Mw/Mn≤1.44). TEM results indicate that single-chain nanoparticles could be self-assembly into spherical in water, while TEM results indicate that single-chain nanoparticles could be controlled by disulfide linkage switch.The preparation of thiblock polymers, polymer brushes and single-chain nanoparticles were reported that open an new avenue in synthetic methodology of polymers and guide a new direction in sophisticated polymer preparation.