Abstract：

Thermoplastic elastomers (TPEs) are materials with rubber-like properties, and have various applications in everyday life. In contrast to rubbers that achieve their elastic properties by chemical cross-links between macromolecules, TPEs become rubber-like materials by the formation of hard physical cross-links domains and soft continuous phase in a three-dimensional network. Nowadays, the commercial TPEs such as SBS and SIS are linear triblock copolymers synthesized by anionic polymerization, and then a lot of researches have been done to synthesize novel TPEs with good elastic property and mechanical properties. Inspired by the previous work that multigraft copolymers synthesized by high-vacuum anionic polymerization with polyisoprene as backbones and polystyrene as side chains could be as a sort of superelastomers, we report synthesis and characterization of multigraft copolymers with poly(n-butyl acrylate) or polyisoprene as soft backbones and polystyrene or poly(methyl methacrylate) as hard side chains by the combination of anionic polymerization and environment-friendly emulsion polymerization. Firstly, the hard macromonomers with different molecular weight were synthesized by living polymerization (high vacuum anionic polymerization and ATRP) and end-capping reaction. Secondly, the macromonomers copolymerized with the soft monomers in free radical emulsion polymerization initiated by AIBN and redox system, and the multigraft copolymers were obtained after the copolymerization. The molecular weight of macromonomers and multigraft copolymers was measured by GPC. The structure characterization of macromonomers and multigraft copolymers was investigated by NMR, MALDI-TOF and DSC. The microphase separation of multigraft copolymers was observed by AFM and TEM. The rheological property of multigraft copolymers was characterized via rheometer, and it showed that the multigraft copolymers could be a candidate of thermoplastic elastomers.
Keywords: Multigraft copolymer; Macromonomer; Living polymerization; Emulsion polymerization; Rheology

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Biography：

Pro. Zhang Qiuyu, born in October 1965, is the specialist on polymer chemistry and physics and is employed as a Yangtze river scholars Distinguished Professor in 2009. She obtained her bachelor’s degree from Beijing University of chemical Technology in 1987, master’s degree from Institute of Chemistry Chinese Academy of Science in 1990, and Ph.D from Department of Materials of Northwestern Polytechnical University in 1999. In 2000, she was appointed professor at NPU. During 2002 to 2004, as a visiting scholar and the Royal Society Chinese young scholars, she did collaborative research in the UK and mainly engaged in nanopolymer composites.
Her main research directions: (1) Control of structure and properties of micro-nano composite particles (2) Synthesis, mechanism and application of the particles with different pore sizes and pore size distribution and film; (3) controlled polymerization methods and principles; (4) organic-inorganic hybrid of polymer functional composite materials; (5) design and synthesis of new energy materials.
She won one first prize and one second prize of Shaanxi Provincial Science and Technology, a number of research awards, has published more than 150 papers and more than 10 authorized patents. And she has also won Shaanxi Provincial Youth Science and Technology Award, Ministry of Education Henry Fok Award for outstanding young teachers and many other awards.