Synthesis And Characterization Of Amphiphilic Graft Copolymer PEO-g-PCL And PEO-g-(PCL-b-PtBA)₂

Because of the discovery and rapid development of controlled/"living" polymerizations and click reaction, a variety of complex polymers can be designed and synthesized by a combination of multiple living polymerization techniques and click reaction at the molecular level.Graft copolymers with homogenous density and length of graft chains can be synthesized by grafting from. Graft copolymers containing PEO can be widely used in the field of adhesives, anti-biological surface proteins, chromatography equipments, lubricants, surfactants polymer compatibilizing agents and so on. In this paper, we successfully synthesized graft copolymers with PEO as main chain by a "grafting from" living polymerization techniques. At the same time, we also provide a new means to synthesize polymers with complex structures. The main results are as follows:1. Amphiphilic graft copolymers PEO-g-PCL with a clear structure, molecular weight control, narrow molecular weight distribution was obtained by anionic ring-opening polymerization (AROP) and coordination-insertion ring-opening polymerization (CROP), characterization of intermediates and final products was described in detail. The relationship between critical micelle concentration and the polymer with different ratios of hydrophilic and hydrophobic chain was studied, morphology of the micelles was observed with electronic transmission electron microscop.2. In this study, A micromolecule EEGE-N3 with trifunctional groups was synthesized, a kind of novel amphiphilic graft copolymer with PEO as main chains, Y-shaped block polymers as side chain, was firstly designed and synthesized by the combination of anionic ring-opening polymerization (AROP), coordination-insertion ring-opening polymerization (CROP), click reaction and atom transfer radical polymerization (ATRP). Intermediates and final products were characterized in detail.The linear PEO with double hydroxyls pendant unit perchain was produced by anionic polymerization of ethylene oxide (EO) and ethoxyethyl glycidyl ether (EEGE) initiated by 2-(2-methoxyethoxy)ethoxide potassium first, then the hydroxyl groups on the backbone were recovered after hydrolysis, then modified by propargyl bromide, subsequently, the polymer with double hydroxyls pendant unit perchain was obtained after the azide-alkyne click reaction between alkyne-terminated PCL-co-Gly and EEGE-N3 followed by hydrolysis, PEO-g-PCL2 was synthesized via ROP. End-hydroxyls was modified by 2-bromoisobutyryl bromide to get macroinitiator bromo-functionalized PEO-g-PCL2(ATRP) to initiate butyl acrylate, subsequently, PEO-g-(PCL-b-PrtBA)2 graft copolymer with regular grafting points was obtained. Well-defined polymers were characterized by H NMR, gel permeation chromatography (GPC).