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The branching copolymerization of styrene with triethylene glycol dimethacrylate (tri-EGDMA) as the branching agent was carried out using atom transfer radical polymerization (ATRP) in anisole at 90 °C. The resulting copolymers were analyzed using 1H NMR and triple detection size exclusion chromatography (TD-SEC). The NMR analysis shows that the pendent vinyl groups react even in the early stages of the polymerization. Analysis of the changes in the molecular weight and polydispersity of the copolymers suggests that the reaction system contains three components: the primary chains, the slightly branched chains comprising of two primary chains, and the highly branched chains consisting of more than three primary chains. The coupling reaction mainly takes place between the primary chains, resulting in the slightly branched chains in the early stages of the reaction, the weight fraction of the branched chains and the degree of branching increase gradually with monomer conversion, highly branched chains mainly form at relatively high monomer conversions.

An approach to branched vinyl polymers through radical polymerization in the presence of 3mercaptohexyl methacrylate (MHM) as the chain transfer monomer is reported in this paper. In the case of polymerization at styrene 100 −MHM 5.0 −AIBN 2.0 , the molecular weight increased with conversion and reached a value of >7.3 × 10 5 g/mol at 99% conversion; in addition, the Zimm branching factor, g′, was less than 1 and decreased with conversion, when the formation of the branched chain and development of branching was supposed. The bridging units in the obtained polymer, generating from MHM, were cleaved to yield the primary chains. These results have confirmed the formation of branched polymers. Moreover, this study successful prepared branched poly(methyl methacrylate) and poly(vinyl acetate). This methodology proposes good prospects for scaling-up and thereby offers a wide range of branched vinyl polymers at low cost.

The process of wound healing is often accompanied by bacterial infection, which is a serious threat to human health. The abuse of antibiotics in traditional therapy aggravates the resistance of...

This paper reports a new type of click chemistry via a phosphazene bases-catalyzed oxa-Michael addition of an alcohol to an acrylate.