No abstract

Photo‐initiated radical polymerization has several advantages that qualify this process for application in many industrial fields, but suffers from oxygen (O2) inhibition. The prohibitive cost of existing methods to prevent O2 inhibition has hampered their widespread use in industrial applications involving free radical polymerization in air. A novel approach based on an enzymatic pathway in which glucose oxidase acts as catalyst for glucose oxidation using O2 is described to overcome O2 inhibition of radical polymerizations.

Ag‐nanoparticle‐containing hydrogels were successfully prepared by in situ reduction of silver nitrate in the presence of citrate molecules as stabilizing agent during photoinduced copolymerization of AAm and BAAm. Swelling‐deswelling behavior and thermal properties of the synthesized hydrogels were investigated. The interior morphology of the gels exhibit continuity, which is a common feature for hydrogel networks. Antimicrobial activities of the hydrogels were also investigated against pathogenic E. coli O157:H7, S. aureus, and non‐pathogenic E. coli K‐12, which are model microorganisms for testing bactericidal properties. The hydrogels containing well‐dispersed Ag NPs showed significant antibacterial activity.magnified image

Lightly branched, hyperbranched and cross-linked polymers with clickable sites were synthesized via a modified version of self-condensing photoinitiated copolymerization of methyl acrylate (MA) with propargyl acrylate (PA). The method is based on the use of a PA monomer containing two polymerizable groups, namely acrylate and propargyl groups with different reactivities in photoinitiated free radical copolymerization with MA.

A novel two-step procedure for the preparation of block copolymers by combination of atom transfer radical polymerization (ATRP) and visible light radical photopolymerization (VLRP) methods is described. In the first step of the procedure, ω-bromide functional polystyrene (PSt-Br) was synthesized by ATRP of styrene (St) in toluene at 110 °C using ethyl-2-bromopropionate and copper bromide/N,N,N 0 ,N 00 , N 00 -pentamethyldiethylenetriamine as initiator and ligand, respectively. Visible light irradiation of these polymers in the presence of dimanganese decacarbonyl [Mn 2 (CO) 10 ] produced macroradicals at ω-chain ends capable of initiating radical polymerization of various monomers, namely methyl methacrylate (MMA), butyl acrylate (BA), and vinyl acetate (VA). In this way, depending on the termination mode of the monomer involved AB or ABA type block copolymers consisting of PSt and respective segments were readily formed. The final polymers and intermediates at various stages were characterized by 1 H NMR spectroscopy and gel permeation chromatography (GPC).