Investigation on the reaction between polyhexamethylene guanidine hydrochloride oligomer and glycidyl methacrylate

Polyhexamethylene guanidine hydrochloride (PHMG) oligomer is attracting increasing attention for its highly efficient biocidal activity and nontoxicity. To make it bearing carbon-to-carbon double bonds and enlarge its application in production of antimicrobial materials via copolymerization, PHMG oligomer was modified via reaction with glycidyl methacrylate (GMA). The influence of reaction parameters on the conversion rate of GMA was investigated using ultraviolet absorption spectroscopy. The structures of PHMG oligomer before and after modification were characterized by Fourier transform infrared spectrometry, Raman spectrometry, nuclear magnetic resonance spectrometry, and electrospray ionization time-of-flight mass spectrometry. The results show that carbon-to-carbon double bond is successfully introduced into the modified PHMG oligomer. At a feeding molar ratio of GMA to PHMG of 1.0, the conversion rate of GMA reached up to 75% after 60 h of reaction at 60 degrees C in dimethyl sulfoxide. Also, there is an activity difference in the different aminos of PHMG oligomer: the primary amino is ready to react with epoxy of GMA, while the guanidyl amino hardly reacts with GMA due to the p-p conjugation. Furthermore, the modified PHMG oligomer was used as comonomer to synthesize acrylonitrile copolymer, showing excellent antimicrobial activity against Staphylococcus aureus. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012