Synthesis, hydrophilicity, and oxygen permeability of poly [(trimethylsilyl) propyne]-gr-poly (N,N-dimethylacrylamide)

Abstract

N,N-dimethylacrylamide (DMAA) was graft copolymerized on poly[(trimethylsilyl)propyne] (PTMSP) by single electron reduction of PTMSP with potassium naphthalenide (K-Naph), followed by anion polymerization of DMAA from the carbanion formed in the reduction. A hard and practically non-water-swelling PTMSP-gr-poly(DMAA) was obtained under the conditions using controlled amount of K-Naph and DMAA. The graft copolymer was characterized with regard to structure, number-averaged molecular weight, and the amount of grafting poly (DMAA) determined by the relative absorbance of the IR absorption band assigned to the C=O and SiC - H functionalities (AC=O/ASiC - H). The oxygen permeability and water contact angle (θ) of the graft copolymer were evaluated while varying the amount of grafting poly (D-MAA). The graft copolymer proved to be highly oxygen permeable (165 Barrers) and hydrophilic (θ = 27°). Its transparency was also elucidated with UV-vis spectra. This graft copolymer was proposed as a promising candidate for use as a hard contact lens material. © 1998 John Wiley & Sons, Inc.