Tailoring the Swelling and Glass-Transition Temperature of Acrylonitrile/Hydroxyethyl Acrylate Copolymers

Novel polyacrylonitrile (PAN)-co-poly(hydroxyethyl acrylate) (PHEA) copolymers at three different compositions (8,12, and 16 mol % PHEA) and their homopolymers were synthesized systematically by emulsion polymerization. Their chemical structures and compositions were elucidated by Fourier transform infrared, H-1-NMR, and C-13-NMR spectroscopy. Intrinsic viscosity measurements revealed that the molecular weights of the copolymers were quite enough to form ductile films. The influence of the molar fraction of hydroxyethl acrylate on the glass-transition temperature (T-g) and mechanical properties was demonstrated by differential scanning calorimetry and tensile test results, respectively. Additionally, thermogravimetric analysis of copolymers was performed to investigate the degradation mechanism. The swelling behaviors and densities of the free-standing copolymer films were also evaluated. This study showed that one can tailor the hydrogel properties, mechanical properties, and T-g's of copolymers by changing the monomer feed ratios. On the basis of our findings, PAN-co-PHEA copolymer films could be useful for various biomaterial applications requiring good mechanical properties, such as ophthalmic and tissue engineering and also drug and hormone delivery. (C) 2009 Wiley Periodicals, Inc. J AppI Polyrn Sci 116: 628-635, 2010