Effect of 3-Mercaptopropionic Acid on Polymerization of Thermo-Responsive Poly(N-Isopropylacrylamide)
Poly(N-isopropylacrylamide) (PNIPA) is a thermally sensitive polymeric material. The temperature-sensitive nature of PNIPA makes it an attractive candidate for controlled drug delivery devices. A series of temperature-responsive PNIPA were produced by fre
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Abstract Poly(N-isopropylacrylamide) (PNIPA) is a thermally sensitive polymeric material. The temperature-sensitive nature of PNIPA makes it an attractive candidate for controlled drug delivery devices. A series of temperature-responsive PNIPA were produced by free radical polymerization using various amount of 3-mercaptopropionic acid (MPA) as chain transfer agent. The effect of chain transfer agent on the lower critical solution temperature (LCST) and chemical structure of PNIPA was characterized by using UV–vis spectrophotometer and Fourier transform infrared spectroscopy (FTIR), respectively. It was found that, with increasing MPA content, the typical band of the PNIPA in respective FTIR spectrum was shorter or getting narrower due to the decrease in the strength of respective bond in the PNIPA structure. Furthermore, the increase in MPA volume in the polymerization increased the LCST of PNIPA. The various amounts of 3MPA ratios to monomer preparation have shown that hydrophobic modification of carboxylated PNIPA.
Keywords Poly N-isopropylacrylamide 3-Mercaptopropionic acid Fourier transform infrared spectometer UV–vis spectrophotometer Lowe critical solution temperature
Introduction Water-soluble polymers and hydrogels are responsive or sensitive to external stimuli like temperature, pH, ionic strength, solutes or solvent composition. These smart materials represent an important and active research area due to many D. Krishnaiah (&) S. M. Anisuzzaman S. F. Shi A. Bono Chemical Engineering Programme, School of Engineering and Information Technology, University Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia e-mail: [email protected]
R. Pogaku et al. (eds.), Developments in Sustainable Chemical and Bioprocess Technology, DOI: 10.1007/978-1-4614-6208-8_43, Springer Science+Business Media New York 2013
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possible applications in diverse technological fields (Pagonis and Bokias 2007). Due to the specific intelligent nature, ‘‘smart’’ polymers have attracted increasing interest and considerable research attention in recent years. Further researches into these polymer synthesis, behavior, and application show that these polymers have great potential to become the ‘‘next generation’’ of separation media for costeffective and environment-friendly extraction and purification of high value biomolecules from agricultural food and other raw materials (Maharjan et al. 2008). Poly(N-isopropylacrylamide) (PNIPA) is a typical thermo-sensitive polymeric material which demonstrates a transition temperature (Ttr) or lower critical solution temperature (LCST) at *32 C in aqueous solution (Zhang et al. 2002; Zhang and Zhuo 2000a). PNIPA has been studied extensively for the past 20 years due to its useful applications in many fields such as artificial muscle, on–off switches, immobilization of enzymes, thermo-sensitive absorbents, drug release, and others applications (Zhang and Zhuo 2000b). In the process to synthesis the PNIPA, free radical polymerization is a more pref
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