Synthesis and swelling characteristics of pH and thermoresponsive interpenetrating polymer network hydrogel composed of poly(vinyl alcohol) and poly(acrylic acid)

✍ Scribed by Young Moo Lee; Su Hwi Kim; Chong Soo Cho

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 760 KB
• Volume: 62
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19961010)62:2<301::aid-app5>3.0.co;2-0

✦ Synopsis

SYNOPSIS

T h e swelling behavior of novel pH-and temperature-sensitive interpenetrating polymer networks (IPNs) composed of poly(viny1 alcohol) (PVA) and poly(acry1ic acid) (PAAc) in water was investigated. The PVA/PAAc IPN hydrogels were synthesized by UV irradiation, followed by a repetitive freezing and thawing process by which PVA hydrogel networks were formed inside of cross-linked PAAc chains. T h e swelling behaviors of these IPNs were analyzed in buffer solution at various p H and temperature ranges. Swelling ratios of all I P N s were relatively high, and they showed reasonable sensitivity t o both p H and temperature. Hydrogels showed both the positive and negative swelling behaviors depending on PAAc content. IPN46 showed the positive temperature-sensitive swelling behavior and its stepwise changes in swelling ratio was about 1.8 and 2.0 obtained between 25 and 45°C a t p H 7, and between p H 4 and 7 at 35"C, respectively. T h e positive temperature dependence is attributed to the formation and dissociation of hydrogen bonding complexes between PVA and PAAc. These I P N s are expected t o show a pH-and temperature-sensitive drug release according t o the stepwise behavior a t this temperature region. 0 1996 John Wiley & Sons, Inc