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Title: Synthesis of poly(N-isopropylacrylamide) hydrogels by radiation polymerization and cross-linking

Abstract

Poly(N-isopropylacrylamide) [poly(NIPAAm)] shows a typical thermal reversibility of phase transition in aqueous solutions. That is, it precipitates from solution above a critical temperature called the lower critical solution temperature (LCST) and dissolves below this temperature. When it is cross-linked, the obtained hydrogel collapses above LCST, while it swells and expands below LCST. This hydrogel has received much attention recently and has been used as a model system to demonstrate the validity of theories describing the coil-globule transition, swelling of networks, and folding and unfolding of biopolymers. It has also been proposed for various applications ranging from controlled drug delivery to solute separation. Poly(NIPAAm) hydrogel is usually synthesized at room temperature from an aqueous solution of the monomer by using a redox initiator composed of ammonium persulfate and N,N,N{prime},N{prime}-tetramethylethylenediamine in the presence of N,N{prime}-methylenebisacrylamide as a cross-linker. Since the LCST of poly(NIPAAm) is around 32 C, the polymerization at room temperature proceeds in a homogeneous solution. Recently, poly(NIPAAm) hydrogels were synthesized by starting the polymerization below the LCST and then elevating the temperature above it, by which method macroporous gels with fast temperature response were obtained. The idea is to apply a radiation--induced polymerization method for the synthesis of poly(NIPAAm) hydrogels.more » This method offers unique advantages for synthesis: it is a simple and additive-free process at all temperatures, and the degree of cross-linking can be easily controlled by irradiation conditions. Therefore, radiation methods are especially attractive for the synthesis of hydrogels with potential biomedical application where the residual chemical initiators may contaminate the product. It is possible to combine into one step the synthesis and sterilization of the product, and it is economically competitive.« less

Authors:
; ;  [1]; ; ;  [2]
  1. Gunma Univ. (Japan). Dept. of Chemistry
  2. Japan Atomic Energy Research Inst., Gunma (Japan). Dept. of Material Development
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
142105
Resource Type:
Journal Article
Journal Name:
Macromolecules
Additional Journal Information:
Journal Volume: 26; Journal Issue: 26; Other Information: PBD: 20 Dec 1993
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; HYDROPHYLIC POLYMERS; CHEMICAL PREPARATION; RADIATION CURING; CROSS-LINKING; AQUEOUS SOLUTIONS; PHASE TRANSFORMATIONS; CRITICAL TEMPERATURE

Citation Formats

Nagaoka, Noriyasu, Kubota, Hitoshi, Katakai, Ryoichi, Safranj, Agneza, Yoshida, Masaru, and Omichi, Hideki. Synthesis of poly(N-isopropylacrylamide) hydrogels by radiation polymerization and cross-linking. United States: N. p., 1993. Web. doi:10.1021/ma00078a046.
Nagaoka, Noriyasu, Kubota, Hitoshi, Katakai, Ryoichi, Safranj, Agneza, Yoshida, Masaru, & Omichi, Hideki. Synthesis of poly(N-isopropylacrylamide) hydrogels by radiation polymerization and cross-linking. United States. doi:10.1021/ma00078a046.
Nagaoka, Noriyasu, Kubota, Hitoshi, Katakai, Ryoichi, Safranj, Agneza, Yoshida, Masaru, and Omichi, Hideki. Mon . "Synthesis of poly(N-isopropylacrylamide) hydrogels by radiation polymerization and cross-linking". United States. doi:10.1021/ma00078a046.
@article{osti_142105,
title = {Synthesis of poly(N-isopropylacrylamide) hydrogels by radiation polymerization and cross-linking},
author = {Nagaoka, Noriyasu and Kubota, Hitoshi and Katakai, Ryoichi and Safranj, Agneza and Yoshida, Masaru and Omichi, Hideki},
abstractNote = {Poly(N-isopropylacrylamide) [poly(NIPAAm)] shows a typical thermal reversibility of phase transition in aqueous solutions. That is, it precipitates from solution above a critical temperature called the lower critical solution temperature (LCST) and dissolves below this temperature. When it is cross-linked, the obtained hydrogel collapses above LCST, while it swells and expands below LCST. This hydrogel has received much attention recently and has been used as a model system to demonstrate the validity of theories describing the coil-globule transition, swelling of networks, and folding and unfolding of biopolymers. It has also been proposed for various applications ranging from controlled drug delivery to solute separation. Poly(NIPAAm) hydrogel is usually synthesized at room temperature from an aqueous solution of the monomer by using a redox initiator composed of ammonium persulfate and N,N,N{prime},N{prime}-tetramethylethylenediamine in the presence of N,N{prime}-methylenebisacrylamide as a cross-linker. Since the LCST of poly(NIPAAm) is around 32 C, the polymerization at room temperature proceeds in a homogeneous solution. Recently, poly(NIPAAm) hydrogels were synthesized by starting the polymerization below the LCST and then elevating the temperature above it, by which method macroporous gels with fast temperature response were obtained. The idea is to apply a radiation--induced polymerization method for the synthesis of poly(NIPAAm) hydrogels. This method offers unique advantages for synthesis: it is a simple and additive-free process at all temperatures, and the degree of cross-linking can be easily controlled by irradiation conditions. Therefore, radiation methods are especially attractive for the synthesis of hydrogels with potential biomedical application where the residual chemical initiators may contaminate the product. It is possible to combine into one step the synthesis and sterilization of the product, and it is economically competitive.},
doi = {10.1021/ma00078a046},
journal = {Macromolecules},
number = 26,
volume = 26,
place = {United States},
year = {1993},
month = {12}
}