The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 31, 2004
Filed:
Oct. 28, 2002
Jungahn Kim, Seoul, KR;
Kwang Ung Kim, Seoul, KR;
Sang Seob Kim, Seoul, KR;
Keon Hyeong Kim, Seoul, KR;
Dong-Youn Shin, Seoul, KR;
Soon-Geun Hwang, Anyang-si, KR;
Jang Seop Kim, Seoul, KR;
Other;
Abstract
The present invention relates to a process for preparing copolymer hydrogels with controlled molecular weights and having both thermo- and pH-responsive properties, wherein the process comprises the steps of (a) providing sulfonamide type styrenic or (meth)acrylamide-based monomers exhibiting different pK values; (b) providing poly(N-isopropylacrylamide) or crosslinked poly(N-isopropylacrylamide-co-methylene bisacrylamide) hydrogels having thermo-responsive properties; and (c) providing several hydrogels exhibiting pH-sensitive properties and random or block copolymerizations of the sulfonamide type styrenic or (meth)acrylamide-based monomers prepared in step (a) with N-isopropylacrylamide and/or methylene bisacrylamide monomers used in step (b) in a polar or non-polar solvent; wherein said steps (b) and (c) are carried out by controlled/living radical polymerization using alkyl halides as the initiators and the transition metals with phosphine or amine ligands as the catalysts. The present invention also relates to the copolymer hydrogels made by the aforesaid process.