title: Synthesis and characterization of hydrogels formed from a glycidyl methacrylate derivative of galactomannan.
abstract: The present investigation describes a procedure for the synthesis of a glycidyl methacrylated derivative from galactomannan, GA-MA, and the respective hydrogel formation. The galactomannan (GA), raw material, was purified and dissolved in DMSO. After dissolution, 4-dimethyl-amino-pyridine (DMAP) and glycidyl methacrylate (GMA) were added. The modified polymer, quoted as GA-MA, was purified by precipitation in ethanol. Hydrogels were obtained from GA-MA in aqueous solution by polymerization of GA-MA using sodium persulfate (SP), as initiator, and N,N,N',N'-tetramethylethylenediamine (TEMED), as catalyst. For this, the cross-linking process was trigged by the addition of TEMED and sodium persulfate aqueous solutions. Two different concentrations of TEMED and SP were used. GA, GMA and GA-MA were characterized by FT-IR and NMR (13C and 1H) spectroscopy. The addition of GMA on GA molecules was confirmed through FT-IR results by appearing of a band at nu=1717cm(-1) and also by the cleavage of Cz.dbnd6;C groups of GA-MA (band at nu=1636cm(-1)) during the cross-linking process. The signals attributed to vinyl carbon of methacrylate (delta 138.52, 130.06ppm), to carbonyl (delta 171.87ppm) and to methyl group (delta 20.19ppm) were observed in the 13C NMR spectra of GA-MA. The addition of methacrylate on GA was also confirmed through the signals present in 1H NMR spectra of GA-MA. The formation of hydrogel was observed by complete gelation. The hydrogels were characterized by FT-IR and by measuring the equilibrium water content (EWC) in pH=7.0 and 1.0. The hydrogels contain 83wt.% of water at 25 degrees C and 85wt.% at 37 degrees C. Good resistance to degradation in acidic conditions, pH=1.0, was observed at 37 degrees C up to 48h. These properties suggest that the GA-MA hydrogels may be a new material for pharmaceutical use, mainly for drug delivery system.
authors: Chemistry Department, Universidade Estadual de Maringá (UEM), Av. Colombo, 5790 Code 87020-900, Maringá, Paraná, Brazil.
authors: Adriano V
authors: AV
authors: Reis
authors: Osvaldo A
authors: OA
authors: Cavalcanti
authors: Adley F
authors: AF
authors: Rubira
authors: Edvani C
authors: EC
authors: Muniz
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D016503:Drug Delivery Systems; D004852:Epoxy Compounds / Q000737:chemistry*; D005029:Ethylenediamines / Q000737:chemistry; D005690:Galactose / Q000031:analogs & derivatives; D006358:Hot Temperature; D020100:Hydrogels / Q000138:chemical synthesis*; D006859:Hydrogen / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods; D008351:Mannans / Q000737:chemistry*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation; D013997:Time Factors
chemical_list: D004852:Epoxy Compounds; D005029:Ethylenediamines; D020100:Hydrogels; D008351:Mannans; D008689:Methacrylates; D011108:Polymers; C005798:N,N,N',N'-tetramethylethylenediamine; C012990:galactomannan; D011092:Polyethylene Glycols; D006859:Hydrogen; C007870:glycidyl methacrylate; D005690:Galactose