title: Synthesis and characterization of hydrogels from cellulose acetate by esterification crosslinking with EDTA dianhydride.
abstract: Hydrogels were prepared from cellulose acetate with a degree substitution (DS) 2.5 dissolved in dimethylformamide by esterification crosslinking with Ethylenediaminetetraacetic dianhydride (EDTAD) catalyzed by triethylamine. Subsequent conversion of the unreacted carboxyl groups to sodium carboxylates by the addition of aqueous NaHCO3 was performed to enhance the water affinity of the gels. The absorbency of the products was strongly dependent on the amount of EDTAD that was esterified to cellulose acetate, and the highest absorbency was observed for the hydrogel composed of approximately 0.36 molecules of EDTAD per repeat unit of cellulose acetate. The hydrogels were synthesized with different degrees of crosslinking and were analyzed by IR spectral (FTIR), near infrared (NIR), thermogravimetry analysis (TG and DTG), and crosslink density evaluation by Flory-Rehner theory. The hydrogels have synthesized with molar ratios EDTAD/OH groups: [1/1], [1/2], and [0.1/1]. The capacity for water absorbency was studied and compared with the water absorbency of the CA.
authors.affiliation: Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, Minas Gerais, Brazil. Electronic address: decaosenna@hotmail.com.
authors.forename: André M
authors.initials: AM
authors.lastname: Senna
authors.affiliation: Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, Minas Gerais, Brazil. Electronic address: knovak@iceb.ufop.br.
authors.forename: Kátia Monteiro
authors.initials: KM
authors.lastname: Novack
authors.affiliation: Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, Minas Gerais, Brazil; , Universidade Federal de São Carlos, 18052-780, Sorocaba, São Paulo, Brazil. Electronic address: vagner@ufscar.br.
authors.forename: Vagner R
authors.initials: VR
authors.lastname: Botaro
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry*; D004951:Esterification; D005021:Ethylamines / Q000737:chemistry; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry*; D013818:Thermogravimetry
chemical_list: D005021:Ethylamines; D020100:Hydrogels; C005062:acetylcellulose; D002482:Cellulose; D004492:Edetic Acid; C016162:triethylamine
keywords: Cellulose acetate; EDTA dianhydride; Esterification crosslinking; Hydrogel