A method of obtaining soluble itaconic acid (IA)–ethylene glycol (EG) unsaturated polyesters was developed. The reaction between IA and EG was conducted under moderate vacuum (50—60 mmHg) at 120 °C and stopped by nearly 85% conversion to avoid crosslinking. No isomerization of itaconate to citraconate and/or mesaconate was observed. The residual double bond contained in the polyester resin showed to be highly reactive and promoted gelification after few days. Therefore copolymerization reactions of the resin with a variety of vinyl monomers proceed without radical initiator. The synthetic method was successfully applied to reactions of IA with other glycols.
ABSTRACT:We synthesized copolymers based on 2-hydroxyethylmethacrylate and N-maleoylglycine by varying the monomer feed composition. The copolymers were characterized by Fourier transform infrared spectroscopy, elemental analysis, and thermogravimetry/differential scanning calorimetry as the thermal analysis method. The thermograms showed that the polymers degraded in a single-stage process. For the hydrogels of poly(2-hydroxyethylmethacrylate) and poly(2-hydroxyethylmethacrylate-co-Nmaleoylglycine) [poly(HEMA-co-MG)], swelling behaviors were investigated by the immersion of the gels in solution at pH's of 3, 5, and 7. The swelling studies were performed with and without ionic strength. The copolymer composition had a significant effect on the equilibrium swelling behavior of poly(HEMA-co-MG). With those soluble copolymer fractions, we obtained a low conversion (Ͻ30%); the monomer reactivity ratios were estimated by the Kelen-Tü dö s linear method. The data indicated that poly(HEMAco-MG) was a random copolymer.
ABSTRACT:The free-radical copolymerization of N-maleoylglycine with hydroxymethylacrylamide was studied, with the starting monomer compositions ranging from 25 to 75 mol %. The copolymer compositions were obtained by elemental analysis from the N/C weight percentage ratio. The monomer reactivity ratios were estimated by the classical Fineman-Ross and Kelen-Tü dö s linear procedure methods. The experimental data indicated random comonomer incorporation. The thermal behavior of the copolymers was investigated with differential scanning calorimetry and thermogravimetry techniques under a nitrogen atmosphere.
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