New biobased carboxylic acid hardeners for epoxy resins
Résumé
Soybean oil was modified into a novel biobased polyacid hardener by thiol-ene coupling with thioglycolic acid. The structure of the initial soybean oil and polyacid triglyceride was carefully analyzed using 1H NMR and titration. The thermal crosslinking reaction between acid hardener and epoxidized resin was studied by differential scanning calorimetry (DSC) and rheology. Then, the synthesized biobased acid hardener was employed as a novel curing agent for bisphenol A diglycidyl ether to elaborate new partially biobased materials. These materials, formulated in stoichiometry ratio, were characterized by DSC, thermogravimetry analyses, dynamic mechanical analyses and exhibit interesting properties for coatings.