Influence of the black seed oil modified epoxy resin/biscycloaliphatic epoxide monomer weight ratio on thermal properties of photocrosslinked coatings

AbstractThe influence of the black seed oil modified epoxy resin (EBSO)/monomer 3,4‐epoxycyclohexylmethyl 3,4‐epoxycyclohexane carboxylate (BCDE) weight ratio in the coatings based on the compounds and photoinitiator triarylsulfonium hexafluoroantimonate (TAS) on thermal properties of photocrosslinked coatings have been studied. The chemical structure of investigated UV‐cured coatings was characterized by IR spectrometric analysis. Their thermogravimetric (TG) and differential scanning calorimetry (DSC) behavior were determined by TG and DSC analysis, respectively. It was shown that the testing atmosphere had almost no effect to the form of TG, DTG curves and little effect on value of weight degradation of investigated coatings. The volatilization of low molecular weight compounds was observed in the range from room temperature to 360oC while the thermal degradation of the coatings occurred in the range from 360 to 455.5oC. The augmentation of the EBSO/BCDE weight ratio from 20/80 to 80/20 led to an increase of the degradation temperatures in the nitrogen atmosphere; extreme character of weight loss variation as well as the reduction of glass transition temperatures of the coatings from 79.8oC (Tg1) and 83oC (Tg2) to 36.8 (Tg1) and 38.9oC (Tg2), correspondingly.