The visual observations of the films prepared at 25◦C, 50◦C,75◦C or 100◦C showed significant differences in the texture and slight differences in the their color. Films cured at temperature shigher than 25◦C appeared a gradual stiffness and rigidity and a pale yellow hale. The FT–IR of films showed also significant differences. These results indicate that during curing at 50◦C, 75◦Cor 100◦C side reactions also take place resulting to the forma-tion of –CHO and –C O groups through isomerization of oxiranering, but also to the formation of O–C C due to dehydration reac-tions. Irradiation of the films with light = 254 nm has detrimental effect on their structure especially of those cured at higher temperatures than 25◦C mainly at 100◦C. Irradiation caused a change in their initial flexibility and the color and the FT–IR spectrum;these changes are due to various photo-oxidation reactions. Irradiation of the films with light > 300 nm has less effect on theircharacteristics. Films cured at 25◦C, initially colorless and flexible,maintained these characteristics even after three weeks of irra-diation with light > 300 nm. Films cured at 50◦C initially alsoflexible and colorless turned slightly beige after 21 days of irra-diation and became a little bit stiffer. The FT–IR spectra of thesefilms showed that photo-oxidation reactions took also place dur-ing this irradiation. The general conclusion of this study is thatthe best temperature for curing of Hxtal NYL-1TMis that of 25◦Cand that irradiation even with light > 300 nm must be avoidedbecause may cause photo-oxidative reactions over time expo-sure. Further research on colour change of the adhesive underthe similar experimental conditions would also be interesting anduseful