THERMAL CHARACTERIZATION OF RADIATION-CURED POLYMER-FILMS

Thermo-oxidative and thermo-mechanical stabilities of radiation-cured acrylates and epoxides were examined by TG, DMA and DSC. The polymeric trifunctional acrylates PETIA, TMPTA and THEIC displayed the highest temperatures of onset of degradation. The high crosslinking density of the films resulted in an almost temperature-independent complex E-mod ulus, as measured by DMA. With increasing degree of ethoxylation or pr opoxylation of the monomers, decreases in thermal stability and streng th were found. For difunctional polymeric acrylates and epoxides, the glass transition temperature was measured. The average degree of curin g of UV-cured epoxy films can be determined from the temperature of th e maximum in the loss modulus (E-max'').