Photoinitiated polymerization of a dimethacrylate oligomer part 3. Postpolymerization study

The effects of the presence of trapped radicals after UV irradiation were s tudied on a dimethacrylate oligomer. The postpolymerization reaction was ch aracterized by differential scanning calorimetry and dynamic mechanical ana lysis. The photopolymerization was realized with 2,2-dimethyl-2-hydroxyacet ophenone (Darocur 1173) as radical photoinitiator by using isothermal photo calorimetry. The postpolymerization was clearly shown in the isothermal mod e and under N-2 atmosphere by following the variation of the glass transiti on temperature of the samples. The influence of crosslinking density, O-2 a nd thermal postcure were investigated. (C) 1999 Elsevier Science Ltd. All r ights reserved.