A study of photo- and thermo-initiated polymerised dimethacrylates by three thermal analysis techniques

Photo-initiated polymerisation of dimethacrylate oligomers provide an easy method for producing highly crosslinked polymer networks. The physical prop erties of the material are dependent on the polymerisation conversion value . The determination of this conversion value is quite difficult on the fina l product. The first step is to measure a characteristic temperature of the glass transition. The weakness of the DSC glass transition signal makes th is measure unrealisable while the DMA tan peak is broad and weak. At the di fference of these two thermal analysis techniques, TSDC gives an observable signal and a T-alpha temperature close to the glass transition temperature region. The bad sample preparation reproducibility observed was attributed to the high conversion rate.