Thioxanthone-carbazole as a visible light photoinitiator for free radical polymerization

A thioxanthone (TX) derivative with the additional carbazole chromophore, namely thioxanthone-carbazole (TX-C) was synthesized and characterized. The photophysical properties and its efficiency to polymerize methyl methacrylate both in the presence and absence of N,N-dimethylaniline (DMA) as coinitiator was investigated and compared with that of the commercially available TX. TX-C was found to display better photophysical properties and in both cases initiate polymerization more efficiently. Detailed real-time Fourier transform infrared studies revealed that high polymerization rates can be obtained when TX-C in conjunction with DMA was used.