Synthesis and evaluation of N,N-dimethyl-N′,N′-di[2-(methylacryloyl)-ethoxycarbnylethyl] propyldiamine as a coinitiator

The common diluent and coinitiator for current dental resin composite were triethylene glycol dimethylacrylate (TEGDMA) and ethyl-4-dimethylaminobenzoate (EDMAB), respectively. In this study, a polymerisable coinitiator N,N-dimethyl-N′,N′-di[2-(methylacryloyl)-ethoxycarbnylethyl] propyldiamine (DMPDA) was synthesized via Michael-Addition reaction. A mixture of 2,2-bis[4-(2-hydroxy-3-methacryloxy propoxy)phenyl]-propane (Bis-GMA)/TEGDMA/camphorquinone (CQ) (75%:25%:0.5% w/w/w) with different coinitiators (i.e. DMPDA, EDMAB or 2-(dimethylamine)ethyl methacrylate (DMEM)) and concentrations were photopolymerized. The kinetics was monitored by real time infrared spectroscopy (RT-IR) and the mechanical properties were measured by dynamic mechanical analyzer (DMA). The results indicated that both the double bond conversion and the rate of polymerization of the resin mixtures increased as increasing the concentration of the DMPDA but were lower than that of EDMAB and DMEM at the same concentration. The modulus and Tg of the cured samples were very close. Water sorption and solubility of the samples were almost the same. It was potential to be used as a coinitiator for dental composite.