Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO...Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol^(-1)·1·s^(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.展开更多
In order to reduce shrinkage and improve the mechanical properties of dental composite resins, we designed a hybrid resin formulation containing a novel matrix resin, Bis S-GMA [bisphenol-Sbis（3-methacrylato-2-hydrox...In order to reduce shrinkage and improve the mechanical properties of dental composite resins, we designed a hybrid resin formulation containing a novel matrix resin, Bis S-GMA [bisphenol-Sbis（3-methacrylato-2-hydroxypropyl）ether], and epoxy modifi ed by a spiro-orthocarbonate（SOC） expanding monomer. Then, we tested the effects of an iodonium salt, diphenyliodonium hexafl uorphosphate（DPIHFP）, on the properties of the hybrid resin with seven different concentrations. The hybrid resin was polymerized by a ternary photo-initiator system. The volumetric shrinkage（VS）, degree of conversion（DC） and compressive strength（CS） were assessed using Acu Vol^TM, FTIR and a universal testing machine, respectively. The VS, DC and CS were improved with increasing DPIHFP concentration, but a high concentration of DPIHFP had a negative infl uence on the mechanical properties of the hybrid resin and offered no added improvement in the VS and DC. The best performance of a composite resin containing Bis S-GMA and SOC-modifi ed epoxy was achieved with 2wt% DPIHFP. The results also indicated that the resin containing Bis S-GMA was superior to that containing Bis-GMA in terms of VS, DC and CS.展开更多
文摘Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol^(-1)·1·s^(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.
基金Funded by the National Natural Science Foundation of China(No.50673065)
文摘In order to reduce shrinkage and improve the mechanical properties of dental composite resins, we designed a hybrid resin formulation containing a novel matrix resin, Bis S-GMA [bisphenol-Sbis（3-methacrylato-2-hydroxypropyl）ether], and epoxy modifi ed by a spiro-orthocarbonate（SOC） expanding monomer. Then, we tested the effects of an iodonium salt, diphenyliodonium hexafl uorphosphate（DPIHFP）, on the properties of the hybrid resin with seven different concentrations. The hybrid resin was polymerized by a ternary photo-initiator system. The volumetric shrinkage（VS）, degree of conversion（DC） and compressive strength（CS） were assessed using Acu Vol^TM, FTIR and a universal testing machine, respectively. The VS, DC and CS were improved with increasing DPIHFP concentration, but a high concentration of DPIHFP had a negative infl uence on the mechanical properties of the hybrid resin and offered no added improvement in the VS and DC. The best performance of a composite resin containing Bis S-GMA and SOC-modifi ed epoxy was achieved with 2wt% DPIHFP. The results also indicated that the resin containing Bis S-GMA was superior to that containing Bis-GMA in terms of VS, DC and CS.
