Effect of coinitiator and water on the photoreactivity and photopolymerization of HEMA/camphoquinone-based reactant mixtures
Effect of coinitiator and water on the photoreactivity and photopolymerization of HEMA/camphoquinone-based reactant mixtures
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DOI：
10.1002/jbm.a.30733
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发表时间：
2006-09-15
影响因子：
4.9
通讯作者：
Ye, Qiang
中科院分区：
文献类型：
--
作者：
Wang, Yong;Spencer, Paulette;Ye, Qiang
先前报道，在水的存在下，市售的光活化BisGMA/HEMA粘合剂经历物理分离成固体富含BisGMA的颗粒和流体状富含HEMA的相。富HEMA相表现出有限的单体转化率，表明光引发剂定位于疏水相或光引发剂与亲水性HEMA不相容。本研究的目的是确定与亲水性富HEMA相相容的光引发剂，当制备混合物时不添加水和添加水。光引发剂是邻甲苯胺酮（CQ，0.5摩尔%），共引发剂（0.5摩尔%）是2，2 ′-二羟乙基-对甲苯胺（DHEPT）、甲基丙烯酸二甲氨基乙酯（DMAEMA）和N-苯基甘氨酸（NPG），以及（1重量%）二苯基碘鎓氯化物（DPIC）。反应性使用光差示扫描量热法在37 ° C下使用可见光（> 418 nm）进行评价，所确定的参数为焓（Δ H）、诱导时间（本文定义为1%的光聚合完成的时间）和最大Δ H出现的时间。使用显微拉曼光谱测量单体转化的程度。结果表明，反应性排序（基于达到最大峰值的时间和总焓）为HEMA/CQ/DHEPT < HEMA/CQ/DMAEMA < HEMA/CQ/NPG。在DPIC存在下，CQ/DMAEMA和CQ/NPG的反应性显著增加，但CQ/DHEPT的反应性不增加。水对HEMA转化率有重要影响。在10%的水下，用CQ/DMEMA配制的HEMA的转化率水平从类似于100%下降到86%。相比之下，当使用DPIC时，在10%的水中的转化率增加到接近96%。结果表明，DHEPT，这是常用的商业粘合剂，是不兼容的HEMA。NPG和DMAEMA都与HEMA兼容。离子型亲水性碘鎓盐DPIC即使在水存在下也能增强HEMA的聚合。水相容性光引发剂的未来研究应进行，以解决水对牙本质粘合剂系统的不利影响。(c)2006 Wiley Periodicals，Inc.
It was reported previously that, in the presence of water, a commercially available light-activated BisGMA/HEMA adhesive underwent physical separation into solid BisGMA-rich particles and a fluid-like HEMA-rich phase. The HEMA-rich phase exhibited limited monomer conversion suggesting that the photoinitiator is localized to the hydrophobic phase or that the photoinitiator is not compatible with the hydrophilic HEMA. The objective of the present study was to identify photoinitiators that are compatible with the hydrophilic HEMA-rich phase, when the mixtures are prepared without and with water added. The photoinitiator was camphocluinone (CQ, 0.5 mol %), and the comitiators (0.5 mol %) were 2,2'-dihydroxyethyl-para-toluidine (DHEPT), dimethylaminoethyl methacrylate (DMAEMA), and N-phenylglycine (NPG), and (1 wt %) diphenyliodonium chloride (DPIC). Reactivities were evaluated using photodifferential scanning calorimetry, at 37 degrees C, using visible light (> 418 nm), with the parameters determined being enthalpy (Delta H), the induction time (herein defined as the time for 1% of the photopolymerization to be complete), and the time at which the maximum exotherm occurred. The degree of monomer conversion was measured using micro-Raman spectroscopy. It was shown that the reactivity ranking (based on time to exotherm peak maximum and total enthalpy) was HEMA/CQ/DHEPT < HEMA/CQ/DMAEMA < HEMA/CQ/NPG. Reactivity was dramatically increased for CQ/DMAEMA and CQ/NPG in the presence of DPIC, but not for CQ/DHEPT. Water has a major effect on HEMA conversion. At 10% of water, the conversion level of HEMA formulated with CQ/DMEMA dropped from similar to 100% to 86%. In comparison, the conversion in 10% of water increased to nearly 96% when DPIC was used. The results suggest that DHEPT, which is commonly used in commercial adhesives, is not compatible with HEMA. Both NPG and DMAEMA appear compatible with the HEMA. The ionic hydrophilic iodonium salt, DPIC, enhances the polymerization of HEMA, even in the presence of water. Future studies on water-compatible photoinitiators should be performed to address the detrimental effects of water on dentin adhesive systems. (c) 2006 Wiley Periodicals, Inc.