Effects of residual ethanol on the rate and degree of conversion of five experimental resins.
Effects of residual ethanol on the rate and degree of conversion of five experimental resins.
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DOI：
10.1016/j.dental.2008.11.005
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发表时间：
2009-05
期刊：
影响因子：
5
通讯作者：
Pashley, David H.
中科院分区：
文献类型：
--
作者：
Cadenaro, Milena;Breschi, Lorenzo;Rueggeberg, Frederick A.;Suchko, Michael;Grodin, Evan;Agee, Kelli;Di Lenarda, Roberto;Tay, Franklin R.;Pashley, David H.
本研究检查了乙醇保留在实验甲基丙烯酸酯基牙科粘合剂，含有（10，20，或30重量%）乙醇，溶剂蒸发后的五个共聚单体共混物的程度，以及观察残留的乙醇和曝光时间的转化度（DC）的影响。检验的零假设是残留的未蒸发乙醇对聚合粘合剂树脂的DC速率或程度没有影响。将已知质量的每种混合物置于玻璃威尔斯孔中并蒸发60秒。测量蒸发之前和之后的混合物的质量，允许计算重量乙醇损失/保留。保留的乙醇浓度随乙醇浓度显著增加（p<0.01）：10%乙醇/90%共聚单体为1.1-1.9摩尔/L，20%乙醇为2.2-3.5摩尔/L，30%乙醇/70%共聚单体为2.6-3.7摩尔/L。随着乙醇从溶剂化的共聚单体混合物中蒸发，共聚单体的摩尔浓度增加，从而降低剩余乙醇的蒸气压。因此，乙醇溶剂的分数损失随着共聚单体浓度的增加而降低。在5种实验树脂中的4种中，10、20和30重量%乙醇共混物的DC随乙醇浓度增加（p<0.05），当将10或20重量%乙醇添加到纯树脂中时，DC增加30至45%，而与暴露持续时间无关。取决于树脂系统，包含30%乙醇在20秒时降低DC，但在40-60秒的光暴露后增加DC。由于10和20重量%乙醇-树脂共混物使溶剂化树脂的DC比纯树脂增加30-45%，因此拒绝检验零假设。即使延长蒸发时间，在90/10（wt/wt）共聚单体/乙醇混合物中也可保留4-9%的残留乙醇浓度。这被认为是因为共聚单体降低了乙醇的蒸气压。该量的残留乙醇促进了DC，但降低了聚合速率。
This study examined the extent of ethanol retention in five comonomer blends of experimental methacrylate-based dental adhesives, containing (10, 20, or 30 wt%) ethanol, after solvent evaporation, as well as observing the effect of residual ethanol and exposure duration on degree of conversion (DC). The null hypothesis that was tested was that residual, unevaporated ethanol has no effect on the rate or extent of DC of polymerized adhesive resins. A known mass of each mixture was placed in glass wells and evaporated for 60 sec. The mass of the mixtures before and after evaporation was measured, allowing calculation of the gravimetric ethanol loss/retention. The concentration of retained ethanol increased significantly with ethanol concentration (p<0.01): 1.1–1.9 moles/L for 10% ethanol/90% comonomers, 2.2–3.5 moles/L for 20% ethanol, and 2.6–3.7 moles/L for 30% ethanol/70% comonomers. As ethanol is evaporated from solvated comonomer mixtures, the molar concentration of comonomers increases, reducing the vapor pressure of the remaining ethanol. Thus, the fractional loss of ethanol solvent decreases as the comonomer concentration increases. The DC of 10, 20, and 30 wt% ethanol blends increased with ethanol concentration in 4 of the 5 experimental resins (p<0.05), increasing by 30 to 45% when 10 or 20 wt% ethanol was added to neat resins, regardless of exposure duration. Depending on the resin system, inclusion of 30% ethanol lowered DC at 20 s but increased DC after 40–60 sec of light exposure. Since 10 and 20 wt% ethanol-resin blends increased the DC of solvated resins by 30–45% over neat resins, the test null hypothesis is rejected. Even with prolonged evaporation, 4–9% residual ethanol concentration can remain in 90/10 (wt/wt) comonomer/ethanol mixtures. This is thought to be because comonomers lower the vapor pressure of ethanol. This amount of residual ethanol facilitates DC but lowers the rate of polymerization.
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影响因子：
14
作者：
Ito, S;Hashimoto, M;Pashley, DH
通讯作者：
Pashley, DH
影响因子：
2.9
作者：
Bala, O;Ölmez, A;Kalayci, S
通讯作者：
Kalayci, S
影响因子：
5
作者：
ELIADES, GC;VOUGIOUKLAKIS, GJ;CAPUTO, AA
通讯作者：
CAPUTO, AA
影响因子：
5
作者：
Cadenaro, Milena;Breschi, Lorenzo;Pashley, David H.
通讯作者：
Pashley, David H.
影响因子：
2.6
作者：
Mills, RW;Jandt, KD;Ashworth, SH
通讯作者：
Ashworth, SH