Wettability of silicone and polyether impression materials: Characterization by surface tension and contact angle measurements
Wettability of silicone and polyether impression materials: Characterization by surface tension and contact angle measurements
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DOI：
10.1016/j.colsurfa.2007.11.046
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发表时间：
2008-03-20
影响因子：
5.2
通讯作者：
Grundler, A.
中科院分区：
文献类型：
--
作者：
Grundke, K.;Michel, S.;Grundler, A.
通过测量表面张力和接触角，我们报告了未固化和固化聚合物压印材料的表面特性。研究了聚醚、加成固化和缩合固化有机硅三种压印材料。在聚醚体系中，碱的高表面张力约为50 mJ/m(2)，促进剂的高表面张力约为38 mJ/m(2)，分别是由极性羰基和醚基引起的。对于碱和促进剂，无论是否加入了固化硅酮的内部表面活性剂，硅酮的表面张力都在20到23 mj/m(2)之间。这些不同的表面张力值在液气界面导致未凝固和凝固的聚醚表面的亲水性和与水介质接触的有机硅的疏水性。然而，亲水性加成固化硅树脂的润湿性不能通过这些表面张力测量来预测。量化表面活性剂的影响以及固化过程中压印材料本体聚合的附加效应的一个好策略是测量与水的接触角。结果表明，在固化过程中，当材料中加入一种内部表面活性剂并迁移到最外层固液界面时，添加固化有机硅的润湿性会发生强烈的变化。未凝固材料和完全凝固材料上的水接触角大大降低到小于60度。水接触角的减小与水滴在扩散过程中液体表面张力的减小直接相关，这一点可以通过ADSA接触角测量得到证明。在部分凝固的体系中，随着聚合和交联的进行，表面活性剂向最外表面的迁移受到越来越大的阻碍，导致水接触角大于110。(c) 2007 Elsevier B.V.版权所有
We report the surface properties of unset and set polymer impression materials by performing surface tension and contact angle measurements. Three types of impression materials were investigated: polyether, addition cure and condensation cure silicones. The high surface tension of about 50 mJ/m(2) for the base and of 38 mj/m(2) for the accelerator of a polyether system is caused by polar carbonyl and ether groups, respectively. The surface tension of the silicones is in the range of 20 up to 23 mj/m(2) for both the base and the accelerator regardless of internal surfactants that were incorporated to the addition cure silicone. These different surface tension values at the liquid-air interface result in hydrophilic properties of the unset and set polyether surfaces and in hydrophobic surface properties for the silicones in contact with aqueous media. However, the wettability of an hydrophilized addition cure silicone could not be predicted by these surface tension measurements. A good strategy to quantify the influence of surfactants as well as the additional effect of the bulk polymerization of the impression material during setting are contact angle measurements with water. In this way, it was shown that the wettability of the addition cure silicones could be strongly changed during setting when an internal surfactant was added to the material that migrates to the outermost solid-liquid interface. The water contact angles on the unset material and on the completely set material were lowered considerably to less than 60 degrees. The decrease of the water contact angle was directly related to the decrease in the liquid surface tension of the water droplet during spreading as could be proved by ADSA contact angle measurements for the set silicone system. In the partly set system, the migration of the surfactant to the outermost surface was increasingly hindered with the progression of the polymerization and cross linking resulting in high water contact angles of more than 110. (c) 2007 Elsevier B.V. All rights reserved.