Effect of filler porosity on the abrasion resistance of nanoporous silica gel/polymer composites.
Effect of filler porosity on the abrasion resistance of nanoporous silica gel/polymer composites.
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DOI：
10.1016/s0109-5641(98)00006-2
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
J. Luo;J. Lannutti;R. Seghi
中科院分区：
文献类型：
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作者：
J. Luo;J. Lannutti;R. Seghi
本实验旨在研究纳米控制孔径对硅胶增强聚合物基复合材料耐磨性的影响，并探讨其磨粒磨损性能的控制机制。方法采用四种不同的催化剂对正硅酸乙酯(TEOS)进行水解和缩合反应制备硅凝胶，并在凝胶粉末中引入一种含有不同引发剂的有机单体(TEGDMA)形成凝胶。然后将各种浆料在玻璃模具中聚合。然后用销盘装置记录样品的长度和旋转次数。磨粒磨损率通过回归分析确定，统计学差异通过方差分析和多重比较来确定。用BET表征了填料的孔结构，用扫描电子显微镜对磨损表面进行了观察。结果发现，实验复合材料的磨损率有显著差异(p<；0.05)。在所考察的填料孔隙率范围内，耐磨性与填料孔体积呈线性关系(R2=0.983)。磨损率随填料孔隙率的增加而降低。具有低孔隙率的氯化氢催化凝胶产生的复合材料具有相对有限的耐磨性。相反，高孔隙率的氢氟化氢催化凝胶可以产生更多的耐磨复合材料。这些纳米复合材料的耐磨性不受实验中使用的硅烷偶联程度的显著影响。扫描电子显微镜分析表明，较好的耐磨性与磨损面的细小塑性变形和填料颗粒的无拔出有关。显著的是，溶胶-凝胶法制备的多孔颗粒有望作为填料来改善光聚合树脂的耐磨性。填料的耐磨性似乎与凝胶颗粒的纳米孔结构直接相关。与传统的牙科复合材料不同，这些材料主要依靠纳米机械耦合来提高耐磨性。这一新原则应该有利于随后的调查。
ObjectivesThis laboratory study was designed to investigate the effect of controlled nanoporosity on the wear resistance of polymeric composites reinforced with silica gel powders and to determine the mechanisms controlling the abrasive wear properties of these unique nanostructured materials.MethodsSilica gels were prepared by hydrolysis and condensation of tetraethylorthosilicate (TEOS) using four different catalysts to modify the porous structure of the resulting polysilicate silanation, an organic monomer (TEGDMA) containing various initiators was introduced into the gel powders to form a paste. The various pastes were then polymerized inside a glass mold. A pin-on-disk apparatus was then used to record the specimen length and number of revolutions. Abrasive wear rates were determined by regression analysis and statistical differences were determined by analysis of variance and multiple comparisons. BET was used to characterize the filler pore structure and scanning electron microscopy was used used to visually examine the abraded surfaces.ResultsSignificant differences (p<0.05) in the wear rates of the experimental composites were noted. Within the range of filler porosities examined, wear resistance was found to be linearly dependent (R2=0.983) on filler pore volume. The wear rates decreased with increasing filler porosity. HCl-catalyzed gels having low porosity produced composites having relatively limited abrasion resistance. In contrast, high porosity HF-catalyzed gels produced more wear-resistant composites. The abrasive wear resistance of these nanocomposites was not significantly affected by the level of silane coupling used in these experiments. SEM evaluation suggested that better wear resistance was associated with fine-scale plastic deformation of the wear surface and the absence of filler particle pullout.SignificancePorous particles prepared via sol–gel show some promise as fillers that improve the wear resistance of photopolymerized resins. The wear resistance of the fillers appears to be directly related to nanoporous structure of the gel particles. Unlike conventional dental composites, these materials rely primarily on nanomechanical coupling for improved wear resistance. This new principle should benefit subsequent investigations.