Objective

To determine the effect of organosilane content on the physicochemical properties of model composites formulated with nano-sized fillers.

Methods

Model composites were formulated with dimethacrylate-based monomers, a photoinitiator/co-initiator system and silicon dioxide nano-sized fillers treated with different amounts of 3-methacryloxypropyltrimethoxysilane (MPTS): 1.0 (G_1%), 2.0 (G_2%), 5.0 (G_5%), 7.5 (G_7.5%) and 10 (G_10%) wt.% relative to SiO₂. Non-silanized fillers (G_0%) were used in the control group. Degree of conversion (DC) was assessed by Fourier-transformed infrared spectroscopy (ATR-FTIR). Knoop hardness (KHN) and elastic modulus were determined before and after water storage for 4 months. Water sorption (Wsp) and solubility (Wsl) were calculated by successive mass determinations in analytical balance. Surface gloss and roughness were characterized before and after toothbrushing simulation.

Results

With the exception of those fillers treated with 1% MPTS, DC was not dependent on the silane content. Within the silanized groups, G_1% showed the lowest initial and final KHN, without statistical difference from G_0%. The elastic modulus was not affected by the silane content, regardless of the storage condition, but those groups formulated with at least 5% silane presented improved values after storage. Silane content did not affect the WSl, but affected Wsp, in which those groups formulated with at least 2 wt.% of MPTS produced a more resistant material than G_0%. The use of treated particles with at least 2 wt.% of silane was able to produce materials that did not change their gloss after the brushing process. Additionally, these materials presented lower surface roughness than G_0% after the brushing process (p < 0.05).

Significance

The concentration of MPTS affected the physicochemical properties of nano-filled composites. Therefore, 2 wt.% of silane was the optimized quantity to produce materials resistant to degradation, both in bulk and surface properties.

中文翻译：

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硅烷含量影响纳米结构模型复合材料的理化性能

目的

要确定有机硅烷含量对用纳米级填料配制的模型复合材料的物理化学性质的影响。

方法

使用基于二甲基丙烯酸酯的单体，光引发剂/共引发剂体系和用不同量的3-甲基丙烯酰氧基丙基三甲氧基硅烷（MPTS）处理的二氧化硅纳米尺寸填料配制模型复合材料：1.0（G _1％），2.0（G _2％），相对于SiO ₂为5.0（G _5％），7.5（G _7.5％）和10（G _10％）wt。％。非硅烷化填料（G _0％）用于对照组。转化度（DC）通过傅里叶变换红外光谱（ATR-FTIR）进行评估。在储水4个月之前和之后测定努努普硬度（KHN）和弹性模量。通过分析天平中的连续质量测定来计算吸水率（Wsp）和溶解度（Wsl）。在牙刷模拟之前和之后表征表面光泽度和粗糙度。

结果

除了那些用1％MPTS处理过的填料外，DC并不取决于硅烷含量。在硅烷化组中，G _1％显示出最低的初始和最终KHN，与G _0％没有统计学差异。不管储存条件如何，弹性模量都不受硅烷含量的影响，但是由至少5％的硅烷配制的那些基团在储存后表现出改善的值。硅烷含量不影响WS1，但影响Wsp，其中用至少2 wt。％的MPTS配制的那些基团产生的抗性材料比G _0％。使用具有至少2重量％的硅烷的处理过的颗粒能够产生在刷涂过程后不会改变其光泽的材料。此外，这些材料在刷牙后的表面粗糙度低于G _0％（p <0.05）。

意义

MPTS的浓度影响了纳米填充复合材料的理化特性。因此，2wt。％的硅烷是用于生产在体积和表面性质上均抗降解的材料的最适量。