【作者】 唐富兰；

【导师】 莫健华；

【作者基本信息】 华中科技大学 ， 材料加工工程， 2006， 硕士

【摘要】 光固化快速成形是光照射到光敏树脂表面使之固化并层层叠加的一种成形技术。本文主要对光固化成形材料的改性进行了研究。光固化快速成形技术中,光敏树脂材料直接影响光固化制件的尺寸精度、力学性能和热性能,而目前开发出的光敏树脂制备的成形件存在着透明性差、表面质量不好、硬度低、韧性差、耐热性不好等缺点,这些不足阻碍了光固化技术的进一步发展,所以研究出一种高性能的成形材料具有非常重要的现实意义和使用价值。本文采用了纳米SiO₂改性光敏树脂的方法来提高成形材料的力学性能和热性能。首先论述了纳米SiO₂的表面改性,选用偶联剂作为纳米SiO₂的改性剂,研究了不同改性剂和反应条件对SiO₂亲油性的影响,确定了最佳改性剂和改性条件。通过红外光谱分析了改性SiO₂的表面基团,并测试了改性纳米SiO₂的亲油化度。结果表明纳米SiO₂经表面改性后亲油性明显提高,而且与偶联剂有效地发生了反应。将纳米SiO₂分散到光敏树脂中,制备了纳米SiO₂/紫外光固化树脂复合材料,用扫描电镜观察了复合材料固化后截面中粒径分布的形貌,发现改性SiO₂纳米粒子在树脂基体中分散均匀。对复合材料的固化件进行机械性能和耐热性测试,结果表明,改性后的固化件线收缩、体收缩有所降低,硬度、抗弯强度、韧性都有明显提高,耐热性也有一定提高,确定纳米SiO₂最佳填充量为1%-2%,对复合树脂进行了固化参数的测试,结果表明SiO₂的加入增大了光敏树脂的临界曝光量,降低了透射深度,但对树脂的固化成形没有影响。更多还原

【Abstract】 Stereolithography（SL） is the forming progress of the superposition when the photosensitive resins curing if exposured to the light . The modification of UV-curing resin was the main subject inveatigated in this paper.In SL, the photosensitive resins have direct effect on the dimensional accuracy, mechanical properties and thermal properties of the fabricated parts.At present there are some shortcomings in the fabricated parts such as bad transparency,bad surface quality,low hardness, bad toughness,low thermal stability. These insufficiencies have hindered further development of the photo-curing technology.Therefore, the developing of the superior materials for SL is meaningful and valuable.In the article nanometer SiO₂ was filled in the photosensitive resin to enhance the mechanical property and thermal stability of fabricated parts .At first the modification of nanometer SiO₂ was studied.Nanosilica was modified by different coupling agents.The effect of different modifiers and methods on hydrophobic stability of silica were studied.New groups on the surface of Nanosilica were characterized by FTIR,and the lipophilicity of the modified Nanosilica was tested.The results indicated that silicon responsed effectively with KH-560,and the hydrophobic stability of silica was greatly improved .The modified nanosilica was dispersed in the photosensitive resin,and nanosilica/UV curing resin composition was prepared.SEM experiment showed that silica nanoparticles were well dispersed in the resin. Property tests showed that modified parts had lower volume contraction and line contraction, hardness ,flexural strength,and toughness increased obviously,and thermal stability was also improved. The optimal proportion of nanosilica was 1%-2%.The parameter of photosensitive resin was tested.The result indicated the critical exposure increased , and the penetration depth becomed smaller after filled nanosilica,but there was little influence on cure of the photosensitive resin.更多还原