Non-Stoichiometric Curing Effect on Fracture Toughness of Nanosilica Particulate-Reinforced Epoxy Composites
Non-Stoichiometric Curing Effect on Fracture Toughness of Nanosilica Particulate-Reinforced Epoxy Composites
复制标题
非化学计量固化对纳米二氧化硅颗粒增强环氧复合材料断裂韧性的影响
DOI：
10.1007/s10853-014-8450-6
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发表时间：
2014
影响因子：
4.5
通讯作者：
Zoltan MAJOR
中科院分区：
文献类型：
--
作者：
Markus Karamoy UMBOH;Tadaharu ADACHI;Tadamasa NEMOTO;Masahiro HIGUCHI;Zoltan MAJOR
通过对比纳米SiO2颗粒增强环氧树脂复合材料的弯曲强度，研究了非化学计量固化对纳米SiO2颗粒增强环氧树脂复合材料断裂韧性的影响，以考虑纳米颗粒与基体树脂网络结构之间的相互作用。通过用双酚A型环氧树脂的二缩水甘油醚的过量混合物作为化学计量条件的固化剂固化它们来制备基质。对于所有复合材料，中值直径为240 nm的二氧化硅颗粒的体积分数恒定为0.2。纯环氧树脂和复合材料进行非化学计量固化，以改变纯环氧树脂和复合材料的基体树脂的交联密度在2740-490 mol/m3之间。复合材料和纯环氧树脂的断裂韧性和弯曲强度强烈依赖于树脂中的交联密度。虽然随着交联密度的降低，断裂韧性从化学计量固化树脂的断裂韧性单调下降，但复合材料的断裂韧性在从化学计量条件2740 mol/m3略低的交联密度（约2490 mol/m3）处最大。当交联密度大于2000 mol/m3时，粒子的加入提高了材料的断裂韧性和弯曲强度。在低于2000 mol/m3的交联密度下，颗粒作为基体树脂中的缺陷对机械性能起作用。
Non-stoichiometric curing effects on the fracture toughness behaviors of nanosilica particulate-reinforced epoxy composites were experimentally investigated in this study by comparing them with bending strengths to take into consideration the effect of interaction between nanoparticles and network structures in matrix resins. The matrixes were prepared by curing them with an excess mixture of diglycidyl ether of bisphenol A-type epoxy resin as the curing agent for the stoichiometric condition. The volume fractions of the silica particles with a median diameter of 240 nm were constantly 0.2 for all composites. The neat epoxy resins and the composites were cured non-stoichiometrically to change the crosslinking densities of the neat epoxy resins and the matrix resins of the composites within 2740–490 mol/m3. The fracture toughnesses and bending strengths of the composites and the neat epoxy resins strongly depended on the crosslinking densities in the resins. Although the fracture toughness decreased monotonously from that of the stoichiometrically cured resins as the crosslinking density decreased, the fracture toughnesses of composites were largest at a slightly lower crosslinking density of approximately 2490 mol/m3from the stoichiometric condition of 2740 mol/m3. The fracture toughness and the bending strength were improved for crosslinking densities higher than 2000 mol/m3by adding particles. At crosslinking density lower than 2000 mol/m3, the particles worked against the mechanical properties as defects in matrix resins.