摘要
通过把有机蒙脱土(oMMT)分散到环氧树脂(EP)中制备出环氧树脂/有机蒙脱土(EP/oMMT)纳米复合材料。利用原子力显微镜(AFM)和扫描电子显微镜(SEM)对EP/oMMT纳米复合材料的微观结构进行了分析表征,利用热重分析仪、马丁耐热试验仪、冲击试验仪和介损分析仪测试了该复合材料的耐热性能、机械性能和介电性能。结果表明:有机蒙脱土以球形和蜷曲带形两种形态存在于树脂基体中,平均尺寸为20nm;混合温度为90℃时所得复合材料中oMMT的分散性较好,EP和oMMT的两相界面粘接也较好,复合材料的马丁耐热温度和冲击强度比未改性树脂分别提高了10℃和31.6%。复合材料的冲击强度随蒙脱土含量的增加而提高,并在蒙脱土含量为2phr时达到最大值23.6kJ/m2;通过研究复合材料的两相结构与冲击韧性的关系,推断出蒙脱土增韧环氧树脂的增韧机理为基体的剪切屈服机理;复合材料的介电常数(εr)和介电损耗角正切(tanδ)均有所降低,εr随温度的变化趋势与未改性环氧树脂相似,而蒙脱土的加入延缓了tanδ随温度增加而增大的速率。
In this paper montmorillonite modified with alkyl ammonium ions is dispersed in an epoxy/methyl nadic anhydride systems to form epoxy/organo-Montmorillonite（oMMT） nanocomposite. Scanning electric microscopy （SEM） and atomic force microscopy （AFM） are used to characterized the microstructure of nanocomposite obtained. Mechanical properties, thermal properties and dielectric properties of the nanocomposite are studied using impact tester, Martin heat resistance tester, dielectric loss analyzer. The results proved that, there are two kinds of shapes of oMMT dispersed in epoxy, either sphericity or cingulum, the average dimension is 20nm. The oMMT dispersed uniformly in nanocomposite with mixing temperature is 90℃, compared to the unmodified epoxy, the martin heat resistance temperature and impact strength of the composite improved 10℃ and 31.6%, respectively. The maximum of impact strength of nanocomposite is obtained when the oMMT loading is 2phr （per hundred resin） . SEM and AFM photograph are showed that the thermal stability and toughness of the composite are all related to the dispersion of montmorillonite, and the impact strength of composite is related to the adhesive joining of the interface between epoxy and montmorillonite. The relationship between microstructure and properties of the composite is studied, then toughen mechanism of montmorillonite toughen epoxy is speculated as massive shear yielding. The value of the er is lower than that of pristine epoxy materials, the increase of the tan8 with the temperature is delayed. The possible reason is that the mobility of polymer chains is restricted between the layers of MMT.
出处
《电工技术学报》
EI
CSCD
北大核心
2006年第4期29-34,共6页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(50377009)
关键词
环氧树脂
有机蒙脱土
纳米复合材料增韧
介电性能
Epoxy, organo-montmorillonite, nanocomposites toughness, dielectric properties
