| Encapsulating materials of epoxy resin are modified with HGH, nano-SiO2 and organophilic montmorillonite, in the present investigation, the microstructue, some properties and influence factors about nano-SiO2 and organophilic montmorillonite modified Encapsulatig materials have been systematically studied using X-ray diffraction, electron microscopy and differential thermal analysis measurement techniques.The modified epoxy resin materials with HG and HGH have first been preformed. Properties test results show that the electricity properties and heat distortion temperature are improved by addition of HG or HGH in the epoxy resin materials, and the materials containing HG or HGH have lower linear thermal expansion coefficiency compared with neat epoxy resin. When the modified materials were in water for 24 hours, the mechanical properties and electricity properties of the materials with HGH are better than that of the materials with HG.Epoxy resin/nano- SiO2 composite materials were obtained from in situ polymerization, and then the microstructure and properties of the materials are investigated by transmission electron microscopy, scanning electron microscopy and differential scanning calorimetry,etc.Results indicated that the microstructure of the modified materials shew the structure of nanometer materials, and the mechanical properties, heat distortion temperature and electricity properties and of the materials were all improved by addition of nano- SiO2 .After the nano-SiO2 was pretreated with organic silicon coupling agent (H2N-CH2CH2CH2-Si(OC2H5)n), the nano-SiO2 particles were dispersed in epoxy resin matrix homogeneously. When the content of nano-SiO2 is3wt%, the mechanical properties of the nanocomposites were the best, impact strength is 98% higher than that of epoxy resin, flexural strength is 112% higher than when nano-SiO2 is Owt%. The differential scanning calorimetry analyses show that the addition of nano-SiO2 increases the glass transition temperature.Organophilic montmorillonite was obtained by cation exchange on montmorillonite surface, which was modified from hydrophilic to hydrophobic and led to the increase in the basal distance between silicate layers of about 1nm. The intercalation and exfoliation behavior of organophilic montmorillonite in DGEBA-montmorillonite system have been investigated by X-ray diffraction and transmission electron microscopy and the properties of nanocomposites were tested. The results show that the affinity between the organophilic montmorillonite and diglycidylether of bisphenol A was very well. Curing agents and mixing conditions were two important factors that effected on exfoliation behavior of organophilicmontmorillonite in diglycidylether of bisphenol A matrix. The organophilic montmorillonite was exfoliated completely and there were no d001 diffraction peaks with methyltetrahydrophthalic anhydride as curing agent and benzyldimethylanine as catalyst. Properties test results show that mechmical properties, electricity properties ,heat distortion temperature of the exfoliated nanocomposites were all improved by addition of the montmorillonite, and the nanocomposites had lower linear thermal expansion coefficiency and water absorption compared with neat epoxy resin.Based on the over research ,three different kinds of encapsulating materials of epoxy resin are performed. Test results show that that the breakcown voltage and heat distortion temperature the encapsulating materials of epoxy resin with HGH are famously improved, but the the addition of HGH, the viscosities of the epoxy resin-HGH system is higher compared with that of the others and the encapsulating process is effected. Nano- SiO2 improves the mechanical properties of encapsulating materials of epoxy resin,impact strength reaches 27.64kJ/m2 from 13.95 kJ/m2 ,flexural strength reaches 136.68MPa from64.95 MPa. by addition of the montmorillonite, glass transition temperature and heat distortion temperature of the encapsulating materials are 13.2℃ and 16℃ higher than that of epoxy re... |
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