Preparation And Study On Property Of Epoxy Resin/Na~+-Bentonite Composite

Epoxy resin is widely used in the military affairs,aviation aerospace,structure,electrics and electric equipment and so on because of it's excellent properties such as splice, insulation, low contraction and low price. But because of it's fragility and the relatively low temperature of thermal stability, its use is limited in some fields. So how to enhance it's toughness and intensity has become the hot issues internationally and domestically . The recent modifying methods enhanced the materials'toughness meanwhile lowed the materials'thermal stability. In recent years,because of the fast development of science of silicate, to composite the polymer and silicate with the organic Modification to prepare the organic-inorganic materials, which can give play to the organic-inorganic object's excellent property, has provided a new way to the modification of epoxy resin.Firstly, this paper has sodium modified the Ca-bentonite to prepared the Na-bentonite, The result indicates: the property of Na-bentonite which is prepared by the optimal process:NaCO3 wt3%,sodium temperature 70℃,sodium time2.0h is better than Ca-bentonite.This paper used alkylamine'molecule to prepare the organicbentonite, XRD testing indicated that the lamellar distance of Na-bentonite can be obviously extended by the octadecylamine, the lamellar distance modified by the optimal process is the best, improved 48% than before, FTIR and TGA testing indicated that the fundamental structure of the organobentonites didn't vary, meanwhile the octadecylamine has been inserted into the lamellar, which is better for them to mix and scatter with each other; This paper used the E51 epoxy resin/bentonite system to prepare the composites.The experiment claims that to chose the 90% content of the curing agent, and to mix the organicbentonite with the curing agent firstly is better for the organicbentonite to scatter in the composites and to improve the materials'synthetical property. The optimal process is curing time150min,the curing temperature 100℃,time of deaeration 15min; XRD testing indicates that the first diffraction peak of the composites has been disappeared, the modification of epoxy resin extends the lamellar distance, some of them has been stripped; on the 3%~4% content of bentonites, the composites'tensile strength and impact strength has been the best, and both of them are better than the pure epoxy resin;the SEM of materials'fracture surface indicates that the epoxy resin's fracture surface is smooth and plane, it's typical fragile fracture, the composites'fracture surface has initiated plenty of extremely tiny flaw, it's the tenacious characteristic;TGA experiment indicates that the composites'initial resolution temperature is 11.6℃higher than pure epoxy resin,it shows that the composites'thermal stability is improved than before; the composites'breakdown electrical field is best when the content of the bentonite is 3%~5%, and which is better than the pure epoxy resin and the dielectric properties is also improved.