Study On Curing Behavior And Dynamic Mechanical Property Of Multi-Walled Carbon Nanotubes/Epoxy Nanocomposites

Multi-Walled Carbon Nanotubes (MWNTs) /epoxy nanocomposites were prepared by radiation curing and heat curing, it was first time to prepare MWNTs/epoxy nanocomposites byγ-ray radiation curing and electron beam (EB) curing. The gel contents, the conversion rates, heat flow curves and dynamic mechanical property were determined by the Soxhlet extraction method, Fourier transform infrared spectrum (FT- IR), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) technique respectively. Scanning electron microscope (SEM) was used to observe the microstructure of the composites. Multi-Walled Carbon Nanotubes /epoxy nanocomposites were prepared by three ways. It evaluate the different influence of different kinds of curing ways and the contents of MWNTs and a-MWNTs on the structure and properties of MWNTs/epoxy composite .Through SEM, we observed that there were a lot of defects around MWNTs in MWNTs/ epoxy nanocomposites, the raw MWNTs were long, trend to tangle.The main results indicated that:The gel content of the composites prepared by heat curing were higher than the gel content of the epoxy resin curing system prepared by heat curing; When the contents of MWNTs in the curing composites system is 1.5wt%, the gel content of the composites began to decrease.When the MWNTs incorporated into the epoxy resin curing system, the storage modulus of the composites firstly fell; however with increasing of the content of MWNTs, then the storage modulus heightened. MWNTs incorporated into the epoxy resin curing system is helpful to boost the glass transition temperature of the composites, also enhanced the internal friction of the composites; but when the contents of MWNTs in the composites system is excessive, MWNTs tend to congregate and have much more defects, the internal friction of the composites reduce.MWNTs/epoxy nanocomposites were prepared for the first time byγ-ray radiation curing, the gel content of the composites increased with the increasing of radiation dosages and photoinitiator's concentration.Because MWNTs may have some different influences on the active centers of reactions, at the beginning, when MWNTs incorporated into the epoxy resin curing system, the conversion rates firstly decreased, however with increasing of the content of MWNTs, then the conversion rates increased. Because of MWNTs incorporated into the epoxy resin curing system, the curve of DSC of the epoxy resin curing system had a endothermic peak around 105℃which disappeared in the curve of DSC of the composites; When the contents of MWNTs in the epoxy resin curing system achieved 0.5wt%, the curve of its DSC was very special:the two exothermic peak were coincided in Temperature Range 80℃to 150℃,and the heat curve shift to exotherm curve instant in 150℃.The raw MWNTs/epoxy nanocomposites and the acidizing MWNTs/epoxy nanocomposites were prepared by EB curing. The gel contents, the conversion rates of the composites were higher than the gel content, the conversion rates of the epoxy resin curing system. The gel contents, the conversion rates of the raw MWNTs/epoxy nanocomposites increased with the increasing of the contents of MWNTs in the raw MWNTs/epoxy nanocomposites; For the acidizing MWNTs/epoxy nanocomposites, when the MWNTs incorporated into the epoxy resin curing system, the gel contents, the conversion rates firstly increased, however with increasing of the content of MWNTs, then the conversion rates decreased. With adding MWNTs into the epoxy resin curing system, it had no obvious influence on the curve of DSC of the raw MWNTs/epoxy nanocomposites, but it found that the acidizing MWNTs/epoxy nanocomposites began to thermal decompose at 200℃.The storage modulus of the acidizing MWNTs/epoxy nanocomposites fell with increasing of the contents of MWNTs. Adding MWNTs into the epoxy resin curing system heightened the glass transition temperature of the composites, increased the enhanced the internal friction of the composites; but when the contents of MWNTs achieved 2wt%, MWNTs tend to congregate, decreased the internal friction of the composites.