| A Phenolic Resin/Epoxy Resin Composite based on abandoned nutshell is studied in this paper, which can be used as low density proppant material in hydraulic fracturing. The composite is prepared by first impregnating crushed nutshell in Resol, and then enwrapped by Epoxy resin. Non-isothermal analysis kinetics method with several scan speed rate is applied to this paper, and linear heating-up data of DSC is used to study the mechanism model of PF/EF, PF/EF/TA by thermal curing. By in-situ FTIR, the changes of epoxy group, phenol hydroxyl and mono-substituted benzene are studied. The curing mechanism of triethanolamine used by accelerant is also discussed.1. The experimental results show that: when Resol's concentration is 70 percent, the ant-deformation ability of the composite is biggest. More Epoxy resin used, the ant-deformation ability of the composite is bigger and when EF resin's content is more than 25 percent, its ant-deformation ability do not change any more. TGA shows that its remaining mass fraction in 500 ℃is 45 percent, bigger than its before only 25 percent in the same condition. SEM shows that after enwrapped, its surface is more lubricity, less apertures. Absorbability in distilled water is dropped from 30.45 percent to 6.58 percent. Its conductivity ability is far bigger than made by only first procession of impregnating in resol, also exceeds quartz.2. From the results of thermal analysis kinetics, two exothermic peaks exhibit in PF/EF curing curve, only one peak in PF/EF/TA. The possible reason is that without accelerant, the activity of reaction is not enough, sc, its reaction results in low molecular weight with many hydroxyl groups. In the higher temperature, the reaction between the hydroxyl groups and remaining epoxy group, and the condensation reaction of hydroxyl groups will react again. The mechanism of PF/EF and PF/EF/TA can be both well fitted for by three steps function. From the curve of activity energy and conversion, in the first step, both of their activity energy ascends. In the second step, the autocatalytic reaction take place in them both, but the speed of PF/EF/TA is faster than PF/EF. At last step, their reaction speed is controlled by diffusion. In second step, the reactivity energy of PF/EF/TA is 58.3005KJ/mol, and it is lower than PF/EF (61.4838KJ/mol). Because TA accelerant, epoxy group and hydroxyl group form an intermediary agent, which reduce the reactivity energy, so its reaction speed is faster than PF/EF. At last step, their reaction speed is controlled by diffusion, the reactivity energy of PF/EF is128.603 KJ/mol, however, PF/EF/TA have reached 147.7355 KJ/mol. That's reason is that the reaction degree of PE/EF in second step carry out not completely, results in some low molecular weight and low degree cross-linking, so in the third step, the reaction by diffusion controlling can easily carry out with low energy reactivity than PF/EF/TA.3. Through analysis of in-situ FTIR, we find that epoxy group (912cm-1) index of PF/EF don't changes at all in the first ten minutes, while its of PF/EF/TA has dropped remarkably in the five minutes. Also the next reaction speed of PF/EF is much slower than PF/EF/TA. The decrease speed of mono-substituted benzene (γ(CH)690cm-1) index in PF is faster than in PF/EF and PF/EF/TA. The mono-substituted benzene (γ(CH)690cm-1) index in PF finally reach zero, however, its value of PF/EF and PF/EF/TA is not zero, and the value in PF/EF/TA is bigger than in PF/EF. During thermal curing, the evolution of hydroxyl phenol (vas (C-O) 1370cm-1) index of PF/EF/TA dropped faster than PF/EF, and its finally value is lower than PF/EF.All of this difference owe to the TA accelerant, because its use in PF/EF can substantially drop the activity energy. In this paper, the thermal curing mechanism of PF/EF/TA is also discussed. We think that because of the formation of "three-bulk complex", the activity energy can reduce substantially.
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