Curing And Properties Of Epoxy Resin Casting System

Epoxy resin exhibites excellent strength and resistance to acid,alkali,corrosion,and so on,which is widely used in road repair,bridge reinforcement,cementing and plugging field.With the development of oil and gas wells in China,improving cementing quality and ensuring oil and gas mined,epoxy resin casting materials have become the preferred material in cementing engineering.However,after the added of the curing agents,the curing rates of the epoxy resin was increased due to the high viscosity and poor fluidity,which is likely to cause blockage of the pipe.On the other hand,the density of the material was different in different pressure layers,and the casting material needs to be modified to reduce the viscosity,control the curing reaction rate,and regulate the density of the materials by adding inorganic fillers.By non-isothermal DSC method,the properties of curing agents were studied in this study.The casting material's controllability from the gel time,thickening time,modification of the filler to the material's density,mechanical properties and thermal performance were analyzed.The main research contents wree as follows:(1)Through the non-isothermal DSC of the curing agents D39 and 651,it exhibied that the characteristic temperature of the E51/651 curing system was higher than E51/D39system,and the curing agent 651 was more active than D39.At the same temperature and the same curing degree,the curing rate of E51/651 curing system was greater than E51/D39curing system.(2)For epoxy casting system,the effects of diluent,curing agent,accelerator and temperature on gel time,thickening time and compressiv property were investigated,the results showed that benzyl glycidyl ether has better effect on reduce the viscosity of E51,and the appropriate content of diluent was 30%.The gel time and thickening time of the epoxy casting system were shortened with the increase of temperature,curing agent dosage and accelerator dosage,and the mechanical properties were gradually increased.The gel time of the casting system was controllable within 120-240 min,and the compressive strength of the material was varied from 50MPa to 80 MPa.(3)With quartz sand surface modified with KH-560,the epoxy resin composite casting system was prepared.The results of infrared spectrum and particle size distribution proved that the coupling agent reacted with quartz sand,and the proper content of KH-560 was1.5%.With the content of quartz sand increased,the gel time and thickening time are prolonged,the distribution index of the particles was increased,and the density of the material was changed from 1.13 to 1.38 g/cm~3.Due to modified quartz sand,the compressive and thermal properties of the epoxy resin composite materials were improved,and at the content of 10%,the compressive strength was 81.8MPa,which is increased by47.6%than before adding quartz sand.(4)The surface modified of KH-560 improved the epoxy resin wettabilityon cenosphere,and the proper content of KH-560 was 1.2%.With the increase content of cenosphere,the gel time and dispersion index increase,and the garavity density varies from0.90 to 1.13 g/cm~3.The compressive strength was 62.8MPa,which is increased by 13.4%before adding cenosphere at the cenospheres content was 10%.Compared with the unmodified cenosphere,the glass transition temperature increased by 8?.