A Research On The Synthesis Technic Of A No-nitrogen Furan Resin With A High Strength And A Low Cost Used In Steel-Casting

As a binder of foundry, furan resin which has a high strength, a good dimensionalaccuracy, a high efficiency, a low intensity of labor, is used widely in actual production.However, some kinds of furan resin made domestically has a strong odor because of thehigh amount of free formaldehyde in it. The price of furfural alcohol has been very high forthese years，so the price of furan resin is also high to limit widely use of furan resin insome way．This paper is a research on the synthesis process of a no-nitrogen furan resin.With a high strength and a low odor and a low cost.First of all, the mechanism of no-nitrogen furan resin was analyzed for synthesis.Acetone and phenol, formaldehyde, furfural alcohol were chosen as main raw materials insynthesis, they were analyzed on the synthesis process for acetone phenolic modified furanresin and keto-aldehyde modified furan resin, acetone modified synthesis process waschosen by contrast in the end.Next by orthogonal test, the keto-aldehyde furan resins synthesis process wasoptimized. Through the analysis of experimental data, a optimized craft was obtained, thetemperature of alkaline reaction is80℃,the time of alkaline reaction is2h,the PH ofalkaline reaction is9.5,the temperature of acid reaction is85℃, the time of acid reaction is1.5h,the PH value of acid reaction is4.1,the quantity of dehydration is60%toformaldehyde. The strength of resin of24h was2.3MPa and the content of freeformaldehyde was0.27%, the viscosity was30mpa·s.To reduce the price of resin, ethanol、glycerol、a polyol A agent were added to replacefurfural alcohol partly. Finally the ethanol was used to replace furfural alcohol partly. Thestrength of the resin of24h was2.18MPa. By agent J, the free formaldehyde content waslowed under0.1%to meet the requirement of environment.In the end, the mechanism of modification was analyzed and some processperformance of the furan resin was tested by experiment. The furan resin prepared in this paper has a high-strength, a low odor, a low cost, andit will promote the wide application of furan resin to creat considerable a economic benefitand a high social benefit in the future.