| Borate ester is a kind of important boron compound and is widely used in many respects. It can be not only used as polymer additives, gasoline additives and flame retardants; but also can be used as a corrosion inhibitor in anti-rust and anti-corrosion processing of steel materials. At the same time, long chain fatty acid amide borate esters and aromatic compounds of borate ester as a special surfactant are researched in-depth. Due to our country has abundant boron resources, especially in Liaoning province. To make the fullest use of these valuable resources, the further study of borate ester has important practical significance.In this paper, a new type of borate ester, which contains nitrogen with lone pair electrons to avoid the nucleophilic reagent such as water molecules attacking the empty orbital of boron atom, was synthesized. The hydrolytic stability of borate ester can be improved under the condition of nitrogen atom and boron atom forming N'B coordination bond.Firstly, the amide intermediate, i.e.fatty acid diethanolamide, was synthesized by using two-step synthesis method and then the intermediate product reacts with boric acid to synthesize fatty acid diethanolamide borate ester. In addition, triethanolamine borate ester was synthesized by using triethanolamine and boric acid as materials. The effects of boric acid to triethanolamine molar ratio, reaction temperature and reaction time on the synthesis of triethanolamine borate ester were investigated, respectively. And the suitable synthesis parameters were obtained:boric acid to triethanolamine molar ratio1:1.2, reaction temperature145℃, reaction time4h. The synthesized borate esters were characterized by IR Spectrum and the hydrolysis stability of the product was also investigated. The results indicated that the hydrolytic stability of the product was improved greatly due to inter-molecular-coordination of nitrogen with boric in borate ester.The antirust property of borate esters was tested by using45#steel as test blocks. The test blocks of45#steel were immersed in0.5%fatty acid diethanolamide borate solution with dispersant for10d, no rust was observed on the test blocks. In addition, the test blocks of45#steel were immersed in0.5%trithanolamine borate solution for10d, no rust was observed on the test blocks; the test blocks of45#steel,20#steel and cast iron were immersed in2.5%trithanolamine borate solution for30d, no rust was observed on the test blocks. The results indicated that borate esters have excellent antirust function. Fatty acid diethanolamide borate ester was used to modify brucite by wet method as surfactant. The results indicated that the activation index of the modified brucite, which was modified at75℃and4.5:1of liquid to solid ratio for70min with adding5%oleic diglycolamide borate, can reach to98.87%. In the same way, when brucite was modified at65℃for65min with the liquid to solid ratio of4.5:1by adding5%lauric diethanolamide borate ester, the activation index of brucite can reach to75.69%. The modified brucite and unmodified brucite were respectively characterized by IR, SEM, XRD, particle size distribution and TG/DTG, the results showed that borate ester was just covered on the surface of brucite, and the morphology and crystal structure of brucite had no obvious change after the modification. The particle size of modified brucite decreased obviously and the coarse surface of modified brucite was formed after the modification, besides the dehydration temperature of modified brucite was tested between300-400℃.In addition, the modified brucite was filled into Ethylene-Vinyl Acetate (EVA) as a kind of fire-retardant and the effect of modified brucite addition on the properties of EVA/brucite composite material was studied. With the flame retardant addition increasing, the breaking elongation and tensile strength of EVA/brucite composite materials tended to decline, however the flame retardant effect was strengthened obviously. |
PDF Full Text Request