| With the development of economy, the organic silicon resin is used more widely, especially the application of high temperature resistant anticorrosive coating, which is widely applied in electronics, light industry, chemical industry, military project, aerospace and other fields. Because the heat resistance of ordinary silicone resin hasn't already been able to meet the requirements needed, it is urgent to seek new high temperature resistant resin, but have Ti-O(662.0kJ·mol-1) of the silicone resin containing titanium can meet the requirements.This paper describes firstly the synthesis of titanium-containing silicone resin, the synthesizing methods of which include condensation, catalyzed addition, and peroxide oxidation method. This paper takes the method of condensation, taking the methyl triethoxy silane, dimethyl diethoxy silane and phenyl triethoxy silane as the raw materials, hydrolyzed under certain conditions, and taking butyl titanate as titanium source, and then titanium-containing organic silicone resin is formed through hydrolysis condensation. The optimal reaction conditions gained by study are as follows: R / Si = 1.44, Ph / R = 0.21, hydrolysis temperature 65 ?, the catalyst HCl. The structure of titanium-containing organic silicone resin can be characterized by infrared spectra, and the heat resistance can be detected by TGA.Secondly described is the synthesis of unsaturated polyester resin. Its materials include trimethylolpropane, diethylene glycol, neopentyl glycol, adipic acid and isophthalic acid, through which the new-type end hydroxyl saturated polyester resin is synthezied. Saturated polyester can control the adhesion, hardness and solvent resistance properties of the coating, and it is compatible well with a variety of resins. In addition, the intermolecular forces between the resins, such as hydrogen bonding, van der Waals molecules, will facilitate molecular mutual solution. The functional group of two resins has certain reactivity under test conditions, promoting the formation of uniform molecular compatibility between molecules. These are the reasons why saturated polyester are widely used.On the basis of the titanium-containing silicone resin and end hydroxyl saturated polyester which have been synthesized, there are two modified routes of blending and copolymerizing to complete the modification of end hydroxyl saturated polyester by the titanium-containing organic silicone resin. According to the infrared spectrum of the copolymerization modified polyester, the oxethyl disappearance can be found, meanwhile, the weight-average molar mass increases, which indicates that the titanium-containing organic silicone has been grafted onto the polyester resin. By thermogravimetric test, chemical resistance and other tests, it is found that the modified polyester copolymer outperforms blending polyester.When the mass ratio of titanium-containing organic silicone resin and unsaturated polyester is 1:1, with a polyisocyanate as a curing agent, after the copolymerization, there will be solidified film on the tinplate with coating hardness of 5H, adhesion grade 1 resistance, boiling water resistance 5h, the impact strength greater than 50 kg ? cm, and good acid and alkali resistance, heat resistant temperature up to 400 ?. According to the electron microscope analysis, the enhancement of coating properties may be due to the jointing onto polyester of titanium-containing organic silicone polyester segments, which improves the degree of crosslinking, so that the surface becomes compact and uniform.Because the end hydroxyl saturated polyester modified by synthetic titanium-containing organic silicone resin has good mechanical properties, heat resistance, weather resistance, corrosion resistance and other properties, it can be used in the nuclear industry, boilers and high temperature reaction equipment, preventing the thermal oxidation corrosion of metal under high temperature conditions, so as to extend the service life of the equipment. |
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