| The addition between siloxane with Si-H bond and unsaturated compound is one of the most important reactions in organic chemistry, which plays a significant role in industry.Futhermore, the homogeneous Pt complexes are the commom catalysts for hydrosilylation,but due to their homogeneity, difficulties of separating from the reaction system and bad impacts on the product properties when they remained in the product, the application of this kind of catalysts have been restricted in industry. To conquer this difficulty, heterogeneous platinum catalyst were studied in this paper. The heterogeneous catalysts can be prepared easily and it have been tested the catalytic performance in the reaction of HDE and MDHM.Finally, every kind of performance of catalytic product are obtained. The primary results can be summarized blow.1.The mesoporous Pt/Si O2 catalyst could be prepared by one-step method, using dodecylamine(DDA) as the template, tetraethyl orthosilicate(TEOS) as the silicone source,Speier catalyst as the platinum source, and characterized by FTIR, UV-Vis, BET and XRD and the Pt content of the catalyst was confirmed by ICP-AES, the results turned out that Pt was supported on Si O2 successfully and the Pt content of the catalyst was 18.735 ppm.2. The hydrosilylation of systhesis of synergistic agent(HDM) from polyoxyethylene alkyl allyl ethers(HDE) with average molecular weight of 380 and heptamethyltrisiloxane(MDHM), was catalyzed by Pt/Si O2 under N2 atmosphere. The structure ofcatalytic product was verified by fourier transform infrared spectroscopy(FTIR) and proton nuclear magnetic resonance(1H NMR). The synthesis of HDM was optimized by the single factor experiment,it was found that the optimal conditions at which the conversion of MDHM(93.7%) was obtained: the reaction malor ratio of HDE and MDHM 1.0:1, reaction of temperature and time were 100℃ and 3.0h, respectively, the Pt content was 14.232 ppm. Furthermore, the conversion of MDHM was still more than 80% when Pt/Si O2 was used seven times. It was verified that it was the platinum which was supported on mesoporous channel to catalyze the hydrosilylation, which was determined as the second-order kinetic order law and the activation was 73.56 k J/mol. Many indicators of HDM aqueous solution was tested, such as the CMC, contact angle, cloud point and so on, the hydrolysis of the aqueous solution ofHDM at p H=3,7,11 was also studied, and found that the properties of HDM aqueous solution was superior to the reference sample(Silwet).3. The Pt/Si O2/CS catalyst was synthesized by the Si O2/CS carrier obtained through CS modifying Si O2, supporting platinum. And it was characterized by FTIR, TG, BET and UV-Vis, and found that platinum was supported on the carrier successfully, and the Pt content was 0.6554wt%.4. HDM was obtained by the hydrosilylation of HDE and MDHM catalyzed by Pt/Si O2/CS and characterized by FTIR and 1H NMR to confirm the structure of HDM. The synthesis of HDM was optimized by the single factor experiment, it was found that the optimal conditions at which the conversion of MDHM(94.8%) was obtained: the reaction mass ratio of n(HDE): n(MDHM)=0.9:1, reaction of temperature and time were 95℃ and3.0h, respectively, the Pt content was 0.43wt%. After being used eight times, the Pt/Si O2/CS catalyst was verified to remain high activity. According the second-order kinetic law, the activation energy of the hydrosilylation reaction was 71.83 k J/mol. And it was found that the properties of HDM was superior to the reference sample(Silwet) at the property test. |
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