Synthesis And Properties Of Aluminum-containing Silicone Polymers

Compared with traditional organosiloxane materials,silsesquioxanes have been applied in many fields due to their special spatial configuration and easy to design molecular structure.At the same time,the metal element is modified into organosiloxane,and the obtained polymetalsiloxane will change the properties of the organosilicon compound significantly,mainly in temperature and weather resistance,dielectric properties and reaction.In terms of activity,etc.,it has gradually become a hot spot of silicone in recent years,but the polymetallic organosilicon compounds synthesized at present are mostly linear oligomers.In this study,based on the synthesis of clathrate phenyl silsesquioxane,by double degradation Method:A trapezoidal polyaluminum phenylsilsesquioxane was prepared by inserting aluminum into the molecule,and a caged polyaluminum phenylsilsesquioxane was prepared by inserting aluminum into the molecule by a capping method.They are blended with polyurethane to prepare composites for modification.The specific research contents are as follows:First,the phenyltrichlorosilane was hydrolyzed and condensed to prepare a cage-shaped phenyl silsesquioxane.The preparation process of clathrate phenyl silsesquioxane was investigated.It was found that an appropriate amount of catalyst can greatly accelerate the reaction of catalytic rearrangement,and the catalyst dosage is preferably 0.2%.The reaction length of the base-catalyzed rearrangement can increase the degree of catalytic rearrangement,and the duration is 12h.The increase of the reaction temperature of the base-catalyzed rearrangement affects the activity of the reactants.When the temperature is higher than 100 C,the product does not change substantially.Therefore,the reaction temperature is preferably set at 90-100 ?.A series of measurements were carried out on the spatial structure and properties using infrared spectroscopy(FTIR),nuclear magnetic spectroscopy(Si NMR),nuclear magnetic spectroscopy(CNMR),scanning electron microscopy(SEM),elemental analysis and molecular weight test(GPC).Weight loss(TGA)focuses on its heat resistance.The results show that the initial decomposition temperature is 437? in nitrogen atmosphere,the residual carbon rate at 800? is 73.85%,the residue is black;the initial decomposition temperature in air is 442 ?,and the residual carbon temperature at 800 ? is 44.30%.The residue was white silica,indicating that the cage-form phenylsilsesquioxane formed by the reaction was superior in resistance.Secondly,on the basis of the synthesis of clathrate phenyl silsesquioxane,the Al element was successfully introduced into the silsesquioxane molecule by a double degradation method,and a trapezoidal phenyl polyaluminum silsesquioxane was synthesized.A series of characterization studies on its structure and properties,and the heat resistance of trapezoidal polyaluminum phenyl siloxane was studied.The high temperature residual carbon ratio in the nitrogen atmosphere at 800? was 55.16%,and the high temperature residual carbon ratio in the 800? air atmosphere was 32.59.%;then using the apex cap method,first open the cage phenyl silsesquioxane,then introduce the Al element into the clathrate phenyl silsesquioxane molecule to study its properties,the polyaluminum clathrate benzene The high temperature resistance of the silsesquioxane is excellent.Compared with the clathrate phenyl silsesquioxane,the addition of Al element greatly improves the heat resistance,and the initial decomposition temperature in nitrogen rises from 437?.At 528?,the high temperature residual carbon rate at 800?increased from 73.85%to 75.38%.The initial decomposition temperature in air increased from 442? to 470? to 800? high temperature residual carbon rate from 44.30%to 55.03%.Finally,the polyurethane was blended and modified with caged phenyl silsesquioxane,trapezoidal polyaluminum phenylsilsesquioxane,and caged polyaluminum phenylsilsesquioxane,respectively.The effect of heat resistance.The results showed that the initial decomposition temperature of the system was increased from 268 C to 290 C by adding 5%by mass of the phenyl-silsesquioxane polyurethane.The residual carbon ratio of the polyurethane was increased from 3.48%to 10.09%.%mass fraction of trapezoidal polyaluminum phenylsilsesquioxane polyurethane,the initial decomposition temperature of the system increased from 268? to 293?,the residual carbon ratio of polyurethane increased from 3.48%to 5.23%,adding 5%by mass The polyurethane of the caged polyaluminum phenylsilsesquioxane increased the initial decomposition temperature of the system from 268? to 300?,and increased the residual carbon ratio of the polyurethane from 3.48%to 12.98%.