| The main application of high-temperature adhesive is in bonding of high temperature materials, which is an effective way to bond and seal the high-temperature materials. High-temperature adhesive is generally used in high-tech fields of aviation, aerospace and war industry. By using high-temperature adhesive, the bonding problem of high temperature material could be effectively solved. Usually high-temperature adhesive has the disadvantages of high curing temperature and bad high temperature capacity. In order to further improve the heat resistance and mechanical strength of high temperature adhesive, high temperature adhesive is prepared by using the method of inorganic filler added into organic resin. On the theoretical basis of low-temperature phase by resin and high temperature phase by inorganic fillers, this paper carried out the following research:1. Using organic silicon resin, which has excellent heat resistance in organic resin, as the adhesive main ingredient. Then epoxy resin was added to the organic silicone resin to change its nature and the modified resin may be cured at room temperature. By orthogonal experiments, when m (epoxy resin):m (silicone resin)= 3:7, the adhesive strength is maximum. In the synthesis process of modified resin, the dosage of silane coupling agent KH-560 is 2%. In the adhesive curing process, the dosages of organotin catalyst and low molecular weight polyamide curing agent 650 are 0.3% and20%. The prepared adhesive may be cured at room temperature for 48 hours; shear strength can be up to 33MPa.2. In order to further improve the adhesive bond strength in high-temperature environments, the adhesive added inorganic pigment fillers Al, B4C and ZrO2. Discussed the effect of a single component for the heat resistance of the adhesive; and studied how the matched active fillers Al and B4C affecting the adhesive properties. Further, it studied the best ratio of active and inert pigment fillers. Eventually obtained that m (Al): m (B4C):m (ZrO2)= 3:7:2.5; the organic resin/inorganic pigment filler mass ratio is 1:1; the compression shear strength of adhesive is 16.62MPa after 1000℃ high temperature treatment. Then, it analyzed the chemical resistance and the linear rate of change of this high temperature adhesive. Found that this high temperature adhesive has good chemical resistance and of the worst corrosion in the acidic environment; the linear change of this adhesive is shrinkage in the macroscopic under high temperature conditions, but the shrinkage is small and the maximum linear shrinkage occurs at 800℃ conditions, which is of 12.1%.3. Add SiC whiskers as reinforcement, prepared composite high temperature adhesive. After testing and analyzing, it can be obtained that the optimum dosage of whiskers is 2%. Whisker improved the bonding strength of high-temperature adhesive at the same temperature. After 1000℃ high temperature treatment, the mechanical strength can reach to 20.2MPa, and the bonding strength increased 21.5% compared to adhesive without whiskers.4. Studied the adhesion properties of COPNA resin adhesive. Mainly through the analysis method such as IR, TG, SEM, analyzed the heat weight-loss, the types of functional group and other respects of COPNA resin, which is as high-temperature adhesive. Meanwhile, added inorganic pigment fillers into COPNA resin:Al powder and B4C powder. The results can be obtained:when inorganic pigments fillers are added, the performance of COPNA resin adhesive has been greatly improved; when pigment fillers is amount of 60% of the total mass of the adhesive, COPNA resin adhesive is of the maximum adhesive strength on hot environment. |
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