| Polyimide adhesive is a kind of very important polyimide adhesives, which has high temperature resistant adhesives because of its good anti-high temperature and anti-radiation and anti-corrosion. It has high chemical stability, good dielectric properties and mechanical properties, and is widely used in aerospace, satellite communication, nuclear power, electrical insulation, microelectronics industry, and other areas of the tip. In this paper, we are on the basis of predecessors’ research adopts the method of binary polymerization to the preparation of the performance. At the same time it has a low cost of polyimide adhesives.Trimellitic anhydride chloride (TMAC) and 4’4-diamino diphenyl methane (MDA) as monomers, it examines the different mole ratio, reaction temperature, solid content and the presence of end capping agenton the structure and properties of polyamide acid, and by using FT-IR, TGA, DSC, viscometer and rotary viscometer were analyzed. Results show that the raw material monomer has indeed polyamide acid which has been synthesized, the structure and properties of polyamide acid as the change of different factors present a certain rule, from the viewpoint of energy consumption, product performance, etc, such as mole ratio,0℃,30% solid content under the condition of reaction synthesis of polyamide acid is the most suitable for the following research and amination.Equivalent mole ratio,0℃,30% solids reaction under the condition of polyamide imide acid in gradient, and process condition of 100℃ 1h+160℃2h+220℃3h, and by using FT IR, TGA, DSC, viscometer and rotary viscometer has been analyzed. It has been found to generated the polyimide and its glass transition temperature of 293.34℃, the thermal decomposition temperature is 650℃. The polyamide acid (50℃) from low temperature to high temperature (250℃), of thermal to inspect the amination, the results show that the above 160℃ has an apparent cyclization, and the higher temperature, the longer heating time, the greater degree of amination. In 250℃, reaction after 4 h, the amination has been leveled off, maximum of 84.08%.For polyamide acid from low temperature (60℃) to high temperature (170℃), and diluted into different solid content in solution, of thermal and FT-IR analyzes, its characteristic is viscosity. Results found, and comparison of thermal, the amination can get very good control, and obtain the same degree of amination need less energy consumption, characteristics of polyimide is lower viscosity.We use acetic anhydride+triethylamine as catalyst of polyamide acid (volume ratio of 2:1) chemical and animation. With different catalyst content, different temperature, the influence of different solid content on the animation, and analysed using FT-IR characterization, it is found that the animation present some regularity in under the influence of different factors, the greater content of catalyst, the higher temperature, solid content, the greater degree of animation is the major factor, but the catalyst content even if the temperature is very low (50℃), high solid content (20%), when acetic anhydride:PAA and the molar ratio of 4:1, which is close to the amination completely; it is much more easier to control the amination degree.Adopting the method of single lap joint tensile shear testing the bonding performance of polyimide adhesives, we examine the different solid content, curing process, the surface roughness and end capping agent content on the influence of the bond strength. The results found that when the gel contains no-end capping agent liquid solid content reaches 25%, it has good adhesive performance. Using 800 # rubber sheet of sand paper burnish, curing process 100℃1h+160℃2h+250℃3h can achieve the best technological conditions of adhesive performance. |
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