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Poly(imide siloxane), block and blend copolymer, were synthesized using different methods to explore the influence of siloxane chains. The flexible siloxane chains enrichment on surface of copolymer, enhance hydrophobic and adhesive with copper foil. It also improves light transmittance of polyimide film in the visible light region. The effect of different preparation methods on the aggregation in polymers and on polymer properties, especially adhesion and water absorptivity, are also discussed. The imidization temperature and synthesis method (blend and block) during the reaction has a significant effect on the properties of the product, especially thermal properties (T g values are 207 C for block and 180 C for blend) and mechanical properties (elongation of 130% for block and 50% for blend). The bonding strength of polymer films used as hot melt adhesive was also tested.

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Limitations in the properties of polyamide PA66, such as low glass transition temperature and high water absorptivity, limit its applications. Introduction of amorphous polyimide segments into the PA66 main chain lowers the glass transition temperature and melting temperature and also improves its processability. PA66-polyimide (PA-PI) copolymers with different weight ratios of PI are prepared by high temperature and high-pressure solution polymerization. The degree of crystallization of PA-PI copolymers decreases with increasing PI content. The melting point decreases from 261 C for PA66 to 223 C for PA-PI-4. Dynamic mechanical analysis shows that the T g increases from 70 to 90 C, and the storage modulus can be well maintained. Rheological studies show that the temperature for processing can reach 70 C. Copolymers with different PI contents show different processing viscosities. In addition, water absorptivity (about 1.8%) and dielectric constant values of PA-PI and PA6/6T are similar.