Abstract:

Polyimide (PI), a type of high temperature-resistant polymer synthesized using dianhydride or diamine, has become one of the most industrialized polymer materials with the highest operating temperature owing to its strong high-temperature resistance property. However, the strength of PI films still needs to be improved for their industrial application. To improve the elongation rate and tensile strength of PI films, different methods, such as adjusting the concentration, ratio, addition method of precursors and the addition amount of biomass fibers, have been tested in our experiments.4,4-Diaminodiphenyl ether and 3,3,4,4-biphenyltetracarboxylic acid dianhydride were used as the precursors for the reaction. Polyamide acid was prepared using the positive addition method in the presence of a cross linker, which was then poured into a Petri dish containing uniform lotus root fiber. The PI film was obtained by calcination. The results showed that the final gage length and elastic modulus of the PI films containing lotus root fiber were lower than those of the pure PI film. Furthermore, PI-2% root-fiber film had a tensile elongation at break of 6.49%, a tensile strength of 67.33 MPa, and a maximum force tolerance.of 57.47 N, which are much higher than those of pure PI film. Thus, the addition of lotus root fiber enhances the mechanical properties of the film.

Key words: polyimide film, biopolymer fiber, tensile property, lotus root fiber