In situ synthesis and preparation of TiO2/polyimide composite containing phenolphthalein functional group

In this paper, titanium dioxide (TiO 2 )/phenolphthalein-type polyimide (PPPI) composite was synthesized in situ polymerization, the diamino phenolphthalein type compound and dimethylacetamide as the matrix, and TiO 2 as the filler. The mechanical property and thermal conductivity properties were used to characterize the properties of the obtained composite. A diamine monomer containing more benzene rings of phenolphthalein and an ether bond in its main chain were prepared, synthesized by a nucleophilic substitution reaction and a hydrazine hydrate reduction reaction. Polyimide composite had the same structure as that of a diamine monomer. And it was synthesized by solution imidization and heat imidization. The results showed that TiO 2 improved the dispersibility, alignment and interfacial strength of the TiO 2 /PPPI composite. The mechanical property of polyimide composite was increased with the increasing TiO 2 loading. And a suitable addition of TiO 2 could enhance the mechanical properties of polyimide system. Compared to polyimide resin, the TiO 2 /PPPI composite had a higher thermal conductivity with the increasing of TiO 2 content. All of these changes in properties were closely correlated with the TiO 2 /PPPI composite, which could form an interaction interface structure in the system.