Controlled coagulation of rigid-chain polymer thin films

摘要

A method for preparing optical quality, thin films of rigid- rod polymers and co-polymers, as well as blends of such polymers or co- polymers with flexible coil-like aromatic heterocyclic polymers and co- polymers which comprisesPP(a) preparing a solution of the rigid-rod polymer or co-polymer or blend in a suitable solvent;P P(b) forming a film from the solution;PP(c) exposing the film to a non-solvent vapor for about 1 to 5 minutes per micron thickness in the finished film; andPP(d) coagulating the film in a non-solvent.PPThis method can be employed to prepare films of high nonlinear optical susceptibility for electro-optical device applications. Because of their thermal stability, mechanical strength and chemical resistance, films prepared according to this method can also be used as filters and separation membranes.