There are majority ways to design polymeric materials including the synthesis of polymers with molecular weights in a given range and their modification with different nanoparticles to create composites. Due to this, the synthesis of a novel catalyst based on a copper thiadiazol complex for the ATRP polymerization to develop polystyrene (PS) and metal-organic framework (CrMOF, accepted abbreviation MIL-101) based on chromium (III) and trimesic acid by a novel approach was carried out to obtain novel composite material. The developed PS and PS/CrMOF composite were applied as membranes in pervaporation for the hydrazine concentration to evaluate their potential use as membrane materials. The structural and physicochemical properties of synthesized substances and developed composites were studied by various analysis methods.