Preparation And Properties Of Polyurethane Composite Memberane Modified By Graphene

Graphene is considered the monolayer carbon atoms of two-dimensional slice layer honeycomb lattice structure of new materials, and it has found the most thin and rigid inorganic nanomateria in the world. Meanwhile, it enjoy other nanomaterials could not possess excellent properties, such as excellent electronic, mechanical, heat and photoelectric properties. However, synthesis of graphene and its application in most polymer have encountered a lot of problems, because of the laminated structure is easy to gather together a widespread reunion, and it has resulted in a uniform dispersion of graphene in polymer matrix is very poor. How to solve the graphene dispersed in polymer matrix, and improve the graphene layers structure and interface combined with polymer matrix problems. The results show that it is the scientific community has been trying to solve the problem. This dissertation aimed at these problems, a large number of graphene was synthesized with chemical method, through the nanocrystalline cellulose assist dispersion reduction of graphene oxide, made uniform and stable graphene layer structure of water dispersion. Then using the method of solution blending and realized with graphene in the process of preparation for the reunion of control, the preparation of high-performance polyurethane nanocomposites. It will be in biological medicine, electronic, pressure sensor has potential application value. In this paper the research content is as follows:(1) We use the modified Hummers method that prepared graphene oxide. By hydrazine hydrate reduction preparation of graphene. Characterization structure and properties of graphene and graphene oxide by Electron microscopy, Raman spectroscopy, Fourier infrared, X-ray diffraction and Elemental analysis and so on.(2) Through the self-made nanocrystalline cellulose auxiliary dispersed reduction graphene oxide, and made dispersed uniformly and stable graphene/nanocrystalline cellulose water dispersion. Then using the method of solution blending preparation of high conductive polyurethane composite membrane. Nanocrystalline cellulose auxiliary graphene dispersion was studied in aqueous polyurethane problem of matrix. When the graphene quality percentage is 3.0wt%, The nanocomposite membrane conductivity reached a maximum of 4.24×10-3Scm-1. The graphene/nanocrystalline cellulose/waterborne polyurethane conductive composite membrane may be potential application in pressure sensors, medical equipment.(3) Through the self-made nanocrystalline cellulose auxiliary dispersed reduction graphene oxide, and made graphene/nanocrystalline cellulose composite powder. And using N,N-dimethyl formamide solvent, the graphene/nanocrystalline cellulose compound dispersoid is good dispersion. Then evenly dispersed graphene and polyurethane blended. Using wet film, the preparation of the graphene/nanocrystalline cellulose/polyurethane composite porous membrane. Graphene/nanocrystalline cellulose composite dispersion are added to improve the performance of composite porous membrane appear, meanwhile it gives the composite porous membrane conductivity. But its mechanical properties decreased. We will improve in polyurethane porous membrane permeability, but the composite porous membrane will not significantly reduce polyurethane porous membrane mechanics performance research.