Study On The Waterborne Polyurethane Made From Maleic Anhydride Modified Castor Oil

Waterborne polyurethane is a kind of important polymer. It has replaced solventborne polyurethane in adhesive, coating and other fields to meet the need of environmental protection in recent years. With the time going into 21 century, the petrochemicals are becoming in short, people attempt to introduce natural resources into polyurethane, and thus a series of new polyurethane materials appear.In this paper, we synthesized a kind of polyurethane filling retanning agent by maleic anhydride modified castor oil (MCO) through molecule design. An optimized recipe was selected through studying the emulsion and application properties of the filling retanning agents made from different synthesis recipes. Control studies among the product MC-PURF made from this recipe and the general products of domestic and overseas showed that this product has better filling property and good sunshine resistance.Waterborne polyurethane has excellent physical-mechanical properties, cold hardiness, elasticity and gloss, but poor in water resistance and strength. In order to overcome their shortcomings, researchers all over the world have been working in the basic theory and modification of waterborne polyurethane.Waterborne polyurethane dispersions (MCPU) with ionic groups in the soft segments were synthesized use MCO as polyol according to prepolymer mixing process. The studies on the properties of dispersions and their films showed that: phase mixing between soft and hard segments increased with increasing of m (MCO)/m(Polyether Ng210); with the increasing of n(NCO)/n(OH), the thermostability of MCPU films increased, the hardness and tensile strength of MCPU films increased, the elongation at break of MCPU films decreased, the film's resistance to solvent increased; when the hydroxyl value of MCO was 2.2, we got MCPU film with higher tensile strength and elongation at break.The optimized synthesis conditions for the preparation of polyurethane-polyacrylate (MCPU-PMMA) hybrid, using MCPU dispersion as seed emulsion to copolymer with methyl methacrylate (MMA), were determined. The hybrid will have better compatibility, higher stability and film with excellent properties when introducing more unsaturated groups into polyurethane component through studying the properties of MCPUs-PMMA hybrid and film made from MCO with different hydroxyl value.