Organosilicone modification polyurethane elastomer and preparation method thereof

Abstract

The invention relates to an organosilicone modification polyurethane elastomer and a preparation method thereof. The method comprises the steps that firstly, silicones at the carbon function hydroxylsealed end are adopted as a flexible chain and subjected to bulk polymerization with polyisocyanates under the solvent-free state, and therefore the mechanical property of the elastomer is improved; then, a certain amount of organic solvent is added to the chain extension stage for attenuation, a catalyst is used, the compatibility and viscosity of the system are effectively balanced, macroscopicincompatibility is avoided so as to ensure smooth conduction of the reaction, and a high molecular weight polymer with the large viscosity is generated. The method can obtain the elastomer with the good transparency and glossiness, meanwhile, due to the fact that the catalyst is added into the chain extension stage, the chain extension speed under the solvent is increased, the reaction time can begreatly shortened, the reaction efficiency is improved, and side reactions are avoided.

Description

technical field [0001] The invention relates to a silicone-modified polyurethane elastomer and a preparation method thereof, belonging to the technical field of synthesis of silicone polymer materials. Background technique [0002] Silicone materials have a series of advantages such as excellent physiological inertia, high and low temperature performance, hydrophobicity, weather resistance and good biocompatibility. Combining silicone materials with polyurethane materials will endow polyurethane with excellent high and low temperature resistance and water resistance. Among them, introducing polysiloxane into the main chain of polyurethane molecules is one of the most common methods. However, due to the large difference in solubility parameters between polysiloxane and polyurethane, it has brought difficulties to polysiloxane modified polyurethane, especially for high molecular weight polysiloxane, the molecule is more non-polar and reactive. It is also smaller, and the pre...

AI Technical Summary

Problems solved by technology

However, the physical blending of polysiloxane and polyether or polyester polyol into soft segment modified polyurethane has the following disadvantages: the reaction rate between polyether polyol or polyester polyol and isocyanate is relatively fast, and isocyanate preferentially reacts with polyether polyol Or polyester polyol reaction, and then react with polysiloxane, which is easy to cause irregular structure of the generated polymer, unstable performance, and polysiloxane is not easy to react completely

Both steps adopt the bulk method to prepare elastomer, which has good heat resistance and hydrolysis resistance of polysiloxane, but its mechanical properties are poor, and it is difficult to further react when the viscosity is high in the chain extension process, and the reaction is not easy to be complete. Therefore, it is impossible to guarantee that the reaction will generate a polymer with a larger molecular weight and better mechanical properties, especially for adding a solid trifunctional chain extender after the preparation of the prepolymer, it is more difficult to mix evenly under the condition of bulk chain extension, which will affect the reaction.

[0005] Some literatures have reported the preparation methods of other silicone-modified polyurethane elastomers, that is, reacting in the solution by one-step method or prepolymerization method. The degree of microphase separation of the elastomer prepared by this method is small, resulting in low mechanical properties. The solution polymerization method reported in Journal of Polymer Science: Polymer Physics Edition, Vol.23, 2319-2338 (1985) to prepare silicone-modified polyurethane elastomers has a tensile strength of only 2.4-5.0MPa

Images