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Jul 21, 2023
Blending modification is simple physical mixing without Chemical bond formation. Due to the significant difference in dissolution parameters between organic silicon compounds and polyurethane compounds (7 5 and 10. 0), the resins have strong immiscibility, resulting in severe phase separation and low mechanical properties of the modified mixture. Therefore, there is currently relatively little research on physically modified polyurethane. The properties of the mixed solution and film of polydimethylsiloxane waterborne polyurethane and different types of soft segment waterborne polyurethane were studied The contact angle was studied and it was found that when PDMS-PU was mixed with acyl or ester type soft segment WBPU, the solution particles increased with the increase of PDMS-PU content, and with the increase of PU-PDMS content, the mixture particles also increased, larger than pure WBPU particles. With the increase of PDMS-PU content, the contact angle of each mixed WBPU to the fiber decreased, while the contact angle to water increased. The study also found that the surface silicon content of WBPU mixed with PU PDMS was close to that of a single PDMS The silicon value of PU.
It can also be modified by physical blending of waterborne polyurethane dispersion and organosilicon lotion. Polyurethane can improve the oil resistance and non-polar solvent resistance of polysiloxane lotion, while polysiloxane lotion can improve the water resistance and solvent resistance of waterborne polyurethane. The blending of the two can achieve the effect of learning from each other. When organic functional silane is added to the waterborne polyurethane lotion, the silane can hydrolyze with the moisture in the environment. On the one hand, the formed silanol can continue to undergo condensation reaction, thus forming Covalent bond to form cross-linking. On the other hand, it can also form Covalent bond with the hydrolysis groups on the surface of a variety of substrates, such as glass, concrete and gold. Due to its inherent hydrolysis sensitivity, traditional silicone esters are prone to pre crosslinking reactions in aqueous systems, which limits their further application.
The waterborne polyurethane modified by epoxy siloxane is a hydrolytic Condensation reaction reaction between the epoxy group in the crosslinking agent and the alkonyl or alkonyl quaternary salt group in the waterborne polyurethane and the siloxane group. Lion group plays a key role in the cross-linking reaction system, and water plays an important role in the Condensation reaction system. The solvent type without water can not undergo crIn recent years, the Organic Functional Silane Department of Compton Limited in the United States has developed a series of silanes with spatial hindrance structures, which can be applied to water-based systems by controlling their hydrolysis sensitivity, thus avoiding various adverse situations mentioned above. These new silanes are designed to have structures with larger alkoxy groups, reducing the tendency for hydrolysis. It exhibits excellent long-term storage stability in water-based systems, with good adhesion and physical properties even after being stored at room temperature for more than 1 year. Therefore, a single component water-based formula can be achieved. And avoided various unfavorable situations mentioned above. These mixtures can be cured with the combination of lotion, and can also be used as low energy crosslinking agents to accelerate the curing through the use of catalysts.oss-linking reaction. The obtained coating has good resistance to water and organic solvents. At the same time, it has the characteristics of low curing temperature, non-toxic, and safe use.
Compatibility of polyurethane and epoxy silane
There is Chemical bond cross-linking between polyurethane and epoxy silane, and the Chemical bond cross-linking between the two phases in the blend system is conducive to improving the compatibility between the two phases and stabilizing the blend system. In this system, the tibial group formed by ring opening of epoxy group and Carbamate group on polyurethane may also form hydrogen bond to some extent, and the existence of hydrogen bond is also an effective means to improve compatibility.
Researchers studied the blending modification of tibia terminated polydimethylsiloxane with alcohol hydrolyzed hemp oil modified polyurethane prepolymer. It is found that after the copolymer film is formed, the organosilicon segments in the molecular structure are more inclined to the surface enrichment orientation, while the polyurethane segments are oriented towards the inner layer, which keeps the low surface energy properties of the organosilicon segments, improves the hydrophobicity of the copolymer products, and improves the adhesion, hardness, curing speed and other mechanical properties of the copolymer film. In addition, the properties of silicone modified polyurethane coating were also studied. It was found that with the increase of the content of polyorganosiloxane in the blend, the dispersion component of the surface energy of the coating and the polar separation decreased. At the same time, the polyorganosiloxane with low surface energy increased the contact angle of the coating with water and sodium alginate.
Our main products are Acrylic Modified Silicone Resin Emulsion，Epoxy Modified Silicone Resin Emulsion，Smokeless Silicone Resin，Self-drying Silicone Resin，Highly Active Silicone Resin，Methyl Silicone Resin Intermediate.