Soft segment cross-linked thermoplastic polyurethane elastomer and preparation method thereof

Abstract

The invention belongs to the technical field of thermoplastic polyurethane elastomers, and particularly relates to a soft segment cross-linked thermoplastic polyurethane elastomer and a preparation method thereof. The soft segment cross-linked thermoplastic polyurethane elastomer is prepared from the following raw materials in percentage by weight: 50 to 70 percent of dihydric alcohol, 22 to 38 percent of diisocyanate, 6 to 10 percent of chain extender, 0.1 to 0.8 percent of trihydric alcohol, 0.1 to 0.5 percent of bulking agent, 0.1 to 0.5 percent of antioxidant, 0.1 to 1 percent of light stabilizer, 0.5 to 1 percent of lubricating agent and 0.002 to 0.02 percent of catalyst. The synthesized polyurethane elastomer contains a certain amount of soft segment chemical crosslinking, the compression deformation of the product can reach 20-25%, the light transmittance can reach 91% or above, and the softening temperature is increased by 20-30 DEG C compared with a conventional system. The preparation method is simple and easy to implement, the melt viscosity is stable and controllable, and the method can be widely applied to the fields of oil seals, trundles, shoe materials, high-temperature oil pipes and the like.

Description

technical field [0001] The invention belongs to the technical field of thermoplastic polyurethane elastomers, and in particular relates to a soft-segment crosslinked thermoplastic polyurethane elastomer and a preparation method thereof. Background technique [0002] Thermoplastic polyurethane elastomers are usually linear materials, which can be melted by heating and shaped by cooling, and can be repeatedly processed and reused by extruders, injection molding machines and other equipment, and the processing method is simple and easy. Compared with thermosetting polyurethane elastomers, thermoplastic polyurethane elastomers have obvious advantages in terms of processing and environmental protection, but have obvious disadvantages in terms of material heat resistance, resistance to compression deformation, and transparency. [0003] CN 104017166 A discloses a preparation method of high temperature resistant thermoplastic polyurethane elastomer, which uses small molecule trihyd...

AI Technical Summary

Problems solved by technology

[0005] At present, the research on thermoplastic polyurethane elastomers with soft segment cross-linking is mostly concentrated on small molecule chain extenders with more than three functionalities (mostly TMP) and high-functionality polyester polyols. Big limitations:

[0007] 2. Using the scheme of high-functionality small-molecule chain extender, in the actual production process, the proportion of small-molecule alcohols with different functionalities is not easy to be accurately controlled, and the continuity and stability of production are not easy to guarantee, which is likely to cause product failure. The quality fluctuates, and even the problem that the product cannot be plasticized;

[0008] 3. In the scheme of using high-functionality polyester polyol, there is a problem that the polyol has a high viscosity and is not easy to mix evenly

The higher the functionality of polyester polyol, the greater the viscosity of the material, and there is a great quality hidden danger in use

And as the functionality of polyester polyol increases, its spatial network structure becomes more and more obvious, the fluidity of the melt will decrease sharply, and the processing temperature will become higher and higher, which will greatly affect the plasticizing process of polyurethane elastomers. influences

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