Preparation method of modified thermoplastic polyurethane elastomer foam material

Abstract

The invention discloses a preparation method of a modified thermoplastic polyurethane elastomer foam material. The preparation method comprises the following steps: 1, stirring and mixing 100 parts by weight of a thermoplastic polyurethane elastomeric material, 0.5-10 parts by weight of a modified graphene material and 0.05-3 parts by weight of a lubricant to obtain a mixture; 2, adding pellets obtained in step 1 and water into a reaction kettle, and starting stirring; 3, introducing carbon dioxide and / or nitrogen into the reaction kettle, and controlling the pressure and the temperature in the reaction kettle to make the carbon dioxide or / and nitrogen in the reaction kettle in a supercritical state; 4, heating the reaction kettle to make the supercritical carbon dioxide or / and nitrogen dissolved in the graphene doped thermoplastic polyurethane pellets at the obtained temperature; 5, continuously adding a foaming agent and a crosslinking agent to the reaction kettle, connecting the reaction kettle with a pressure tank, and allowing the above obtained material in the reaction kettle to enter the pressure tank under the action of pressure; and 6, foaming the material in the pressure tank for 30-90 min, and carrying out pressure reducing and cooling to 70 DEG C or below in order to obtain the modified thermoplastic polyurethane elastomer foam material.

Description

technical field [0001] The invention relates to the field of thermoplastic polyurethane elastomers and foaming materials, in particular to a preparation method of modified thermoplastic polyurethane elastomer foaming materials. Background technique [0002] Thermoplastic polyurethane elastic material, or TPU, is a new type of organic polymer synthetic material, and it is the most ideal material to replace PVC and PU. It is called a new type of polymer material internationally. Polyurethane thermoplastic elastomer not only has excellent physical and mechanical properties (high modulus, high strength, high elongation, high elasticity, good toughness) and good processing characteristics, but also has low temperature softness, wear resistance, oil resistance, air permeability , transparency, and can be recycled for secondary processing. Therefore, TPU is widely used in automobiles, wire and cable, adhesive, medical, shoe materials, toys, clothing, pipes, rollers, aviation and ...

AI Technical Summary

Problems solved by technology

Among them, the batch molding technology is to put the preformed semi-finished product into the autoclave, and inject the inert gas or supercritical fluid under a certain pressure and temperature, and then quickly raise the temperature or lower the pressure after reaching the equilibrium of diffusion and dissolution to make the saturated gas nucleate and expand, shape and form. The obtained microcellular foam material; this method is by physical foaming, because there is no stable bond formed between TPU and TPU, the foaming effect is not good

The injection molding process generally mixes the injected foaming agent with the polymer melt uniformly through the mixing element of the screw head device, and then releases the gas after the foaming agent is heated and decomposed, and forms pores in the polymer composition; this method Through chemical foaming, it is easy to cause uneven foaming due to dispersion problems and is difficult to control

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