Preparation method of silicone rubber polyurethane thermoplastic elastomer

Abstract

The invention relates to a silicone rubber polyurethane thermoplastic elastomer and a preparation method thereof. The silicone rubber polyurethane thermoplastic elastomer comprises the following components in parts by weight: 50-80 parts of polyol, 10-30 parts of dual-component liquid organic silicone rubber, 15-40 parts of diisocyanate, 3-10 parts of a chain extender and 0.1-2 parts of an auxiliary agent. The silicone rubber polyurethane thermoplastic elastomer product is synthesized by a one-step reactive extrusion process. The obtained thermoplastic elastomer product has excellent properties of both organosilicone and polyurethane materials, has the advantages of fine micro-morphology structure, smooth touch sense, and excellent mechanical properties and elasticity, and can be widely applied in medical devices, intelligent wearing equipment and other fields.

Description

technical field [0001] The invention relates to a thermoplastic elastomer, in particular to a preparation method of a silicone rubber polyurethane thermoplastic elastomer, which belongs to the field of polymer material processing. Background technique [0002] Silicone rubber refers to the rubber whose main chain is composed of silicon and oxygen atoms alternately, and there are usually two organic groups attached to the silicon atoms. A notable feature of silicone rubber is its excellent temperature resistance. It can maintain excellent stability under high and low temperature conditions. In the high temperature environment above 200 ℃, silicone rubber can still maintain a certain degree of flexibility, resilience and surface hardness, and there is no obvious change in mechanical properties. The weather resistance and aging resistance of silicone rubber are also very outstanding, but the mechanical strength of silicone rubber is poor, and it only has moderate oil resistanc...

AI Technical Summary

Problems solved by technology

However, the dynamic vulcanization process cannot solve the problem of poor compatibility between non-polar silicone rubber and polar polyurethane materials, and due to the huge difference in viscosity between silicone rubber and thermoplastic polyurethane elastomer materials, rubber is not easy to shear, Broken to form uniform and tiny dispersed phase particles, eventually resulting in the microscopic morphology of silicone rubber polyurethane thermoplastic vulcanizate is not fine enough, the mechanical properties and elasticity are also poor, and the tensile strength is generally lower than 10Mpa

In addition, in order to fully vulcanize the silicone rubber, the dynamic vulcanization process generally requires a long mixing time in the internal mixer or extruder, generally not less than 6 minutes, not only requires high process stability control, but also long-term thermal shear treatment It will have adverse effects on the properties of thermoplastic polyurethane elastomer substrates. At the same time, precious metal catalysts such as platinum need to be used to initiate crosslinking in the dynamic vulcanization process, which is costly and prone to platinum black impurities

To sum up, the process control of the thermoplastic silicone rubber polyurethane elastomer prepared by the current dynamic vulcanization process is relatively complicated, and the prepared product is to a certain extent only the silicone material as one of the components of the thermoplastic material, showing poor uniformity so that in At high silane content, there are regions that are basically only siloxane and basically only thermoplastic resin, the composition is fragile, and the excellent properties of silicone materials cannot be fully utilized in use, and the tensile strength, elongation at break, tear Properties such as cracking strength are still at a low level

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