A kind of method for recycling waste polyurethane elastomer to prepare polyurethane insulation material

Abstract

The invention relates to a method of preparing a polyurethane thermal insulation material by recovering a waste polyurethane elastomer. The method comprises the following steps: (1) mixing the waste polyurethane elastomer, an alcoholysis agent and an alcoholysis additive, stirring for 1-10h at the temperature to be 100-200 DEG C, cooling to room temperature, and degrading to obtain a recovery product; and (2) uniformly stirring the recovery product after degrading, a chain extender, a foaming agent, a foam stabilizer, a catalyst and water to be used as a white material, stirring the white material and a black material, foaming, and cooling to obtain the polyurethane thermal insulation material. The method is simple in processing process and easy to operate and can be put into production. According to the method disclosed by the invention, the thermal insulation performance of the product is excellent, the thermal conductivity reaches above 0.02W / m.K, and the apparent density, the water absorption, the compressive strength and the like of the polyurethane thermal insulation material all achieve the national standard.

Description

Technical field [0001] The invention belongs to the field of polyurethane elastomer waste recycling, and particularly relates to a method for preparing polyurethane thermal insulation materials by recycling waste polyurethane. Background technique [0002] Polyurethane elastomer is a polymer material with superior performance. It has light weight, wide range of hardness, high strength, large adjustable range of performance, wear resistance, oil resistance, excellent ozone resistance, shock absorption, radiation resistance and breathability. Good performance, diverse processing methods and wide applicability. It is widely used in military industry, aerospace, acoustics, biology and other fields. Among them, tires with high wear resistance; sleepers with light weight, good shock absorption, and aging resistance; not only extend the service life, but also reduce the noise of the operating environment, and the sieve plate used in coal plants with obvious energy saving and consumptio...

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Problems solved by technology

[0004] In the patent document (CN201410000590.8), it is proposed to use waste polyurethane foam to prepare high-quality activated carbon, which reduces the impact of waste polyurethane foam on the environment; Liquid polyurethane (PU) resin, so that it has higher peel strength and solvent resistance. However, the sources in the above patents are mainly waste polyurethane foam and polyurethane shoe soles, and do not involve the recycling of waste polyurethane elastomers.

In the patent (201310091432.3), it is proposed to use a mixture of ethylene glycol and ethanolamine as an alcoholysis agent, and use lithium acetate, sodium acetate or potassium acetate as a catalyst to cast a polyurethane elastomer at 145-195°C, and the reaction time is 5.5-6.5 h degradation, cooling the reactant until the upper layer becomes solid and the lower layer is still liquid, reacts the recovered upper layer solid with isocyanate to prepare thermoplastic polyurethane pellets; distills and purifies the recovered lower layer product to prepare rigid polyurethane foam However, the utilization rate of the degraded product will decrease due to the stratification of the recyclate after degradation. Moreover, the polyurethane foam must be prepared after distillation and purification in the process, which is relatively complicated.

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