Method for preparing water-expandable polyurethane elastomer

Abstract

The invention relates to a method for preparing water-expandable polyurethane elastomer, comprising the following steps: adding polyether glycol, isocyanate, plasticizer and nano-filler at a weight ratio of 70-90: 10-20: 10-25: 3-5 to a reaction kettle; heating, stirring; preparing polyurethane prepolymer having free isocyano-content after vacuum dehydration and reaction; uniformly mixing the prepolymer, chain extendor or crosslinking agent and catalyst; vulcanizing at controlled temperature or vulcanizing at room temperature and then secondarily vulcanizing at controlled temperature to prepare high-performance water-expandable polyurethane elastomer. The prepared elastomer has wide adjustable range of rigidity, high strength, and small loss of weight after expansion; the expansivity is high with many times of repeated expansion, and the expansion magnification is adjustable; with simple production technology, the prepared expandable polyurethane elastomer is widely applied to engineering fields such as bridge, subway, tunnel, water supply and drainage, mine water prevention and water leakage prevention.

Description

Technical field: [0001] The invention relates to a method for preparing a high-performance water-swellable polyurethane elastomer. The prepared expanded polyurethane elastomer is widely used in engineering fields such as bridges, subways, tunnels, water supply and drainage, mine waterproofing, and leakage prevention, and belongs to the preparation of sealing materials Technical field. Background technique: [0002] Water swellable elastomer is usually called water swellable rubber. It is a new type of functional polymer material with dual functions of elastic sealing and water swelling and water stopping. Since its inception in the 1970s, it has unique water stopping properties. It is widely favored by people and is widely used in waterproof and moisture-proof fields such as tunnel engineering, subway engineering, offshore oil production, precision instruments and municipal engineering. The usual water-swellable elastomer is made by introducing hydrophilic groups into the molecu...

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Problems solved by technology

[0003] The object of the present invention is to overcome the shortcomings of the prior art, aiming at the shortcomings and deficiencies of common water-swellable rubbers, such as large hydrostatic swelling mass loss, few repeatable expansion times, low strength, and low expansion rate in places with high salinity, and provide A method for preparing a water-swellable elastomer with high strength, insensitivity to mineral ions in water, small mass loss after swelling, and small change in expansion rate after repeated soaking. The water-swellable elastomer prepared by the method is not affected by the types of mineral ions in water and Influenced by the concentration, the expansion rate is high, the number of repeated expansions is high, and the expansion ratio is adjustable; the production and processing process is simple, the operation is flexible, and it can be vulcanized by heating or room temperature.

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