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Polyurethane is widely used in chemiistry, light industry, textile construction, household appliances, transportation, aerospace and other fields, and in the automotive, building materials are taking place of other materials trends. Polyurethane foam is one of the major kinds of synthetic materials, its main features is porous, so the proportion is small, specific strength is high. Except isocyanate the raw materials of polyurethane rigid foam, there are polyether combinations and foaming agent. Polymethylene polyphenylene isocyanate discussed in this article is one of the main varieties of isocyanate series.With the wide application of polyurethane, isocyanate quality abtains more and more attention. Applications of polyurethane products differ, as different indicators of the isocyanate requirements are also different. The current national standard GB/T 13658-92 only provides for routine testing project(appearance, isocyanato content, viscosity, acidity, hydrolyzable chlorine content, density). With the detection methods and technology continues to evolve, more testing has room for improvement. As more problems were founded in the application process, the new test items are rising to meet.This dissertation includes the following:1. Polyurethane knowledge and isocyanate basic chemical reactions.2. Discussion of the isocyanate routine testing and optimization.3. Proposing new testing of isocyanate.In order to provide information to the related follow-up, in this study, optimization of detection will be founded under the existing test methods, and the new test items are rising to meet.
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