Tung oil-based polyol and preparation method thereof

Abstract

The invention discloses a tung oil-based polyol and a preparation method thereof. The preparation method comprises following steps: tung oil, an organic metal complex catalyst, and a hydroxylation reagent are mixed at a certain ratio, and are heated to 50 to 70 DEG C; under violent stirring, a hydrogen peroxide solution is added dropwise, adding speed is controlled so as to maintain the reaction temperature to be 70 to 90 DEG C, after adding of the hydrogen peroxide solution, reaction temperature is maintained for 3 to 5, and reaction is stopped; an obtained reaction system is subjected to filtering so as to separate the solid catalyst, is allowed to stand for layering so as to separate a water phase, and is subjected to reduced pressure distillation so as to obtain the tung oil-based polyol. The yield of the tung oil-based polyol is higher than 92%; product hydroxyl value ranges from 120 to 270mgKOH / g; acid value is lower than 1.0mgKOH / g; water content is lower than 0.1wt%; and the tung oil-based polyol can be used for preparing polyurethane materials.

Description

technical field [0001] The invention belongs to the field of polyurethane materials, and in particular relates to a tung oil-based polyol and a preparation method. Background technique [0002] Polyurethane materials have been widely used in industry and people's daily life due to their good mechanical properties and easy molding. The main raw materials used to produce polyurethane include isocyanates, polyols and other additives, of which polyols account for more than 50%. In the process of industrial production, polyols are mainly used in the field of polyurethane, so the factors affecting the polyurethane industry are also the main factors affecting the polyol market. Polyols can be divided into polyether polyols and polyester polyols according to their molecular structure. Among them, polyether polyols dominate the market, accounting for more than 70% of the entire polyol demand. [0003] Typically, polyols are prepared from petroleum. As a non-renewable resource, the...

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Problems solved by technology

However, tung oil is used to prepare high-quality vegetable oil polyols. Because tung oil has a high degree of unsaturation and is the only unsaturated vegetable oil with conjugated double bonds in nature, the iodine value reaches more than 170, and more than 85% of the unsaturated bonds are Carbon-carbon conjugated triene bonds, so the presence of conjugated double bonds in tung oil in the process of preparing polyol epoxidation makes the epoxy group highly reactive, poor in selectivity, and prone to side reactions, thereby generating macromolecular cross-links. Co-product, resulting in a sharp increase in viscosity, usually solid at room temperature, cannot be used for further synthesis of polyurethane materials

Research literature (such as Epoxidation of Natural Triglycerides with Ethylmethyldioxirane, "Journal of the American Oil Chemists' Society", 1996, 73: 461-464) has investigated the epoxidation process of unsaturated vegetable oils such as corn oil, soybean oil, sunflower oil, cottonseed oil, and tung oil. It was also found that tung oil with only conjugated double bonds undergoes a cross-linking reaction during the epoxidation process, resulting in a sharp increase in viscosity

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