A kind of tung oil polyol and preparation method thereof

Abstract

The invention discloses tung oil polyol and a preparation method thereof. The preparation method comprises the following steps: mixing tung oil, carboxylic acid, an inorganic acid catalyst, a hydroxylation reagent, and deionized water according to a certain ratio, heating the mixture to a temperature of 35 to 45 DEG C; dropwise adding a hydrogen peroxide solution under violent stirring, controlling the addition speed to maintain the temperature in a range of 40 to 65 DEG C, after addition, maintaining the reaction temperature for 3 to 5 hours, stopping the reactions; allowing the reaction system to stand still to carry out layering, separating water phase from the reaction system, neutralizing the oil phase, washing the oil phase by water, and subjecting the oil phase to reduced pressure distillation to obtain tung oil polyol. The yield of the prepared tung oil polyol is more than 92%, the hydroxyl value of the product is 120 to 270 mgKOH / g, the acid value is less than 1.0 mgKOH / g, the water content is less than 0.1 wt%, and the tung oil polyol can be used to prepare a polyurethane material.

Description

technical field [0001] The invention belongs to the field of polyurethane materials, and in particular relates to a tung oil polyol and a preparation method thereof. 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, t...

AI Technical Summary

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 (e.g. Epoxidation of Natural Triglycerides with Ethylmethyldioxirane, Journal of the American Oil Chemists' Society, 1996, 73:461-464) examines different vegetable oils such as corn oil, soybean oil, sunflower oil, cottonseed oil, tung oil, etc. During the epoxidation process of unsaturated vegetable oils, 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