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The bagasse in the polyhydroxy alcohols liquefied made of plants polyol, and then the plant polyol with a diisocyanate, etc., to synthesize a polyurethane rigid foam. Meanwhile, of ester compound of liquefied product is modified to improve its reactive modified liquefied product is also used for the preparation of polyurethane rigid foams. Under atmospheric pressure, to sulfuric acid as the catalyst, bagasse, in polyethylene glycol 400 and glycerol constituting the liquefied reagent liquefaction reaction. And to explore the influence of the reaction time, the catalyst, the ratio of liquid to solid and liquefaction reagent composition of bagasse liquefaction reaction. By adding a reactive surfactant and modified to improve liquefaction efficiency, and to improve the liquefied product of the liquefied product. The results show that adding a surfactant in the liquefied solvent, it is possible to promote the liquefaction reagent to the raw material inside the penetration, is conducive to the rapid progress of the liquefaction reaction, improve liquefaction efficiency. Further, the presence of a surface active agent is also available to reduce the more expensive in an amount of polyethylene glycol 400, thus reducing the cost of liquefaction. By esterification, respectively?? Caprolactone and phthalic anhydride grafted to the liquefied product, the introduction of an ester group to the liquefied product. Liquefied product with an isocyanate (MDI), synthesized by the reaction of a rigid polyurethane foam and a rigid polyurethane foam properties were characterized. The results showed that in the polyol component in the use of a certain amount of liquefied product, will improve the mechanical strength of the foam material, but the amount of the liquefied product exceeds a certain limit will cause the material to become brittle, and mechanical strength is reduced. When the amount of the liquefied product of alternative reached 60%, the compression strength of the foam reached the highest 238.38kPa. Further, the improved thermal stability of the liquefied product the synthesis of a polyurethane foam, thermogravimetric occurs mainly between 220 to 440 ° C. The study also explores the impact of flame retardants, catalysts and blowing agents for polyurethane foam performance. The study found that the flame retardant to make flame-retardant foam, but can destroy the cell structure, so that the mechanical strength of the foam to reduce. The catalyst can improve the foaming rate, but can also affect the mechanical properties of the foam. The foaming agent may promote foaming, conducive to the growth of the foam. However, large amount of blowing agent will cause the collapse of bubble, affecting the mechanical strength of the foam. In addition, through the polyurethane foam heat aging study found that heat aging time, the foam compression strength becomes large, this may be because the polyurethane of the lignin reaction was continued in the aging process, increasing the degree of crosslinking of the material. The synthesis of polyurethane foam of the synthesis of a polyurethane foam by the use of modified liquefied product mechanical strength than the liquefied product is improved, but also more uniform cell structure. This shows that the modified reaction of the liquefied product activity increased. Wherein?? Caprolactone-modified polyurethane synthesized of the liquefied product foam highest compression strength and modulus of elasticity, respectively, of 226kPa and 2.65MPa. The thermal stability of the polyurethane foam modified liquefied product synthesis is also increased, it may be because there is the formation of an ester bond in the modified product.
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