界面活性劑種類及添加量對多元醇液化柳杉木材製造聚胺基甲酸酯(PU)發泡體之影響

Abstract

Cryptomeria japonnica (Japanese cedar) was liquefied in polyethylene glycol/glycerol co-solvent with H2SO4 and HCl as a catalyst. The liquefied Japanese cedar was blended with PMDI (poly-4, 4'-diphenylmethane diisocyanate), and adding water as a blowing agent, organosiloxane as a surfactant and dibutyl tin dilaurate as a catalyst to prepare the polyurethane (PU) foams. The effects of the kind and dosage of surfactant and the molar ratio of NCO/(COOH+OH) for PMDI to liquefied Japanese cedar on the properties of PU foams were investigated. The results showed that surfactant should be added to improve the compatibility and reactivity as liquefied Japanese cedar was used in the manufacturing of PU foams. For liquefied Japanese cedar that liquefied with H2SO4 as catalyst, using DC-193 as the surfactant had the better foaming effect. The PU foams had higher compression stress and higher weight retention after dissolve testing. But using DC-5188 and DC-198 as the surfactant would be better for liquefied Japanese cedar that with HCl as catalyst. The effect of the dosage of surfactant was depended on molar ratio of NCO/(COOH+OH) used for PU resins. For the PU foams made with the molar ratio of NCO/(COOH+OH) of 1.2, increasing the dosage of surfactant would decrease their compression stress. But for the molar ratio of 1.5 and 1.8, appropriately increasing the dosage of surfactant could improve the affinity for each component in the PU resins. The compression stress would be raise as the dosage of surfactant was increased.