利用麦秆制聚氨酯多元醇研究

以小麦秸秆为原料,在浓硫酸催化作用下以聚乙二醇(PEG400)为液化试剂进行液化,讨论了麦秆纤维粒径、催化剂用量、乙二醇(EG)加入量、反应温度和时间等因素对液化残渣率的影响.结果表明:当纤维为"＞12目",EG用量为20%,浓硫酸用量为4%,在160℃下反应60min时,所得残渣率最小,为0.8%.羟值、酸值的测试结果和红外分析结果表明,液化过程中羟值逐渐减小,而酸值则呈现先增大后减小的趋势,说明反应后期有酯缩合反应发生.将液化产物与二苯基甲烷二异氰酸酯(MDI)反应可制成泡沫材料,红外光谱证实生成物具有聚氨酯的典型特征.得到的泡沫材料密度为38kg/m3,抗压强度为118kPa,性能优良.

Research on Liquefaction of Wheat Straw for Polyurethane Polyol

Using sulfuric acid as catalyst,wheat straw can be liquefied into polyol by polyethylene glycol (PEG400).In such a process of straw liquefaction,the particle size of straw fiber,the amount of ethylene glycol (EG) and catalyst used,the reaction temperature and time were investigated.The results showed that only 0.8% of residues remained at the optimum conditions: the size of fiber more than 12 mesh,20% of EG,4% of concentrated sulfuric acid,and 60 minutes of reaction time at the temperature of 160℃.At the same time,hydroxyl value test,acid value test and infrared spectroscopy were used to monitor the conversion process.As opposed to gradually decreasing hydroxyl value,the acid value firstly increased and then decreased,which meant the ester condensation reaction occurred at the final stage of conversion process.This paper also investigated the possibility to produce polyurethane foam using methylene diphenyl diisocyanate(MDI) and polyol derived from wheat straw.By testing,the foam product had a density of 38Kg/m~3 and a compressive strength of 118KPa,and further confirmed by infrared spectroscopy,it has a characteristic structure of polyurethane.