摘要
以大豆油为初始原料,通过配合运用热稠化和臭氧氧化/还原技术,成功制备出了生物基多元醇。系统研究了热稠化时间对多元醇性质的影响。大豆油所含亚麻酸和亚油酸具有双烯丙基结构,它们所含有的大量碳碳双键在高温下发生迁移生成共轭结构,继而发生分子内或分子间的Diels-Alder反应。随热稠化时间延长,碳碳双键的含量逐渐变少,臭氧氧化/还原后所得多元醇的羟值由220. 4 mg KOH/g降低为94. 3 mg KOH/g,从而影响所得聚氨酯薄膜的力学性能和热性能。聚氨酯薄膜样品由生物基多元醇与4,4'-二苯基甲烷二异氰酸酯(MDI)发生聚合反应制备得到。分别应用差示扫描量热仪(DSC)、热失重(TGA)、拉伸测试考察了聚氨酯薄膜的性能,并与大豆油直接臭氧氧化所得聚氨酯薄膜的性能进行了比较。研究发现,经过臭氧氧化,聚氨酯薄膜的韧性和断裂伸长率大幅度提高了。但是当热稠化时间达到3 h,所得多元醇的羟值大幅度降低,使得聚氨酯薄膜的力学性能劣化。为通过大豆油制备含有高反应活性伯羟基的生物基多元醇提供了一种简便、实用的方法,并有望应用于其他具有高含量亚麻酸或亚油酸的植物油。
Bio-based polyols could be successfully prepared from soybean oil through heat-bodying followed by ozonolysis.The effects of the heat-bodying time on the properties of the polyols had been systematically studied.The linolenic and linoleic fatty acids in soybean oil had diallyl structure,which could be transformed from carbon-carbon double bonds to conjugated structure at elevated temperature,facilitating intra or inter molecular Diels Alder Cyclization.As the increase of thickening time,the contents of carbon-carbon double bonds could decrease and the hydroxyl value number of the polyols could decrease from 220.4 mg KOH/g to 94.3 mg KOH/g,which could affect the mechanical properties and thermal properties of polyurethane films.Polyurethane films were prepared by the polyreaction of 4,4′-diphenylmethane diisocyanate(MDI)and bio-polyols,which could be investigated by differential scanning calorimetry(DSC), thermogravimetric analysis(TGA)and tensile test,and then compared with the polyurethane from ozonated unpolymerized soybean oil.The results reveal that mechanical properties,such as,elongation at break and toughness could be improved by ozone oxidition.However,when the heat-bodying time could achieve 3 hours,the hydroxyl value of polyols could decline dramatically and decrease the mechanical properties of polyurethane.This paper provides a simple and practical method to synthesize the polyols with high reactivity primary hydroxyl groups,which could apply to the usage of other vegetable oil contain linoleic or linolenic fatty acid.
作者
陈凯骏
黄裕中
申华
卞冬明
汤继俊
张竞
CHEN Kai-jun;HUANG Yu-zhong;SHEN Hua;BIAN Dong-ming;TANG Ji-jun;ZHANG Jing(College of Materials Science & Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China)
出处
《塑料工业》
CAS
CSCD
北大核心
2019年第2期37-41,156,共6页
China Plastics Industry
基金
江苏省产学研前瞻项目(BY2016073-12)
泰州市科技支撑计划(产业关键技术研发)项目(TG201811)
