溶剂在丁腈基聚氨酯中的溶解和扩散

用石英弹簧法和示差扫描量热法 (DSC)、红外分光光度计 (FTIR)研究了苯、乙醇、丙酮、醋酸乙酯和1,2 二氯乙烷五种溶剂在端羟基聚丁二烯 丙烯腈共聚物为软段的聚氨酯中的溶解和扩散行为 .结果表明所有溶剂在丁腈聚氨酯中的扩散均为非费克扩散 ,且随着溶剂蒸汽压增大偏离费克扩散的程度增大 .相同相对蒸汽压下 1,2 二氯乙烷和醋酸乙酯偏离费克 (Fickian)扩散的程度较大 ,而乙醇、丙酮和苯则较小 ,这主要与它们和丁腈软段溶解度参数的极性分量和氢键分量有关 .1,2 二氯乙烷和苯在HTBN PU中的溶解度较高 ,而乙醇 ,醋酸乙酯和丙酮较低 ,主要与它们和丁腈软段溶解度参数的色散分量有关 .所有溶剂均表现出近似Flory Huggins型等温吸收曲线 .红外表明吸收溶剂后 ,氨基甲酸酯基团的氢键化程度有不同程度的下降 ,和溶剂与之形成氢键的能力大小有关 .力学性能表明非极性溶剂苯对材料的力学性能影响较小 ,而乙醇 ,醋酸乙酯和丙酮由于可与氨酯基团形成氢键 ,对原HTBN PU中氨酯键氢键的破坏大 ,力学性能下降大

SORPTION AND DIFFUSION OF ORGANIC SOLVENTS IN POLY(BUTADIENE/ACRYLONITRILE) BASED POYLURETHANE

The interactions of benzene,1,2\|dichloroethane,acetone,ethanol and ethyl acetat e with hydroxyl terminated poly(butadiene/acrylonitrile) based polyurethane(HTBN PU) and their transports in HTBN\|PU were studied by quartz spring method,DSC and FTIR measurements.The non\|fickian behavior was found for diffusion of all f ive solvents in HTBN\|PU.Higher solvent vapor pressure led to more obvious non\| fickian diffusion.In addition,higher degree of non\|fickian diffusion was found for diffusion of 1,2\|dichloroethane and ethyl acetate in HTBN\|PU,which could b e mainly attributed to their polar terms and hydrogen\|bonding terms of solubili ty parameters being closer to those of the soft matrix.The benzene and 1,2\|dich loroethane had higher solubilities in HTBN\|PU than the other three solvents,whi ch could be mainly related to their dispersive terms of solubility parameters be ing closer to that of the soft matrix.The Flory\|Huggins type sorption was found for all the five solvents in HTBN\|PU.FTIR results showed that the degree of hy drogen bonding between the urethane groups decreased after slovent uptaking.The strength of HTBN\|PU after solvent uptaking was mainly determined by the interac tion of solvent molecules with the urethane groups.Acetone,ethanol and ethyl ace tate could form hydrogen bonds with the urethane groups and therefore results in serious structure destruction and lower strength of HTBN\|PU,while the non\|pol ar benzene only slightly influenced its strength.