疏水性含氟聚氨酯的合成及其耐气蚀磨损性能的研究  

Cavitation Erosion Resistant Hydrophobic Fluorinated Polyurethane

作　　者：张瑞珠[1] 卢伟[1] 严大考[1] 刘晓东[1] 

机构地区：[1]华北水利水电大学机械学院,郑州450045

出　　处：《高分子学报》2015年第7期808-818,共11页Acta Polymerica Sinica

基　　金：水利部科技推广计划(项目号TG1420);河南省重点科技攻关项目(项目号122102210241)资助

摘　　要：采用全氟烷基乙醇（TEOH-10）对二苯基甲烷二异氰酸酯（MDI）进行修饰的方法引入氟元素,同时通过控制反应过程中MDI加入用量和时机,制备了无亲水性—CH2OH基团、且具备含氟链段的聚氨酯（FPU）.耐水性实验表明,由于低表面能的氟碳链（—CF2CF3）向材料表面迁移,并在表面形成＂荷叶疏水效应＂的有机氟膜,FPU表现出很强的疏水性,当TEOH-10的摩尔用量为MDI理论用量的0.3-0.5之间时,FPU的吸水率仅在0.0146%-0.0182%之间,并在吸水浸泡实验浸泡3200 h后保持10.31-10.79 MPa的高粘结力;抗冲蚀磨损实验结果表明,FPU涂层具有优异的抗冲磨和气蚀性能,随着氟含量的增加,聚氨酯硬段组分中含氟F-MDI分子间的内聚能增加,提高了硬段微区的弹性模量和抗张强度,并通过氢键结构协同软段分子链的运动,缓冲了高速磨损颗粒和气泡溃灭时对涂层产生巨大反复的冲击力,使FPU的空蚀量由2.3756×10-3kg降低到0.9334×10-3-1.2454×10-3kg之间,涂层的耐气蚀磨损性能得到明显提高.综合考量水下过流部件防护涂层实际应用的性能要求,当TEOH-10/MDI的摩尔比约为0.5,即氟元素的质量百分数约为9.39%时,FPU具备较好的耐水性能、粘结力和耐气蚀磨损性能,可望用作于一些气蚀现象严重的水下过流部件的防护涂层.Hydrophobic fluorinated polyurethanes（ FPU） with no hydrophilic —CH2OH groups were prepared,by using the method of introducing fluorine with perfluoroalkyl ethanol（ TEOH-10） for modification of diphenylmethane diisocyanate（ MDI） and controlling the MDI adding dosage and time. Water resistance experiments indicated that the FPU showed strong hydrophobic properties,owing to the low surface energy of fluorocarbon chains（ —CF2CF3） migrated to the surface of the material and formed the organic fluorine membrane which was equivalent to the ＂lotus leaf hydrophobic effect＂. Especially when the molar ratio of TEOH-10 was 0. 3 - 0. 5 to the theoretical quantity of MDI,the water absorption of FPU was only between0. 0182% and 0. 0146%,and the high bonding force of FPU was maintained at 10. 31 - 10. 79 MPa after soaking in water for 3200 h. The erosion wear experiments showed that the anti-erosion performance of FPU was continuously improved with the increase of fluoride content,however,the cohesive force of FPU was continuously reduced because of the increasing fluoride content. When the mole ratio of TEOH-10 / MDI was0. 5,the cavitation erosion amount of FPU reduced from 2. 3756 × 10- 3kg to 0. 9334 × 10- 3kg,and the cohesive force of FPU stayed above 10 MPa. These hydrophobic fluorinated polyurethanes are promising to be used as a protective coating of under-water flow parts.

关 键 词：含氟聚氨酯 有机氟膜 过流部件 疏水性 耐气蚀磨损性能 

分 类 号：TQ630.1[化学工程—精细化工]