含氟丙烯酸酯-聚氨酯共混膜的自组织梯度化结构

Self-organization Gradient Structure of Fluorinated Acrylate Polymer-polyurethane Blend Latex Film

通过细乳液聚合法,以异佛尔酮二异氰酸酯(IPDI)、聚醚二醇(PTMG)、N-甲基二乙醇胺(MDEA)、三羟甲基丙烷(TMP)及全氟烷基乙基丙烯酸酯(FA)为原料,制备不同FA用量的氟化聚氨酯(PUFPA)乳液。采用FTIR、AFM、SEM-EDS、XPS考察了FA用量对PUFPA乳胶膜自组织梯度结构的影响。结果表明:当FA质量分数为40%(PUFPA40%)时,乳胶膜膜-空气(F-A)面与膜-基材(F-P)面表面自由能差异显著,断面出现相分层,含氟组分(FPA)在F-A面开始富集,乳胶膜呈明显梯度化结构;乳胶膜经热处理(110℃,2 h)后,膜F-A面水接触角达到132.5°,疏水程度增大,膜正反面的表面自由能差异进一步增大,断面分层更明显,且从膜F-A面到膜F-P面沿厚度方向氟元素浓度逐渐降低,梯度化结构更加明显。

Fluorinated polyurethane(PUFPA)emulsions were synthesized by isophorone diisocyanate(IPDI),polyether diol(MDEA),N-methyldiethanolamine(MDEA),trimethylolpropane(TMP),and perfluoroalkyl acrylate(FA)via microemulsion polymerization method.The effect of FA amount on the self-organized gradient structure of PUFPA latex film was investigated by FTIR,AFM,SEM-EDS and XPS.The results showed that the prepared PUFPA containing 40%mass fraction of FA(PUFPA40%)latex film had large surface free energy difference between film-air(F-A)surface and film-polytetrafluoroethylene substrate(F-P)surface.At the same time,the cross section of PUFPA40%latex film appeared layered structure.The fluorinated component(FPA)enriched on F-A surface and the gradient structure of PUFPA40%latex film was obvious.After PUFPA40%latex film was treated at 110℃for 2 h,its contact angle(water)on the F-A surface could reach 132.5°,indicating that PUFPA40%latex film had higher hydrophobicity.Moreover,the surface free energy difference between the front and back of the film was further increased,and the layered structure was more obvious.From F-A surface to F-P surface,the concentration of fluorine gradually decreased along the thickness direction of PUFPA40%film after heat treating,and the gradient structure became more obvious.