氟代聚丙烯酸酯改性聚氨酯复合乳液的制备及其疏水性

Synthesis and performance of cationic fluorinated polyacrylate modified polyurethane composite emulsion

为了提高聚氨酯-丙烯酸酯复合乳液的耐水性和耐溶剂性,将聚氨酯溶液作为反应介质,以丙烯酸十二氟庚酯(FA)和丙烯酸羟丙酯为单体,偶氮二异丁腈为引发剂,在溶液中进行聚丙烯酸酯自由基聚合,然后用N-甲基二乙醇胺进行亲水基扩链,通过溶液聚合相转化法制得新型阳离子氟代聚丙烯酸酯改性聚氨酯复合乳液。通过红外光谱、透射电镜、光电子能谱仪和接触角测定仪分别对复合乳液的结构、乳胶粒形态、膜表面的化学元素组成及疏水性进行了研究。结果表明,含氟链段成功接入了大分子链中,乳液形成稳定的核-壳结构,在膜材料表面形成了主要由含氟丙烯酸酯链段组成的界面,FA的引入可使复合乳液胶膜与水的接触角(PUA膜与水的接触角)由65°提高至98°。

In order to enhance the water and solvents resistance of polyurethane acrylate composite emulsion, a novel cationic fluorinated polyacrylate modified polyurethane composite emulsion was prepared via phase inversion solution polymerization with hydroxypropyl acrylate （HPA） and dodecylfluoroheptyl acrylate （DFHA） as starting monomers in the medium of polyurethane （PU） solution with azobisisobutyronitrile （AIBN） as initiator for free radical formation. Then the co -polymerized product was further reacted with N- methyldiethanolamine （NDMDEA） to extend its hydrophilic chain. The structure, particle morphology as well as chemical composition and hydrophobicity of the film surface of the targeted composite emulsion was characterized and examined by Infrared spectrum （IR）, X - ray photoelectron spectroscopy （XPS）, transmission electron microscope （TEM） and the contact angle determination instrument. Results indicated that fluorinated chain block is incorporated into the macro molecule chain of the polymer successfully. The composite emulsion has a stable core - shell structure. The interface composed of fluorinated acrylate （FA） chain blocks are formed on the film surface and the incorporation of FA blocks increase the contact angle between PUA film and water from 65°to 98°.