氟碳端基聚合物合成及其表面吸附性能

Syntheses of Fluoroalkyl End-Capped Polymers and Their Adsorption Properties at Interface

综述了近十年来氟端基聚合物的合成、表征及其在表面吸附行为的研究成果。通过含有氟烷基的引发剂或终止剂在活性阴离子聚合反应或自由基聚合反应中使聚合物接上氟端基。已经成功地利用活性阴离子聚合反应合成了氟端基聚苯乙烯，通过含氟自由基引发烯类单体（如丙烯酸、乙烯硅等）可在相应聚合物链上引入氟端基，另外，聚合物的化学改性方法也可将氟基团接在聚合物链端（如氟端基聚氧乙烯）。氟端基聚合物具有极强的表面活性，当水溶液中或聚合物共混体中含有极少量的氟端基聚合物时，即会发生向表面的强烈吸附现象。水溶性的氟端基聚合物水溶液在临界胶束浓度时表面张力可达到１５ｍＮ／ｍ左右。由于氟端基在空气－水界面的特殊吸附行为。

The recent achievements in syntheses and characterizations of fluoroalkyl endcapped polymers and their adsorption properties at interface were reviewed in this article. The fluoroalkyl endgroups could be introduced into polymer chains in living or free radical polymerization by the initiators or terminators containing some fluoroalkyl. The living polymerization could make the fluoroalkyl endcapped polystyrene. Free radical method could produce the fluoroalkyl endcapped polymers of the monomers such as acrylic acid and vinylsilane etc. The chemical modification of end groups in polymers also can make such a kind of fluoroalkyl endcapped polymers, for example, perfluoroalkyl polyethylene oxide. Generally, fluoroalkyl capped polymers are high surface active. The endcapped polymers were concentrated at the interface, i.e., the segregation was happened, in the solution or melt of polyblends containing the endcapped and ordinary polymer. For watersoluble fluoroalkyl endcapped polymer, the surface tension of their aqueous solution at critical micellar concentration is as low as about 15 mN/m. In the adsorbed layer at the airwater interface, the brushes structure are formed because of the special effect of the fluoroalkyl groups at the chain.