原子转移自由基聚合合成甲基丙烯酸丁酯与丙烯酸全氟烷基乙酯两嵌段共聚物及其性能的研究

SYNTHESIS AND CHARACTERIZATION OF DIBLOCK COPOLYMER OF BUTYL METHACRYLATE AND PERFLUOROALKYL ACRYLATE

通过原子转移聚合合成了大分子引发剂PBMA Br及系列含氟两嵌段共聚物P(BMA b FAEM) ,并利用1 H NMR、F EA、GPC、FTIR对其结构进行了表征 .所合成的含氟嵌段共聚物膜具有低临界表面张力 .本文通过接触角的测定研究了含氟两嵌段共聚物的憎水、憎油性能与共聚物的含氟量 ,热处理温度 ,热处理时间的关系 ,结果表明含氟嵌段PFAEM具有向空气 聚合物界面富集的倾向 ,在共聚物中引入含氟嵌段可以明显提高共聚物的憎水、憎油性 .当含氟嵌段达 7 6wt%时 ,临界表面张力 (γc =18 7mN m)已与聚四氟乙烯相当 (γc=18 5mN m) 。

Two series of semifluorinated fluorocarbon diblock copolymer P(BMA\| b \|FAEM) have been synthesized by atom transfer radical polymerization (ATRP),and the ATRP of fluorinated monomer FAEM initiated by bromine\|endcapped PBMA was studied in detail.GPC data showed the block copolymer molecular weight increased linearly with fluorinated monomer conversion.And efficient block copolymer formation had been demonstrated by FTIR and H\|NMR,which is indicative of good living character.Combining the GPC and fluorine\|element analysis,the molecular weight of fluorinated copolymer was calculated more accurately,the experimental results matched the design very much.Measurements on the thin (perfluoroalkyl) ethyl acrylate\|containing acrylic polymer films showing low critical surface tensions and low dispersion force contributions to the surface energy indicated the presence of the fluorinated block at the surface.The results showed that the water and oil repellency increased with the fluorine content in the diblock copolymer.After annealing at different temperatures or different time,the water and oil repellent properties of diblock copolymer were increased to approach maximum values.These phenomena prove the propensity of polymer for fluorine enrichment at air\|polymer surface.The sample BMA 96 FAEM 3.1 ( γ c=18.7) with incorporation of 10.6wt% (perluoroalkyl) ethyl acrylate FAEM has obvious water and oil repellent property.Water and paraffin liquid contact angles for the sample BMA 96 FAEM 3.1 were larger than 100 and 75 degrees respectively,it could be estimated that surface tensions of these polymers were comparable to that of PTFE ( γ c=18.5).The block copolymer surface showed notable hydrophobic and lipophobic property.