Surface properties and metathesis synthesis of block copolymers including perfluoroalkyl-ended polyethylenes
Surface properties and metathesis synthesis of block copolymers including perfluoroalkyl-ended polyethylenes
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全氟烷基封端聚乙烯嵌段共聚物的表面性质和复分解合成
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
L. Firment
中科院分区：
文献类型：
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作者：
S. Mclain;B. Sauer;L. Firment
在部分氟化无环烯烃（链转移剂）存在下，通过环十二烯开环复分解聚合，然后在主链上还原双键，制备了端基为氟烷基的线性聚乙烯。得到了一端或两端以F(CF2)10或F(CF2)4基团为末端的样品的熔体表面张力（γ）。具有两个全氟末端的聚乙烯，即PE(C10F21)2，在降低γ方面最有效。在体积中只有10%原子F时，获得的γ值甚至低于纯聚四氟乙烯的值。通过前后接触角测量和角度相关的x射线光电子能谱（XPS）对选定的端氟烷基聚合物薄膜表面进行了表征。十六烷的推进接触角高达70°，表明全氟的表面浓度很高。
Linear polyethylene with fluoroalkyl end groups has been prepared by ring-opening metathesis polymerization of cyclododecene in the presence of partially fluorinated acyclic olefins (chain transfer agents), followed by reduction of the double bonds in the backbone. Melt surface tensions (γ) were obtained for samples with one or both ends terminated by F(CF2)10 or F(CF2)4 groups at different molecular weights (MWs) of the hydrocarbon segments down to oligomeric sizes. The polyethylenes with two perfluorinated ends, i.e., PE(C10F21)2, were the most effective at lowering γ. At only 10% atomic F in the bulk, values of γ were obtained which were even lower than those for pure poly(tetrafluoroethylene). The surfaces of films of selected fluoroalkyl-terminated polymers were also characterized by advancing and receding contact angle measurements and angle dependent X-ray photoelectron spectroscopy (XPS). Advancing contact angles in hexadecane were as high as 70°, indicating a high surface concentration of perfluo...