Poly(ethylene-block-vinylalcohol) film with amphiphilic surface at high temperature
Poly(ethylene-block-vinylalcohol) film with amphiphilic surface at high temperature
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高温下具有两亲表面的聚(乙烯-嵌段-乙烯醇)薄膜
DOI：
10.1002/pat.174
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发表时间：
2002
影响因子：
3.4
通讯作者：
Nobuhiko Hikasa
中科院分区：
文献类型：
--
作者：
K. Shimamura;Y. Munesawa;T. Uchida;Nobuhiko Hikasa
以聚乙烯单晶为原料，制备了由疏水嵌段和亲水嵌段组成的聚乙烯/聚乙烯醇(PE/PVA)共混物。聚乙烯单晶与发烟硝酸反应生成末端带有COOH、NO2等官能团的亚甲基长链(链长与聚乙烯单晶的片层厚度基本相同)。功能化的亚甲基链与4-氨基苯乙烯反应生成相应的酰胺，即末端带有乙烯基团的亚甲基链(大分子)。将大分子单体与乙酸乙烯酯进行嵌段共聚，然后进行皂化反应，得到PE/PVA嵌段共聚物。
嵌段共聚物被模制成片状，随后在与亲水或疏水介质接触的情况下进行热处理。根据介质的不同，板材表面在高温下可逆地从亲水变为疏水，反之亦然。表面性质通过淬火固定，因为两个块都能结晶。因此，这种材料的表面可以在高温下为各种用途量身定做，然后在室温下稳定使用。版权所有©2002 John Wiley&Sons，Ltd.
Poly(ethylene-block-vinylalcohol) (PE/PVA), which consisted of both hydrophobic and hydrophilic blocks, was prepared by using polyethylene single crystals as starting material. Polyethylene single crystals were reacted with fuming nitric acid resulting in long methylene chains with functional groups such as COOH and NO2 at the ends (the chain lengths were almost the same as the lamellar thickness of polyethylene single crystal). The functionalized methylene chains were allowed to react with 4-aminostyrene to give corresponding amides, i.e. methylene chains with vinyl groups at the ends (macromer). The macromers were extended by block-copolymerization with vinyl acetate, then saponified resulting in PE/PVA block copolymer.
The block copolymer was molded into sheets which were subsequently heat-treated in contact with hydrophilic or hydrophobic media. Depending on the media, the sheet surface changed at high temperature reversibly from hydrophilic to hydrophobic and vice versa. The surface property was fixed by quenching because both blocks were able to crystallize. Thus the surface of this material can be tailored for various purposes at high temperature, and then used in stable condition at room temperature. Copyright © 2002 John Wiley & Sons, Ltd.