Engineering low surface energy polymers through molecular design: synthetic routes to fluorinated polystyrene-based block copolymers
Engineering low surface energy polymers through molecular design: synthetic routes to fluorinated polystyrene-based block copolymers
复制标题
DOI：
10.1039/b200891b
复制
发表时间：
2002-05
影响因子：
--
通讯作者：
L. Andruzzi;E. Chiellini;G. Galli;Xuefa Li;K. Ho;C. Ober
中科院分区：
文献类型：
--
作者：
L. Andruzzi;E. Chiellini;G. Galli;Xuefa Li;K. Ho;C. Ober
通过两种不同的合成路线合成了侧链含氟芳香取代基的新型窄多分散聚苯乙烯嵌段共聚物：(I)TEMPO介导的含氟苯乙烯单体的可控自由基聚合；(Ii)对阴离子形成的聚苯乙烯-嵌段-聚异戊二烯嵌段共聚物进行一系列的聚合物改性反应。采用前一种路线，将一段含氟碳链取代基的聚苯乙烯嵌段(n=4、6或8)作为B嵌段，合成了AB二嵌段和ABA三嵌段共聚物。采用后一种方法，通过阴离子聚合制备了聚苯乙烯-嵌段-聚异戊二烯AB两嵌段共聚物，然后通过引入不同CF2基数(n=6或8)的氟化尾巴进行改性。研究了含氟嵌段共聚物的热行为和本体微观结构，评价了化学结构对其性能的影响。所有样品都有在块体中形成层状中间相的趋势，随着侧链氟碳尾长度的增加，中间相从无序近晶(n=4或6)到有序伪六方近晶(n=8)的有序度增加。以水为润湿介质，测定了嵌段共聚物膜的接触角。超前接触角高达130°(120°后退角)，在水中浸泡时间较长时保持不变。
New narrow polydisperse polystyrene-based block copolymers comprising fluorinated aromatic substituents in the side chains were synthesized following two different synthetic routes: (i) TEMPO-mediated controlled radical polymerization of fluorinated styrene monomers; (ii) A sequence of polymer modification reactions on anionically formed polystyrene-block-polyisoprene block copolymers. Using the former route, AB diblock and ABA triblock copolymers were obtained in which a block of polystyrene bearing a fluorocarbon chain substituent with a range of nCF2 groups (n = 4, 6, or 8) was incorporated as B block. Following the latter route, polystyrene-block-polyisoprene AB diblock copolymers were prepared by anionic polymerization and then modification by introduction of fluorinated tails with different numbers of CF2 groups (n = 6 or 8). The thermal behavior as well as the bulk microstructure of the fluorinated block copolymers were investigated and the effect of the chemical structure on the properties was evaluated. All the samples showed a tendency to form layered mesophases in the bulk, and increasing the length of the fluorocarbon tail of the side chain enhanced the degree of order of the mesophase from a disordered smectic (n = 4 or 6) to ordered pseudohexagonal smectic (n = 8). Contact angles of block copolymer films were measured using water as the wetting medium. Values of advanced contact angles up to 130° (120° receded angles) were found which were quite constant over prolonged immersion times in water.