A water-absorptive soft contact lens comprising a polymer prepared by polymerizing a monomer mixture comprising (A) a fluorine-containing styrene derivative represented by the general formula (I):
wherein R1 is hydrogen atom or methyl group, m is an integer of 1 to 3 and n is 0 or an integer of 1 to 7, and (B) N,N-dimethyl(meth)acrylamide. The water-absorptive soft contact lens has excellent oxygen permeability, high mechanical strength and excellent flexibility independent of water content.
Engineering low surface energy polymers through molecular design: synthetic routes to fluorinated polystyrene-based block copolymers
作者:Luisa Andruzzi、Emo Chiellini、Giancarlo Galli、Xuefa Li、Seok H. Kang、Christopher K. Ober
DOI:10.1039/b200891b
日期:2002.5.22
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.
我们采用两种不同的合成路线合成了在侧链中含有氟化芳香族取代基的新型窄聚分散聚苯乙烯嵌段共聚物:(i) TEMPO 介导的氟化苯乙烯单体受控自由基聚合;(ii) 阴离子形成的聚苯乙烯-嵌段-聚异戊二烯嵌段共聚物的一系列聚合物改性反应。采用前一种方法,可获得 AB 二嵌段和 ABA 三嵌段共聚物,其中 B 嵌段含有一系列 nCF2 基团(n = 4、6 或 8)的碳氟化合物链取代基。按照后一种方法,通过阴离子聚合制备了聚苯乙烯-嵌段-聚异戊二烯 AB 二嵌段共聚物,然后通过引入具有不同数量 CF2 基团(n = 6 或 8)的含氟尾端进行改性。研究了含氟嵌段共聚物的热行为和块体微观结构,并评估了化学结构对性能的影响。所有样品都显示出在体积中形成层状介相的趋势,增加侧链碳氟化合物尾部的长度可提高介相的有序度,从无序的自成体系(n = 4 或 6)到有序的假六方自成体系(n = 8)。以水为润湿介质测量了嵌段共聚物薄膜的接触角。结果发现,先进接触角的值高达 130°(后退角为 120°),而且在水中长时间浸泡也保持不变。