苯乙烯-异戊二烯（或丁二烯）嵌段共聚物表面最外层结构的形成及其影响因素

项目名称： 苯乙烯-异戊二烯（或丁二烯）嵌段共聚物表面最外层结构的形成及其影响因素

项目编号： No.20874089

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 王新平

作者单位： 浙江理工大学

项目金额： 30万元

中文摘要： 研究了苯乙烯(S)-异戊二烯(I)（或丁二烯B）嵌段共聚物链结构、聚异戊二烯或聚丁二烯段化学结构、加工方式、加工条件等对表面最外层结构形成过程的影响。发现苯乙烯-异戊二烯-苯乙烯（SIS）三嵌段共聚物膜表面接触角的“tick-Slip”#34892;为由膜的软硬度决定。发现二嵌段共聚物SB 比三嵌段共聚物SBS有利于PB组分在表面富集。发现SBS与SB在溶液成膜过程中，所得膜的表面结构主要由动力学因素所决定。发现适当的成膜溶剂（如环己酮）可以制备表面环境响应性SIS膜。发现SBS甲苯溶液浇铸膜主要以PS柱垂直于表面的结构存在；而SIS膜是以PS柱平躺的指纹状结构。发现PI以1,4加成为主的SIS二甲苯溶液浇铸膜表面由1,4-PI组成，而PI以3,4加成为主的SIS膜表面为PS和3,4-PI共存，即使3,4-PI的表面能远小于PS链段。发现SBS膜的粘结力与近表层PS含量成线性关系，对最表层组分的变化不敏感。发现加入的增粘剂主要富集到SBS膜表面，增加了黏接力；加入的增塑剂没有这一趋势，降低了的硬度，对材料的黏接力影响很小。同时动力学因素在表面结构的形成时常常起着很重要的作用。

中文关键词： 嵌段共聚物； 表面结构； 和频光谱；成膜过程；苯乙烯/丁二烯嵌段共聚物

英文摘要： The effects of chain architecture, chemical structures of polyisoprene or polybutadiene and film formation methods on the formation of surface structure at outermost layer of the resulting films were incestigated. It was found that the stick-slip behavior during advancing contact angle measurement was attributed mainly to surface viscoelasticity for poly(styrene-b- isoprene-b-styrene) (SIS)triblock copolymers. The surface structure formation of the styrene(S)/butadiene (B) block copolymer films during the solution-to-film process was found to be controlled mainly by dynamic factors, such as the mobility of the PB block in solution. It has found that the chemical structure of PI block would affect the surface structure of SIS films. The surface of SIS film containing 1,4-PI was dominated by 1,4-PI segment which has lower surface energy. While both PS and PI coexist on the outmost surface of SIS film, when 3,4-PI was selected as a mid-block, even though the surface energy of 3,4-PI is lower than the PS segment.The results show that the surface of SIS film cast with cyclohexanone solution was composed of PS and PI. Such surface structure show reversible switching properties if it is alternately exposed to PI-selective solvent cyclohexane and PS-selective solvent butanone vapor. As for the film prepared with toluene and cyclohexane solution, PI segment tends to segregate and covers the surface, and the outmost surface was irreversible after exposure to different selective solvent vapor treatment. Surface morphology and chemical composition of polystyrene-block -polydiene-block-polystyrene triblock copolymer films casted with toluene solution depend on the chemical structure of mid-block (PB or PI). When the mid-block was PI segment, SIS film easily formed a structure of PS cyclinders parallel to the surface. The outmost surface of the film was occupied by pure PI which has lower surface energy. While PB as mid-block, the PS cyclinders near the surface was perpendicular to the surface, PB coexist with PS at the outmost surface of SBS cast film. It is found that the adhesion force at the nanoscale of SBS films was mostly affected by the content of PS near the surface, but was insensitive to the composition at the outmost surface. The results show that the tackifier was segregated to SBS films surface resulting in increasing adhesion and tack, whill the plasticizer was not found on the surface resulting in decreasing stiffness of SBS film when the chemicals mentioned above was added to SBS respectively. At the same time, the results show that the kinetic effect play an important role in the formation of surface in styrene/butadiene (or isoprene) block copolymer, in addition to thermodynamic effect which was usually considered as critical factor.

英文关键词： Block copolymer; surface structure; SFG; Flim formation;styrene/butadiene block copolymer