Molecular Aggreagtion Structure and Molecular Motion of Ultrathin Polymer Films

超薄膜的分子聚集结构和分子运动

• 批准号: 11694164
• 负责人: SASAKI Sono
• 金额: $ 3.52万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11694164/
• 关键词: Linear Aliphatic Polyesters; Fruoroalkylene Sequence; Thin Films; Molecular Aggregation Structure; Higher-order Structure; Molecular Conformation; Surface Free Energy of Films; Surface Topography of Thin Films; 分子鎖コンフォメーション; 一次構造制御された脂肪族高分子; 薄膜表

Molecular aggregation structure of crystalline polymers depends on their chemical structure as well as crystallization conditions. In the case of crystalline polymers containing polar groups such as polyesters and nylons, the van der Waals interaction, the dipole-dipole interaction, the static electric interaction, and the hydrogen bonding are induced between the polymer chains. These inter-chain interactions strongly influence chain conformation, crystal structure, chain folding structure on the lamellar surface, and lamellar stacking structure. It is considered that these polar groups as structural defects in chains stay rather at the chain-folding surface than in the crystal. However, the detail of spatial distribution of the polar group in the higher-order structure has not experimentally been revealed yet. Clarification of the relationship between the molecular aggregation structure and the chemical structure of aliphatic polyesters provides significant information regarding molec … More ular design of new biodegradable polymers controlled their structural and physical properties.In this study, molecular aggregation structure in thin films of linear aliphatic polyesters containing long methylene and short fluoromethylene sequences was investigated by atomic force microscopy (AFM), polarized optical microscopy (POM), attenuated total reflection (ATR) FTIR spectroscopy, and static contact angle measurements.Linear aliphatic polyesters [O(CH2)iOCO(CF2)jCO]n (i=12, 22, j=2,8,10 : iH-jF) used as samples were synthesized by melt-polycondensation of short perfluorinated dicarboxylic acids and long α-ω alkane diols. The weight-averaged molecular weight, Mw, of the polyesters was ca. 15,000. Thin films of the polyesters were prepared by the solvent-casting method, and then were isothermally crystallized from the melt. Thickness of the films was ca. 1.5 micrometers.For all the polyesters, negative spherulites were observed in their POM images. The extinction ring was also observed for the 22H-series polyesters, which indicated that chain orientation was periodically changed from the center of a spherulite. Based on the surface morphology observed by AFM, it was suggested that crystalline lamellae were formed for all the polyesters. From ATR-FTIR spectral measurements, it was revealed that methylene sequences of the polyesters became conformationally order with increasing the number of methylene groups. The methylene sequences, on the contrary, became disorder containing the gauche bonds with increasing the number of fluoromethylene groups. The inter-chain interactions around the CO groups became weaker with increasing the ratio of the number of methylene groups to that of fluoromethylene groups. The surface free energy of the films estimated from the static contact angle data implied that the fluoromethylene sequences were relatively concentrated in the surface region compared with the methylene sequences. Less

结晶聚合物的分子聚集态结构不仅取决于其化学结构，而且还取决于结晶条件。在含有极性基团的结晶聚合物如聚酯和尼龙的情况下，在聚合物链之间诱导货车德瓦尔斯相互作用、偶极-偶极相互作用、静电相互作用和氢键。这些链间相互作用强烈地影响链构象、晶体结构、片层表面上的链折叠结构和片层堆叠结构。据认为，这些极性基团作为链中的结构缺陷停留在链折叠表面而不是在晶体中。然而，在高阶结构中的极性基团的空间分布的细节还没有被实验揭示。阐明了脂肪族聚酯的分子聚集态结构与化学结构之间的关系，为分子力学研究提供了重要的信息。 ...更多信息 本文采用原子力显微镜（AFM）、偏光显微镜（POM）、衰减全反射（ATR）、傅立叶变换红外光谱（FTIR）、透射电镜（TEM）、以短链全氟二元羧酸和长链α-ω烷二醇为原料，通过熔融缩聚反应合成了直链脂肪族聚酯[O（CH 2）iOCO（CF2）jCO]n（i=12，22，j= 2，8，10：iH-jF）。聚酯的重均分子量Mw为约1.5。15,000.通过溶剂浇铸法制备聚酯薄膜，然后从熔体中等温结晶。膜的厚度为约100 μ m。1.5对于所有聚酯，在它们的POM图像中观察到负球晶。消光环也被观察到的22 H-系列聚酯，这表明，链取向周期性地改变从球晶中心。基于AFM观察到的表面形貌，表明所有聚酯均形成了结晶层状结构。从ATR-FTIR光谱测量，它揭示了聚酯的亚甲基序列变得构象有序的亚甲基基团的数目增加。相反，随着氟代亚甲基数目的增加，亚甲基序列变得无序，含有交错键。随着亚甲基与氟亚甲基数目之比的增加，CO基团周围的链间相互作用减弱。从静态接触角数据估计的膜的表面自由能暗示，氟亚甲基序列相对集中在表面区域相比，亚甲基序列。少

项目成果

T. Fujii, A. Takahara, and T. Kajiyama: "Scanning Force Microscopic Study of Polyethylene Single Crystals Prepared by a Self-seeding Method"ACS Symposium Series 741, Microstructure and Tribology of Polymer Surfaces, Edited by D. Ratner and V. V. Tsukruk.

T. Fujii、A. Takahara 和 T. Kajiyama：“自种晶法制备的聚乙烯单晶的扫描力显微镜研究”ACS 研讨会系列 741，聚合物表面的微观结构和摩擦学，D. Ratner 和 V. V. Tsukruk 编辑

A. M. Heitz, R. L. McKieman, S. P. Gido,J. Penelle, S. L. Hsu, S. Sasaski, A. Takahara, and T. Kajiyama: "The crystallization behavior of strongly interacting chains"Macromolecules. (in press). (2002)

A. M. 海茨、R. L. 麦基曼、S. P. 吉多、J.

A.M.Heintz, R.L.McKiernan, S.P.Gido, J.Penelle, S.L.Hsu, S.Sasaski, A.Takahara, T.Kajiyama: "The crystallization behavior or strongly interacting chains"Macromolecules. (in press). (2002)

A.M.Heintz、R.L.McKiernan、S.P.Gido、J.Penelle、S.L.Hsu、S.Sasaski、A.Takahara、T.Kajiyama：“结晶行为或强相互作用链”大分子。

S.Sasaki, Y.Sakaki, A.Takahara, T.Kajiyama: "Microscoipc lamellar organization in high-density polyethylene handed spherulites studied by scanning probe microscopy"Polymer. (in press). (2002)

S.Sasaki、Y.Sakaki、A.Takahara、T.Kajiyama：“通过扫描探针显微镜研究高密度聚乙烯手性球晶中的显微镜层状组织”聚合物。

K. Kojio, A. Takahara, K. Omote, and T. Kajiyama: "Molecular Aggregation State of n-Octadecyltrichlorosilane Monolayers Prepared by the Langmuir and Chemisorption Methods"Langmuir. 16. 3932-3936 (2000)

K. Kojio、A. Takahara、K. Omote 和 T. Kajiyama：“通过 Langmuir 和化学吸附方法制备的正十八烷基三氯硅烷单层的分子聚集状态”Langmuir。