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结构取决于其化学结构以及结晶条件，对于含有极性基团的结晶聚合物，例如聚酯和尼龙，范德华相互作用、偶极-偶极相互作用、静电相互作用和结晶条件。聚合物链之间产生氢键，这些链间相互作用强烈影响链构象、晶体结构、层状表面上的链折叠结构和层状堆积结构。认为这些极性基团作为链中的结构缺陷而不是在晶体中，而是停留在链折叠表面。然而，极性基团在高阶结构中的空间分布细节尚未通过实验揭示。脂肪族聚酯的分子聚集结构和化学结构之间的关系提供了有关新型可生物降解聚合物的分子设计控制其结构和物理性质的重要信息。在这项研究中，线性薄膜中的分子聚集结构通过原子力显微镜 (AFM)、偏光光学显微镜 (POM)、衰减全反射 (ATR) FTIR 光谱和静态接触角测量研究了含有长亚甲基和短氟亚甲基序列的脂肪族聚酯。线性脂肪族聚酯 [O(CH2)iOCO (CF2)jCO]n (i=12, 22, j=2,8,10 :用作样品的聚酯的重均分子量Mw为约15,000，通过熔融缩聚来合成。通过溶剂浇铸方法，然后从熔体中等温结晶，薄膜的厚度约为。 1.5微米。对于所有聚酯，在其POM图像中还观察到消光环，这表明基于表面形态，链取向从球晶中心周期性变化。通过AFM观察，表明所有聚酯都形成了结晶片层。根据ATR-FTIR光谱测量，揭示了亚甲基序列。随着亚甲基数量的增加，聚酯的构象变得有序，相反，随着氟亚甲基数量的增加，亚甲基序列变得无序，CO基团周围的链间相互作用随着CO基团比例的增加而变弱。从静态接触角数据估计的薄膜的表面自由能表明，与亚甲基序列相比，氟亚甲基序列相对集中在表面区域。

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.

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。

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。