A Study on Higher-Order Structure and Molecular Motions of the ionic cluster in ionomer

离聚物中离子簇的高阶结构和分子运动研究

• 批准号: 04650808
• 负责人: TSUJITA Yoshiharu
• 金额: $ 1.28万
• 依托单位: Nagoya Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650808/
• 关键词: ionomers; ionic Cluster; Ethylene Matrix; the Crystallites Formed by Annealing; DSC; Viscoelastioity; Solid-State NMR; Spin-Probe ESR Method; 高次構造; 分子運動; 電子スピン共鳴スペクトル; 粘弾性; α分散; β分散

Two endothermic peaks observed by DSC measurement around 50 - 60 ﾟC and 90 ﾟC for as received poly(ethylene-co-methacrylic acid) and its salts were attributed to the melting of polyethylene crystallites. After annealing in the cooling process, the lower temperature peak was observed at a temperature slightly higher than the annealing temperature. The lower temperature peak corresponded to the melting of the crystallites formed by the annealing and the higher one to that by cooling. The crystallization of ionomer is hindered by the presence of ionic aggregates which play a role of crosslinking. Consequently the crystallization of ionomer aged, that is, annealed at room temperature is much more remarkable than that of the copolymer or low density polyethylene. The ^<13>C spin-lattice relaxation time of the crystalline region of ionomer was shorter than that of polyethylene. This finding is suggested that size of crystal in the ionomers were relatively small than that in polyethylene. Similar interpretations on the crystal size of the ionomers were obtained from the discussion about ^1H spin-diffusion with ^1H spin-lattice relaxation times in the laboratory and rotating frames. On the other hand, the mobility of methacrylic molety in the ionic cluster was restricted in comparison with that in ethylene-methacrylic acid copolymer. Next, to discuss the motion of amorphous region, spin-probe ESR method was carried out. The temperature at which the separation of the outmost peaks of the ESR spectrum of spin-probe in polymer matrix is 50G (T_<50G>), is a valuable tool for Tg determination. The values of T_<50G> for TEMPO-containing ionomers were estimated to be about -20 ﾟC - 20 ﾟC and -25 ﾟC at low and high neutralization, respectively. This finding show that there is the distribution of the dynamical features of amorphous region in the ionomer, and the distribution changes with the neutralization.

差示扫描量热法在50~60ﾟC和90ﾟC附近观察到两个吸热峰，表明聚乙烯微晶的熔融是聚合物及其盐的主要吸热峰。在冷却过程中退火后，在略高于退火温度的温度处观察到较低的温度峰。较低的温度峰对应于退火形成的微晶的熔化，较高的温度峰对应于冷却形成的微晶的熔化。离子聚集体的存在阻碍了离聚体的结晶，离子聚集体起到了交联剂的作用。因此，离聚体的老化，即在室温下退火的结晶比共聚物或低密度聚乙烯的结晶要显著得多。离聚体晶区的自旋-晶格驰豫时间比聚乙烯短。这一发现表明，离聚体中的晶体尺寸比聚乙烯中的要小。在实验室和旋转框架下用^1H自旋-晶格弛豫时间讨论^1H自旋扩散，得到了对离聚体晶体尺寸的类似解释。另一方面，与乙烯-甲基丙烯酸共聚物相比，甲基丙烯酸分子在离子簇中的迁移率受到限制。其次，为了讨论非晶区的运动，采用了自旋探针ESR方法。聚合物基质中自旋探针ESR谱最外峰的分离温度为50g(T_t；50g&gt；)，是一种有价值的Tg测定工具。含TEMPO离聚体在低中和高中和条件下的T&lt；50g&gt；值分别约为-20ﾟC-20ﾟC和-25ﾟC。这一发现表明，离聚体中存在非晶区的动力学特征分布，并且这种分布随着中和度的变化而变化。

项目成果

Y.TSUJITA: "Membrane Science and Technology" Marcel Dekker, 56 (1992)

Y.TSUJITA：“膜科学与技术”Marcel Dekker，56 (1992)

吉水広明・村田裕介・辻田義治・武井美幸・木下隆利: "固体高分解能^<13>C NMR法によるエチレンアイオノマーの構造解析" 第32回NMR討論会講演要旨集. 13-14 (1993)

Hiroaki Yoshimizu、Yusuke Murata、Yoshiharu Tsujita、Miyuki Takei 和 Takatoshi Kinoshita：“通过固态高分辨率^ 13 C NMR 方法进行乙烯离聚物的结构分析”第 32 届 NMR 研讨会摘要 13-14 (1993)。

H.Okumura, et al.: "Relationship Between Crystalline Phase and the Mechanical Property of Ethylene ionomer" Polym.Prep.Vol.43(in press). (1993)

H.Okumura 等人：“结晶相与乙烯离聚物机械性能之间的关系”Polym.Prep.Vol.43（印刷中）。

H.Yoshimizu, et al.: "Molecular Dynamics of Ethylene-Methacrylic Acid Copolymer and its ionomers" Polym.Prep.Vol.41. 4442-4444 (1992)

H.Yoshimizu 等人：“乙烯-甲基丙烯酸共聚物及其离聚物的分子动力学”Polym.Prep.Vol.41。

Y.Murata, et al.: "A Structural Study of Ethylene ionomer by Solid-State NMR" Polym.Prep.Vol.43(in press). (1993)

Y.Murata 等人：“通过固态 NMR 对乙烯离聚物进行结构研究”Polym.Prep.Vol.43（印刷中）。