In Situ Observation of Oriented-Crystallization Process of Rubbers by Electron Microscopy

电子显微镜原位观察橡胶定向结晶过程

• 批准号: 10650886
• 负责人: TSUJI Masaki
• 金额: $ 2.24万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650886/
• 关键词: electron diffraction; dark-field imaging; bright-field defocus-contrast imaging; time-resolved in situ observation; oriented crystallizaion; natural rubber; polychloroprene; isotactic polystyrene; 透過型電子顕微鏡; 電子線回折; 電子回折; 高感度テレビシステム; シシカバブ構造

Oriented-crystallization mechanism for rubbers has been investigated by an "indirect" method, viz. by transmission electron microscope (TEM) observation of their thin films fixed/stained at given stages of crystallization. The purpose of this research is to elucidate the mechanism by "direct" methodssuch as selected-area electron diffraction, bright-field defocus-contrast imaging and dark-field imaging of the films prestretched outside and then crystallized inside a TEM, and by time-resolved in situ TEM observation of the prestretched films during crystallization. The results are as follows :1. Prestretched films were isothermally crystallized one by one inside a TEM; -25℃ for natural rubber (NR) and -5℃ for polychloroprene (CR). In NR, the uniplanar axial orientation was confirmed. In NR and CR, the "α-filament" was identified as an edge-on lamellar crystal. In CR prestretched "quickly" up to a strain of ε=500%, paracrystalline nature was recognized.2. By using our homemade "film-stre … More tching device", highly prestretched NR films (ε=500〜800%) were made. In the case of, e.g. ε=800%, stacked-lamellar structure was recognized after isothermal crystallization at -25℃. On the other hand, thin fibrils of ca. 25nm wide were recognized before isotherml crystallization, but no lamellae were observed. Each fibril was judged to be a "shish" crystal (viz., γ-filament)" or a bundle of shishes.3. Time-resolved in situ observation of 200%-prestretched NR was tried, by repeating TEM observation at -80℃ and crystallization at -25℃. By using our homemade "temperature controller" for a specimen heating holder, in situ observation of growing edge-on lamellae in oriented amorphous films of isotactic polystyrene during crystallization at 150℃ inside a TEM was tried with a TV system. These trials suggested that the time-resolved in situ TEM observation is useful to follow oriented crystallization of polymers.4. On the basis of the above-mentioned results, an oriented-crystallization mechanism for rubbers was proposed. Less

本文用透射电子显微镜（TEM）观察橡胶薄膜在特定结晶阶段的固定/染色，用“间接”方法研究了橡胶的定向结晶机理。本研究的目的是通过选择区电子衍射、明场离焦衬度成像和暗场成像等“直接”方法，以及对预拉伸膜在TEM中结晶过程的时间分辨原位TEM观察，来阐明这一机制。研究结果如下：1.在透射电镜下对预拉伸膜进行逐层等温结晶，天然橡胶（NR）为-25℃，氯丁橡胶（CR）为-5℃。在NR中，确认了单平面轴向取向。在NR和CR中，“α-细丝”被鉴定为边缘上的层状晶体。在CR“快速”预拉伸到ε= 500%的应变时，可识别出次晶性质.通过使用我们自制的“膜应力 ...更多信息 在“蚀刻装置”中，制备了高预拉伸NR膜（ε=500 ~ 800%）。在ε= 800%的情况下，在-25℃等温结晶后识别出叠层结构。另一方面，Ca.在等温结晶前，可观察到25 nm宽的纳米晶，但未观察到纳米晶。每个原纤维被判断为“shish”晶体（即，γ-细丝）”或一束shishes。3.通过在-80℃下重复透射电镜观察和在-25℃下重复结晶，对200%预拉伸天然橡胶进行了时间分辨原位观察。用自制的“温控器”作为试样加热保持器，在透射电镜中，用电视系统对等规聚苯乙烯取向非晶薄膜在150℃结晶过程中的边向层状生长进行了原位观察。这些试验表明，时间分辨TEM原位观察有助于跟踪聚合物的定向结晶.在此基础上，提出了橡胶的取向结晶机理。少

项目成果

M.Tsuji: "In situ TEM observation on crystallization of isotactic polystyrene."Sen'i Gakkai Symp. Prepr.. Vol. 1999(S). S-44 (1999)

M.Tsuji：“等规聚苯乙烯结晶的原位 TEM 观察。”Seni Gakkai Symp.

T.Shimizu,M.Tsuji and S.Kohjiya: "Crystalline Morphologies of Polychloroprene Thin Films as Revealed by Transmission Electron Microscopy." J.Materials Research. 14・4(印刷中). (1999)

T.Shimizu、M.Tsuji 和 S.Kohjiya：“透射电子显微镜揭示的聚氯丁二烯薄膜的晶体形态。”J.Materials Research（1999 年出版）。

Masaki TSUJI: "In situ TEM observation on crystallization of isotactic polystyrene"繊維学会シンポジウム予稿集(Sen'i Gakkai Symp. Prepr. ; 5月10日〜12日 ; 千葉). 1999(S). S-44 (1999)

Masaki TSUJI：“全同立构聚苯乙烯结晶的原位 TEM 观察”Seni Gakkai Prepr.；1999 年 5 月-12 日（S）。

M.Tsuji: "A TEM study on crystalline morphologies of natural rubber and chloroprene rubber (2)."Sen'i Gakkai Prepr. Vol. 1998(G). G-32 (1998)

M.Tsuji：“天然橡胶和氯丁橡胶结晶形态的 TEM 研究 (2)。”Seni Gakkai Prepr。

辻 正樹: "天然ゴムおよびクロロプレンゴムにおける結晶モルフォロジーのTEM観察(2)"繊維学会予稿集(Sen'i Gakkai Prepr.;6月22日〜24日;東京). 1998(G). G-32 (1998)

Masaki Tsuji：“天然橡胶和氯丁橡胶晶体形态的 TEM 观察 (2)” 日本纤维科学技术学会会议记录（Seni Gakkai Prepr.；6 月 22-24 日；东京）。 G-32 (1998)