STUDY ON PHASE TRANSITION AND CRITICAL PHENOMENA IN POLYMER CRYSTALS BASED ON LIGHT-HEATING MODULATED DTA AND HIGH PRESSURE MEASUREMENT

基于光热调制差热分析和高压测量的聚合物晶体相变和临界现象研究

• 批准号: 14340122
• 负责人: ITOH Takashi
• 金额: $ 8.77万
• 依托单位: KYOTO INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14340122/
• 关键词: LIGHT-HEATING MODULATED DTA UNDER HIGH PRESSURE; PHASE TRANSITION; CRITICAL PHENOMENA; NYLON CRYSTALS; VINYLIDENE FLUORIDE-TRIFLUOROETHYLENE COPOLYMER CRYSTALS; HIGH-PRESSURE X-RAY ANALYSIS SYSTEM; AMORPHOUS NYLON 6; FERROELECTRICITY; 高温高圧下比熱測定

There had been no reports in the world, which strictly proved appearance of second-order phase transition in polymer crystals. We recently discovered the second-order phase transition in polyamide crystals on the basis of X-ray structure analysis under high-pressure. Through such studies, we noticed that the quantitative analysis had not been performed for specific-heat measurement under high-pressure in the world, which must give us one of the most important information to discuss the phase-transitional phenomena in material. It is the reason why we started this project.The first step of this project is to construct the high-pressure system of light-heating modulated temperature DTA(HP-LMTDTA) to perform the dynamical thermal measurement of polymers. After construction, we examined performance of the system by using the phase-transitional phenomena of 1,4-trans-polybutadiene crystal to prove it possible to measure the thermal property for the dynamical process during the phase transit … More ion under high-pressure up to 300 Mpa.Through this project, we mainly analyzed the phase-transitional phenomena in nylon and fluoro-copolymer crystals to show that the first- and/or second-order phase transition occurs only in nylon 6Y (Y : even number ≦8) crystals even under normal and high pressure. It was also found that structural changes in vinylidene fluoride(VDF)-trifluoroethylene(TrFE) copolymer crystals are transformed from continuous (cooled phase(CP) to high-temperature phase(HP)) to discontinuous one (low-temperature phase(LP) to HP) with increasing VDF molar content or external pressure for VDF 65 % sample, where the transition from CP to LP occurs prior to the first-order phase transition from LP to HP. The sample with 65 % of VDF is composed of only CP, and LP suddenly appears in VDF 68 % sample and another LP is suggested to exist in VDF 71 and 77 % samples. Percolation theory may be applicable to explain such structural transformation very sensitive with VDF content.Such results indicate that this system can be applied for various studies under high pressure on polymers at molecular level such as crystal growth and melting, formation process of spherulite, electrical properties etc. Less

目前国际上还没有严格证明聚合物晶体中存在二级相变的报道。我们最近在高压下X射线结构分析的基础上发现了聚酰胺晶体的二级相变。通过这些研究，我们注意到目前国际上还没有对高压比热的测量进行定量分析，这为我们讨论材料中的相变现象提供了重要的信息之一。本课题的第一步是建立高压光热调温差热分析系统（HP-LMTDTA），用于聚合物的动态热测量。构建完成后，我们利用1，4-反式聚丁二烯晶体的相变现象对系统的性能进行了测试，证明了在相变过程中对动态过程的热性质进行测量的可能性 ...更多信息 通过本课题的研究，我们主要分析了尼龙和含氟共聚物晶体中的相转变现象，结果表明：即使在常压和高压下，尼龙6 Y（Y：偶数× 8）晶体也只发生一级和/或二级相转变。研究还发现，对于VDF65%样品，随着VDF摩尔含量的增加或外压的升高，VDF-三氟乙烯（TrFE）共聚物晶体的结构由连续相（冷却相（CP）→高温相（HP））转变为不连续相（低温相（LP）→ HP），其中CP → LP的转变发生在LP → HP的一级相变之前. VDF含量为65%的样品仅由CP组成，而LP在VDF含量为68%的样品中突然出现，在VDF含量为71和77%的样品中可能存在另一LP。逾渗理论可以解释这种对VDF含量非常敏感的结构转变，这些结果表明该系统可以应用于高压下聚合物在分子水平上的各种研究，如晶体生长和熔融，球晶形成过程，电性能等。

项目成果

Heat Flows on the Heating Process after aging of Glassy PMMA Measured by Temperature Modulated DSC

调温 DSC 测量玻璃状 PMMA 老化后加热过程的热流

• 发表时间: 2005
• 期刊: Thermochimica Acta (In press)
• 作者: O.Furuhashi;T.Kinugawa;T.Hirayama;(他3名);K.Kuwahara et al.;Yasuo Saruyama
• 通讯作者: Yasuo Saruyama

Heat Flows on the Heating Process after Aging of Glassy PMMA Measured by Temperature Modulated Differential Scanning Calorimeter

调温差示扫描量热仪测量玻璃状 PMMA 老化后加热过程的热流

• 期刊: Thermochim.Acta (in press)
• 作者: Y.Hidaka;S.Kai;et al.;Yasuo Saruyam
• 通讯作者: Yasuo Saruyam

Susumu Fujiwara: "Molecular dynamics simulation of a single polymer chain in vacuum and in solution"Computer Physics Communications. 147. 342-345 (2002)

Susumu Fujiwara：“真空和溶液中单聚合物链的分子动力学模拟”计算机物理通讯。

Ferroelectricity and Amorphous Structure in Nylon 6

尼龙 6 中的铁电性和非晶结构

• 发表时间: 2005
• 期刊: Polymer Processing(in Japanese) 73-10
• 作者: Takashi Itoh;Teruaki Yanagisawa
• 通讯作者: Teruaki Yanagisawa

Thermal, Structural and Ferroelectric Properties of Amorphous Phases in Quenched Nylon 6 Film

淬火尼龙 6 薄膜中非晶相的热、结构和铁电性能

• 发表时间: 2004
• 期刊: Journal of the Physical Society of Japan 73
• 作者: H.Yagi;K.Takaichi;K.Ueda;Y.Yamasaki;T.Yanagitani;A.Kaminskii;Teruaki Yanagisawa
• 通讯作者: Teruaki Yanagisawa