波谱学杂志 ›› 2023, Vol. 40 ›› Issue (2): 111-121.doi: 10.11938/cjmr20223007

• 研究论文 • 上一篇    下一篇

基于T1-T2*弛豫相关的聚氨酯橡胶相态结构和动力学特征

郭江峰1,2,*(),MACMILLAN Bryce2,BALCOM Bruce2   

  1. 1.油气资源与探测国家重点实验室,中国石油大学(北京),北京 102249,中国
    2.UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
  • 收稿日期:2022-07-11 出版日期:2023-06-05 在线发表日期:2022-08-23
  • 通讯作者: 郭江峰 E-mail:jguo7@cup.edu.cn
  • 基金资助:
    中国石油大学(北京)科研基金(2462022QNXZ001);加拿大国家自然科学和工程研究基金(2015-6122);加拿大首席科学家项目(950-230894)

Insights into the Phase Structure and Dynamics of Polyurethane Rubber Using T1-T2* Relaxation Correlation

GUO Jiangfeng1,2,*(),MACMILLAN Bryce2,BALCOM Bruce2   

  1. 1. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, China
    2. UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
  • Received:2022-07-11 Published:2023-06-05 Online:2022-08-23
  • Contact: GUO Jiangfeng E-mail:jguo7@cup.edu.cn

摘要:

磁共振技术具有非破坏性、对高分子链运动敏感等特点,是一种能够在分子水平上表征高分子系统相态结构和动力学特征的常用技术.本文利用T1-T2*弛豫相关研究了聚氨酯橡胶的相态结构和分子动力学特征,并用高斯衰减和指数衰减模型分析了聚氨酯橡胶的T1-T2*数据.聚氨酯橡胶的T1-T2*谱显示了三种类型的信号:晶体氢组分的T2*最短,过渡相氢组分具有中等的T2*,非晶体氢组分的T2*最长;但这三种氢组分表现出相近的T1,且T1随着聚氨酯橡胶硬度的增加或温度的降低而逐渐降低.三种氢组分的磁共振信号强度随聚氨酯橡胶的硬度和温度的变化而变化.随着聚氨酯橡胶硬度的增加,晶体氢组分含量增加,非晶体氢组分和过渡相氢组分的含量降低;随着温度的增加,晶体氢组分含量减少,过渡相氢组分含量保持不变,而非晶体氢组分含量增加.另外,聚氨酯橡胶的硬软比随温度的升高而降低.这些结果表明T1-T2*弛豫相关可用于聚氨酯橡胶的相态结构和动力学评价.

关键词: 核磁共振, T1-T2*弛豫相关, 聚氨酯橡胶, 相态结构, 动力学特征

Abstract:

Nuclear magnetic resonance (NMR) is a non-destructive technique that can reveal the phase structure and dynamics of polymers at the molecular level. It is sensitive to polymer chain mobility and requires minimal special sample preparation. We investigated the phase structure and molecular dynamics of polyurethane rubber (PUR) based on the T1-T2* relaxation correlation spectra, and analyzed the T1-T2* data by multi modal decay. The T1-T2* spectra showed three types of signals: rigid 1H with the shortest T2* value, interphase 1H with an intermediate T2* value, and mobile-amorphous 1H with the longest T2* value. The three 1H components exhibit the similar T1 values in PUR, which decreased with increasing hardness or decreasing temperature. The integrals of these signals depend on the durometer hardness and temperature for PUR. They increase for the rigid phase but reduce for mobile-amorphous phase and interphase with an increase of PUR durometer hardness. The rigid 1H component decreased and the mobile-amorphous 1H component increased with increasing temperature, while the interphase 1H component remained constant. In addition, the hard/soft ratio decreased with increasing temperature for PUR systems. These results indicated that T1-T2* spectra can be used to characterize phase structure and dynamics of PUR.

Key words: nuclear magnetic resonance, T1-T2* relaxation correlation, polyurethane rubber, phase structure, dynamics

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