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化学学报
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化学学报 ›› 2006, Vol. 64 ›› Issue (13): 1324-1328. 上一篇    下一篇

研究论文

二维红外相关光谱研究缠结对冷冻升华无规聚苯乙烯分子运动的影响

孙冰洁1，武培怡*,1，范仲勇2   

  1. (1复旦大学高分子科学系 聚合物分子工程教育部重点实验室 上海 200433)
    (2复旦大学材料科学系 上海 200433)
  • 投稿日期:2005-06-30 修回日期:2006-03-20 发布日期:2006-07-14
  • 通讯作者: 武培怡

Two-Dimensional (2D) FTIR Spectroscopic Study on Influence of Entanglements on Movements of Freeze-dried Atactic Polystyrene Molecules

SUN Bing-Jie1, WU Pei-Yi*,1, FAN Zhong-Yong2   

  1. (1 Department of Macromolecular Science and Key Laboratory of Molecular Engineering of Polymers, Ministry of Education,
    Fudan University, Shanghai 200433)
    (2 Department of Materials Science, Fudan University, Shanghai 200433)
  • Received:2005-06-30 Revised:2006-03-20 Published:2006-07-14
  • Contact: WU Pei-Yi

PDF

910

被引次数

28

用冷冻升华法制备了浓度为1×10－4 和2×10－5 g/mL的单链无规聚苯乙烯(a-PS). 利用FTIR测试方法, 测定a-PS在等温处理时红外吸收峰的时间依赖性与温度依赖性, 研究样品中链缠结和链结构单元的堆积等因素对红外吸收峰的影响, 进而探讨链缠结对a-PS分子运动的影响. 同时, 也通过二维相关分析来研究a-PS等温实验过程中, 链缠结的变化情况以及官能团之间的变化顺序, 推断在a-PS等温时, 与链结构单元的堆积相联系的苯环振动首先发生, 其次才是与链缠结相关联的CH2振动发生变化, 并由此确定缠结对冷冻升华a-PS分子运动的影响.

关键词: 无规聚苯乙烯, 冷冻升华, 红外光谱, 缠结, 二维相关分析

In order to learn the influence of entanglements and other factors on the structural changes of atactic polystyrene, freeze-dried single-chain samples were prepared from dilute solutions of atactic polystyrene (a-PS) in benzene at different concentrations (1×10－4 and 2×10－5 g/mL). In this study, the annealing process of the above-mentioned samples at various temperatures for different periods of time has been investigated using Fourier transform infrared (FTIR). According to the IR spectroscopy, when annealing at the temperature of 210 ℃, the peak area of δ(CH2) bands first decreased gradually and did not change any more till some certain moment. That is because during annealing, the a-PS chains got together and their entanglements increased gradually and finally approach to a stable configuration like the bulk sample. The concentration and temperature dependent of the entanglements are also discussed in this study. The results of FTIR spectra were further analyzed by two-dimensional (2D) correlation method to study the intra- and inter-chain entanglements of the a-PS samples. The asynchronism of the bands assigned to the vibration of benzene ring and CH2 bending bands indicates that during the annealing process the accumulation of chain structure occurs earlier than the intra- and inter-chain entanglements of the above-mentioned a-PS samples.

Key words: atactic polystyrene, freeze-dried, infrared spectroscopy, entanglement, two-dimensional correlation analysis