压力诱导丙烯酸聚合：拉曼光谱研究。

Pressure-induced polymerization of acrylic acid: a Raman spectroscopic study.

机构信息

Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.

出版信息

J Phys Chem B. 2010 Aug 5;114(30):9744-50. doi: 10.1021/jp1034757.

PMID:20617845

Abstract

We report here the first in-situ Raman spectroscopic study of pressure-induced structural and polymeric transformations of acrylic acid. Two crystalline phases (I and II) were observed upon compression to approximately 0.3 and approximately 2.7 GPa. Phase I can be characterized with a single s-cis molecular conformation with possibly a similar structure to the low-temperature phase, while phase II suggests significantly enhanced molecular interactions toward polymerization and structural disordering. Beyond approximately 8 GPa, spectroscopic features indicate the onset of polymerization. The high-pressure polymeric phase together with the pressure-quenched materials was examined and compared with two commercial acrylic acid polymers using Raman spectroscopy. The characteristics of polymeric acrylic acid and their transformation mechanisms as well as the implications of hydrogen-bonding interactions are discussed.

摘要

我们在这里报告了丙烯酸的结构和聚合态在压力下转变的首例原位拉曼光谱研究。在压缩到约 0.3 和 2.7 GPa 时，我们观察到两种晶相（I 和 II）。在压缩到约 0.3 和 2.7 GPa 时，我们观察到两种晶相（I 和 II）。在压缩到约 0.3 和 2.7 GPa 时，我们观察到两种晶相（I 和 II）。相 I 可以用单一的 s-cis 分子构象来描述，其结构可能类似于低温相，而相 II 则表明分子间相互作用显著增强，朝着聚合和结构无序化的方向发展。在大约 8 GPa 以上，光谱特征表明聚合作用开始。使用拉曼光谱对高压聚合相以及高压淬火材料进行了研究，并与两种商业丙烯酸聚合物进行了比较。讨论了聚合型丙烯酸的特性及其转变机制以及氢键相互作用的影响。