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Determination of primary bond scissions by mass spectrometric analysis of ultrasonic degradation products of poly(ethylene oxide‐block‐propylene oxide) copolymers |
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| Authors: | Takehiro Watanabe Masanori Okabayashi Daisuke Kurokawa Yukari Nishimoto Tomoyuki Ozawa Hideya Kawasaki Ryuichi Arakawa |
| Institution: | 1. Department of Chemistry and Materials Engineering, Kansai University, Suita, Osaka 564‐8680, Japan;2. Central Research Laboratory, The Nippon Synthetic Chemical Industry Co. Ltd., Ibaraki, Osaka 567‐0052, Japan;3. Chemical Research Laboratories, Nissan Chemical Industries Ltd., Funabashi, Chiba 274‐8507, Japan |
| Abstract: | Ultrasonic degradation of poly(ethylene oxide‐block‐propylene oxide) copolymers consisting of a hydrophilic and a hydrophobic portion was studied with the aim to determine the location of bonds involved in the initial scission of the copolymers. LC–APCI‐IT‐MS and LC–APCI‐orbitrap‐MS were used for the detailed structural analysis of degradation products. The results indicated that initial bond scissions occurred principally at the boundary regions between backbones of polyethylene oxide (PEO) and polypropylene oxide (PPO) chains. Further structural analysis revealed the presence of oxygen adducts in the degradation products. Comparison with a thermal degradation carried out in helium atmosphere, one can conclude that the oxygen adducts are formed by radical reaction with water or dissolving oxygen molecules. The study demonstrated that chemical reactions as well as physical bond stress scissions are involved in the ultrasonic degradation of the copolymers. Copyright © 2010 John Wiley & Sons, Ltd. |
| Keywords: | poly(ethylene oxide‐block‐propylene oxide) ultrasonic degradation thermal degradation MALDI‐TOF‐MS LC‐APCI‐IT‐MS LC‐orbitrap‐MS high resolution mass spectrometry |