Dynamics of the Polymer Chain End

2014 Fiscal Year Final Research Report

• Project/Area Number: 25810072
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Polymer chemistry
• Research Institution: Gifu University
• Principal Investigator: MIWA Yohei 岐阜大学, 工学部, 助教 (10635692)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 高分子末端 / 重水素ラベル / 赤外分光 / ガラス転移 / 伸縮振動

Outline of Final Research Achievements

Glass transition temperature (Tg) and vibrational properties at the chain end of polystyrene (PS) were selectively determined utilizing Fourier transform infrared (FT-IR) spectroscopy. In this method, PSs selectively deuterated at the midchain (M-PS) or the chain end (E-PS) were synthesized and the asymmetric stretching vibration of the main chain CD2 (Vas(CD2)) were analyzed in detail. We found that the temperature dependence of the Vas(CD2) frequency shows a clear inflection at the calorimetric Tg of PS. The inflection temperature was defined as Tg(FTIR), which represents the Tg at the local region around the deuterated sites. Although higher segmental mobility at the chain end had been shown above the Tg in our earlier work, this study found that the Tg(FTIR)s of the M-PS and E-PS are the same. On the other hand, the Vas(CD2) frequency of the E-PS was by a few cm-1 higher than that of the M-PS because of reduced interactions between repeat units along the chain at the chain end.

Free Research Field

高分子科学