Session P25: Focus Session: Dynamics and Structure in Polymer Melts and Glasses
11:15 AM–2:03 PM, Wednesday, March 7, 2007
Colorado Convention Center Room: 203
Sponsoring Unit:
DPOLY
Chair: Ramanan Krishnamoorti, University of Houston
Abstract ID: BAPS.2007.MAR.P25.11
Abstract: P25.00011 : Probing Chain Entanglement in Polymer Glasses in Sub-nano Level
1:39 PM–1:51 PM
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Abstract 
Authors:
Gi Xue
Xiaoliang Wang
Dongshan Zhou
(Department of Polymer Science and Engineering, Nanjing University)
Pinchuan Sun
(College of Chemistry, Nankai University)
A new approach to characterize the chain distance of polymer glasses in isotopic blends using a dipolar filter NMR experiment was developed using ultra fast magic angle spinning (MAS) to selectively enhance sensitivity and resolution of the signals corresponding to the entanglement region. When the deuterated chain entangles with the hydrogenous one within 0.8 nm, the strong 1H dipolar interaction will be diluted. Ultra fast MAS (25-kHz) is used to further average the residual dipolar interaction in the entanglement region. And a dipolar filter experiment is used to suppress the signals from strong 1H-1H dipolar interactions that exist in hydrogenated polymer chains. Based on the above three aspects, an unique 1H signal enhancement effect was found selectively in the overlapping region where the distance between two chains is shorter than 0.8 nm, which can be used as a sensitive probe to characterizing the entanglements in sub-nano level.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.MAR.P25.11