Nano Science and Technology InstituteNano Science and Technology Institute
Nano Science and Technology Institute 2005 NSTI Nanotechnology Conference & Trade Show
Nanotech 2005
Bio Nano 2005
Business & Investment
Nano Impact Workshop
Program
Sessions
Sunday
Monday
Tuesday
Wednesday
Thursday
Index of Authors
Index of Keywords
Keynote Presentations
Confirmed Speakers
Participating Companies
Industry Focus Sessions
Nanotech Expo
Special Symposia
Conferences
Sponsors
Exhibitors
Venue 2005
Organization
Press Room
Subscribe
Site Map
Nanotech 2005 At A Glance
Nanotech Proceedings
Nanotechnology Proceedings
Global Partner
nano tech
Supporting Organizations
Nanotech 2005 Supporting Organization
Media Sponsors
Nanotech 2005 Medias Sponsors
Event Contact
696 San Ramon Valley Blvd., Ste. 423
Danville, CA 94526
Ph: (925) 353-5004
Fx: (925) 886-8461
E-mail:
 
 

Viscoelastic Relaxation and Molecular Mobility of Hyperbranched Poly(epsilon-caprolactone)s in Their Melt State

H.J. Song, J. Choi and S-Y Kwak
Seoul National University, KR

Keywords:
hyperbrached poly(epsilon-caprolactone), dynamic viscoelastic relaxation, molecular mobility, correlation time, activation energy

Abstract:
The dynamic viscoelastic relaxation behavior and the molecular mobility of hyperbranched poly(epsilon-caprolactone)s (HPCLs) possessing the molecular architectural variation and their linear counterpart, linear poly(epsilon-caprolactone) (LPCL), were characterized and evaluated in conjunction with their specific molecular architectures which are the different lengths of the linear backbone segments and the different relative degrees of branching (DBs). The relative DBs, determined by the branching ratio values, were in decreasing order of HPCL–5 > HPCL–10 > HPCL–20. Dynamic viscoelastic relaxation measurements exhibited unentangled behavior for HPCLs compared to the apparently entangled linear, and the parallel G'(_) and G''(_) curves were observed for the HPCLs, while the LPCL exhibited a typical curve. This characteristic dynamic behavior of HPCLs, particularly incorporating the shorter segments, can be seen to be another example of gel-like power-law relaxation of hyperbranched systems. The correlation time, tauc, was determined the empirical Havriliak-Negami equation. Further insights to the correlation times with the Arrhenius equation provided novel information about the temperature-dependence of the molecular mobility and the activation energy, Ea. The molecular mobility of three HPCLs was found to be higher than that of LPCL, and was observed to enhance with decreasing lengths of oligo(epsilon-caprolactone) segments and increasing relative DB.

Back to Program

Sessions Sunday Monday Tuesday Wednesday Thursday Authors

Nanotech 2005 Conference Program Abstract

 
Gold Sponsors
Nanotech Gold Sponsors
Silver Sponsors
Nanotech Silver Sponsors
Gold Key Sponsors
Nanotech Gold Key Sponsors
Nanotech Ventures Sponsors
Nanotech Ventures Sponsors
Sponsors
Nanotech Sponsors
News Headlines
NSTI Online Community
 
 

© Nano Science and Technology Institute, all rights reserved.
Terms of use | Privacy policy | Contact