Phenylene Ring Motions In Isomeric Glassy Epoxy Networks and Their Contributions to Thermal and Mechanical Properties

Authors

Jianwei Tu, University of Southern Mississippi
Samuel J. Tucker, University of Southern Mississippi
Stephen Christensen, University of Southern Mississippi
Abdelwahed R. Sayed, University of Southern MississippiFollow
William L. Jarrett, University of Southern Mississippi
Jeffrey S. Wiggins, University of Southern MississippiFollow

Document Type

Article

Publication Date

3-24-2015

School

Polymer Science and Engineering

Abstract

Cross-linked epoxies prepared from diglycidyl ether of bisphenol A (DGEBA) exhibit substantial property differences due to isomeric structures of the diamine curatives, 3,3′- and 4,4′-diaminodiphenyl sulfone (DDS). Here, the motions of phenylene rings on both the bisphenol A (BPA) and DDS structures of the networks were investigated through solid-state NMR ²H line shape analysis to trace the molecular origins. Ring deuterated monomers, namely, DGEBA-d₈, 33DDS-d₈, and 44DDS-d₈, were synthesized, and four deuterated networks were prepared. The line shapes of the ring motions were interpreted using a motional model that described both ring π-flips and main-chain fluctuations. The contributions of different ring motions to mechanical relaxations are elucidated, and the molecular origins of property differences are identified.

Publication Title

Macromolecules

Volume

48

Issue

6

First Page

1748

Last Page

1758

Recommended Citation

Tu, J., Tucker, S., Christensen, S., Sayed, A., Jarrett, W., Wiggins, J. (2015). Phenylene Ring Motions In Isomeric Glassy Epoxy Networks and Their Contributions to Thermal and Mechanical Properties. Macromolecules, 48(6), 1748-1758.
Available at: https://aquila.usm.edu/fac_pubs/18651