TY - JOUR
T1 - Crosslink network rearrangement via reactive encapsulation of solvent in epoxy curing
T2 - A combined molecular simulation and experimental study
AU - Jang, Changwoon
AU - Sharifi, Majid
AU - Palmese, Giuseppe R.
AU - Abrams, Cameron F.
N1 - Funding Information:
This work has been supported by the Cooperative Agreement between the Materials in Extreme Dynamic Environments (MEDE) Consortium and US Army Research Lab . Army Research Lab under Contract No. W911NF-12-2-0022 . This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number OCI-1053575 (allocations TG-MCB070073N and TG-CHE130061). We would like to acknowledge Drs. Timothy Sirk and Jan Andzelm of the Army Research Laboratory for helpful discussions.
PY - 2014/8/5
Y1 - 2014/8/5
N2 - Encapsulation of solvent during cure is proposed as one way to alter the network topology of crosslinked polymers. We performed all-atom molecular dynamics simulations to study systems comprised of Epon828 epoxy resin and Jeffamine-D400 diamine crosslinkers cured with varying amounts of the inert solvent dichloromethane (0-50 wt%) and then dried and annealed. Densities, glass transition temperatures, and Young's moduli are observed to be insensitive to the initial amount of dichloromethane. These findings were verified by experiment. Simulations also showed that radial distribution functions and dihedral angle distributions were insensitive to the amount of dichloromethane present. However, using Dijkstra's algorithm, we observed that the distribution of minimum path lengths between crosslinks shifts appreciably to larger values as the amount of dichloromethane increases. This suggests that solvent-encapsulated curing can allow for control over network topology without changing crosslink density or intermolecular packing, and the properties derived from it, in highly crosslinked polymers.
AB - Encapsulation of solvent during cure is proposed as one way to alter the network topology of crosslinked polymers. We performed all-atom molecular dynamics simulations to study systems comprised of Epon828 epoxy resin and Jeffamine-D400 diamine crosslinkers cured with varying amounts of the inert solvent dichloromethane (0-50 wt%) and then dried and annealed. Densities, glass transition temperatures, and Young's moduli are observed to be insensitive to the initial amount of dichloromethane. These findings were verified by experiment. Simulations also showed that radial distribution functions and dihedral angle distributions were insensitive to the amount of dichloromethane present. However, using Dijkstra's algorithm, we observed that the distribution of minimum path lengths between crosslinks shifts appreciably to larger values as the amount of dichloromethane increases. This suggests that solvent-encapsulated curing can allow for control over network topology without changing crosslink density or intermolecular packing, and the properties derived from it, in highly crosslinked polymers.
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U2 - 10.1016/j.polymer.2014.06.022
DO - 10.1016/j.polymer.2014.06.022
M3 - Article
AN - SCOPUS:84905485545
SN - 0032-3861
VL - 55
SP - 3859
EP - 3868
JO - Polymer
JF - Polymer
IS - 16
ER -