Berlin 2005 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 9: SYMPOSIUM: Polymer networks and beyond: From molecular structure to materials and biological functions POSTER
CPP 9.16: Poster
Samstag, 5. März 2005, 16:45–18:45, Poster TU D
Disorder effects on the strain response of model polymer networks — •Carsten Svaneborg1, Gary S. Grest2, and Ralf Everaers1 — 1Max-Planck-Institut für komplexer Systeme, Nöthnitzer Str. 38, D-01187 Dresden, Germany — 2Sandia National Laboratories, Albuquerque, NM 87185, USA
Molecular Dynamics simulations are used to investigate polymer networks made by either end-linking or randomly crosslinking a melt of linear precursor chains. The resulting network structures are very different, since end-linking leads to nearly ideal monodisperse networks, while random crosslinking leads to polydisperse networks, characterized by an exponential strand length distribution. Networks with average strand length 20 and 100 were generated. These networks were used to study the effects of disorder in the network connectivity on observables averaged either over the entire network or selected sub-structures. Heterogeneities in the randomly crosslinked networks cause significant differences in the localization of monomers, however, neither the localization of crosslinks nor the microscopic strain response are significantly affected. Compared to end-linked networks, randomly crosslinked networks have a slightly increased tube diameter, and as a result a slightly decreased shear modulus, but otherwise identical stress-strain behavior. For the investigated systems, we conclude that the microscopic strain response, tube diameter, and stress-strain relation are all insensitive to the heterogeneities due to the linking process by which the network were made.