INVESTIGADORES
VEGA Daniel Alberto
artículos
Título:
Viscoelastic response of linear defects trapped in polymer networks
Autor/es:
ROTH LE; AGUDELO C; RESSIA J; GOMEZ LR; EM VALLES; VILLAR MA; DA VEGA
Revista:
EUROPEAN POLYMER JOURNAL
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2015 vol. 64 p. 1 - 9
ISSN:
0014-3057
Resumen:
We analyze the dynamic response of end-linked poly(dimethylsiloxane) networks containing
entangled unattached guest linear polymers. Upon increasing the content of unattached
guest polymers there is an increasing dissipation and a reduction in the network
elasticity. It was found that the width of the relaxation spectrum is nearly insensitive to
the content of guest chains, indicating that the network structure is not affected by the
presence of these defects and that the effective number of entanglements associated to
guest chains is independent of the equilibrium elastic modulus of the networks.
The inhibition of the constraints release mechanism for molecules trapped in polymer
networks have enormous consequences on the dynamic response, producing a dramatic
slowing down in the relaxational dynamics of defects. The presence of different structures
of defects in polymer networks is physically unavoidable, even under optimum reaction
conditions. Here we found that the slow dynamics of soluble branched structures or dangling
molecules can easily hide the contribution of linear unattached molecules.