IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
artículos
Título:
Contribution of Linear Guest and Structural Pendant Chains to Relaxational Dynamics in Model Polymer Networks Probed by Time-Domain 1H NMR
Autor/es:
F. CAMPISE; M.A. VILLAR; D.A. VEGA; L.E. ROTH; E.M. VALLÉS; R.H. ACOSTA; G.A. MONTI
Revista:
MACROMOLECULES
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: Washington; Año: 2016 vol. 49 p. 387 - 394
ISSN:
0024-9297
Resumen:
A series of end-linked polymer networks withvarying contents of linear guest chains were investigatedthrough swelling and time-domain NMR temperature dependentexperiments. Taking advantage of the thermorheologicalsimplicity of polydimethylsiloxane polymers, time−temperaturesuperposition (TTS) was employed to expand thecharacteristic time scales of NMR exploration by about 2orders of magnitude. A comparison between swelling data andtube model predictions reveals that NMR captures thedominant features of the equilibrium and dynamic propertiesof defects trapped in slightly cross-linked, entanglementdominatedpolymer networks. As high-temperature experimentsensures a complete relaxation of the guest linear chains on the millisecond time scale of the NMR experiments, an accuratedescription of the network architecture can be provided. Contents of guest chains determined by NMR were found to agreewithin a 1 wt % accuracy with data of swelling experiments