Low-energy vibrational density of states of plasticized poly(methyl methacrylate)

Abstract

The low-energy vibrational density of states (VDOS) of hydrogenated or deuterated poly(methyl methacrylate) (PMMA) plasticized by dibutyl phtalate (DBP) is determined by inelastic neutron scattering. From experiment, it is equal to the sum of the ones of the PMMA and DBP components. However, a partition of the total low-energy VDOS among PMMA and DBP was observed. Contrary to Raman scattering, neutron scattering does not show enhancement of the boson peak due to plasticization.2

Raman spectroscopy studies of Er3+-doped zinc tellurite glasses

“…In the region of the Boson peak, the observed vibrational modes are localized in blobs or structural domains, named more cohesive domains, that are separated from each other by less cohesive interfacial zones [16]. The intensity of the Boson peak is related to the inhomogeneous cohesion; the more contrast in the cohesion on the nanoscale, the more intense is the boson peak [17]. Rare-earth ions are assumed to be incorporated at non-bridging anion bond sites (interfacial zones), which dominate the rareearth environment.…”