The anomalies of glassy polymers at nanoscale from the continuum mechanics perspective

Glassy polymers confined at nano‐scale do exhibit anomalous thermo‐viscoelastic behavior in respect to their bulk response. For example, in ultra‐thin polymer films both negative coefficient of thermal expansion (NCTE) and glass transition temperature (Tg) depression are observed, experimentally. Theoretical conjectures have been drawn that qualitatively explain some features of highly confined glassy polymers [1,2,3] yet quantitative prediction of NCTE and Tg depression would allow a reliable design of devices operating at nano‐scale. In this paper the thin films anomalies are shortly reviewed and their explanation is tempted with classical existing theories.