Glass Transition Temperature of Poly(tert-butyl methacrylate) Langmuir−Blodgett Film and Spin-Coated Film by X-ray Reflectivity and Ellipsometry

Abstract

The glass transition temperature (Tg) of poly(tert-butyl methacrylate) (PtBMA) Langmuir-Blodgett (LB) films relative to that of spin-coated films on a silicon substrate is investigated by ellipsometry and X-ray reflectivity. The Tg of spin-coated films on an oxide-free silicon wafer decreases as the film thickness decreases, which is consistent with the majority of the previous reports in the literature. However, the transition temperature of the LB films is nearly independent of the total thickness, that is, the number of accumulated layers, which is much different from the case for spin-coated films. After sufficient thermal annealing of the LB film, it recovers the thermal transition behavior of the spin-coated film with an equivalent thickness. The layer structure of the LB film is deemed to be responsible for the departure from the behavior of the spin-coated film.

In Situ Probing the Relaxation Properties of Ultrathin Polystyrene Films by Using Electric Force Microscopy

“…It is regarded that the dead layer in the three-layer model has almost no mobility [22]. Therefore, the shift of T g is contributed both by surface layer ( T sur f g) and bulk layer ( T bulk g), in which the surface layer is thought as a region of enhanced mobility [28, 29]. Polymer chain ends at the air-polymer interface tends to move toward the surface, which leads to the increase of free volume and acceleration of chain mobility [30].…”

Synthesis, characterisation and flame, thermal and electrical properties of poly (n-butyl methacrylate)/titanium dioxide nanocomposites

“…Polymers with the butyl methacrylate group have been particularly of interest, because the glass transition temperature of butyl methacrylate (PBMA) is relatively lower than that of methacrylate (PMMA) polymers [12,13]. Due to its transparency and easy processability, PBMA can be used as a polymer matrix for synthesis of different nanocomposites.…”

Influence of the Polymethacrylate Chain Conformation in Langmuir–Blodgett–Kuhn Films on the Glass-Transition Temperature

“…Recently, See et al reported similar T g dependencies determined from X-ray reflectometry (XR) measurements for LBK multilayers made from poly(tert-butyl methacrylate) and the corresponding spincoat samples. [5] Mabuchi et al determined via energy-transfer measurements the onset temperature for chain relaxation in LBK films made from poly(vinylalkanal acetal) to be close to the T g of the bulk material. [6] In the following, a detailed study of LBK multilayers made from poly(ethyl methacrylate) PEMA is reported.…”