Isothermal Physical Aging of Poly(ethyl methacrylate)/Polyhedral Oligomeric Silsequioxanes Nanocomposite Thin Films

The effects of the polyhedral oligomeric silsequioxanes (POSS) in stacked poly(methyl methacrylate) (PMMA) film samples were investigated in two different film thicknesses, ~50 and ~660 nm. The types of the POSS include methacryl-, octaisobutyl-, and octasilane-POSS. The glass transition temperature (Tg) and isothermal physical aging was depressed by the reduction of film thickness. Among POSS molecules used in this work, methacryl-POSS was the greatest effect in both Tgand relaxation enthalpy (DHRelax) due to the physical aging. The Kohlrausch-Williams-Watts (KWW) relaxation function was used to further understand the effect of POSS and film thickness on the physical aging.

Download Full-text

Size and pressure effects on glass transition temperature of poly (methyl methacrylate) thin films

Thin Solid Films ◽

10.1016/j.tsf.2005.10.001 ◽

2006 ◽

Vol 497 (1-2) ◽

pp. 333-337 ◽

Cited By ~ 6

Author(s):

X.Y. Lang ◽

G.H. Zhang ◽

J.S. Lian ◽

Q. Jiang

Keyword(s):

Thin Films ◽

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Methyl Methacrylate ◽

Pressure Effects ◽

Poly Methyl Methacrylate

Download Full-text

Glass Transition Temperature and Conformational Changes of Poly(methyl methacrylate) Thin Films Determined by a Two-Dimensional Map Representation of Temperature-Dependent Reflection−Absorption FTIR Spectra

Langmuir ◽

10.1021/la020258y ◽

2002 ◽

Vol 18 (15) ◽

pp. 5953-5958 ◽

Cited By ~ 37

Author(s):

Hyeon Suk Shin ◽

Young Mee Jung ◽

Tae Young Oh ◽

Taihyun Chang ◽

Seung Bin Kim ◽

...

Keyword(s):

Thin Films ◽

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Methyl Methacrylate ◽

Conformational Changes ◽

Ftir Spectra ◽

Two Dimensional ◽

Temperature Dependent ◽

Poly Methyl Methacrylate

Download Full-text

Glass Transition Temperature Of Ultrathin Polymer Films On Silicon

MRS Proceedings ◽

10.1557/proc-381-147 ◽

1995 ◽

Vol 381 ◽

Cited By ~ 1

Author(s):

Wen-Li Wu ◽

William E Wallace ◽

John Van Zanten

Keyword(s):

Thin Films ◽

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Film Thickness ◽

Substrate Surface ◽

Silicon Surfaces ◽

X Ray ◽

Molecular Weights ◽

Ultrathin Polymer Films

AbstractThe glass transition temperature, Tg, of polystyrene (PS) thin films on silicon wafers with different surface preparations was determined in order to explore the effect of interfacial interaction energy on local chain dynamics. To enhance interface behavior, the film thickness included in this work was as low as 50 Å. PS with monodisperse molecular weights was chosen as a model polymer. Two different silicon surfaces were prepared: sulfuric acid-clean and hydrogen passivated. Tg of thin films was determined by monitoring the film thickness as a function of temperature. Tgwas identified as the temperature where the thermal expansion coefficient underwent an abrupt change. X-ray reflectivity was used to determine film thickness with a precision of a few angstroms. Tg of PS was found to depend strongly on the initial film thickness, as well as the substrate surface.

Download Full-text

Glass Transition Temperature and Isothermal Physical Aging of PMMA Thin Films Incorporated with POSS

Polymer Korea ◽

10.7317/pk.2012.36.4.507 ◽

2012 ◽

Vol 36 (4) ◽

pp. 507-512 ◽

Cited By ~ 1

Author(s):

Sil-O Jin ◽

Jong-Keun Lee

Keyword(s):

Thin Films ◽

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Physical Aging

Download Full-text

Physical Aging Behavior of a Glassy Polyether

Polymers ◽

10.3390/polym13060954 ◽

2021 ◽

Vol 13 (6) ◽

pp. 954

Author(s):

Xavier Monnier ◽

Sara Marina ◽

Xabier Lopez de Pariza ◽

Haritz Sardón ◽

Jaime Martin ◽

...

Keyword(s):

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Physical Aging ◽

Glassy State ◽

Aging Behavior ◽

Scanning Calorimetry ◽

Narrow Temperature Range ◽

Glass Forming ◽

Fast Scanning Calorimetry

The present work aims to provide insights on recent findings indicating the presence of multiple equilibration mechanisms in physical aging of glasses. To this aim, we have investigated a glass forming polyether, poly(1-4 cyclohexane di-methanol) (PCDM), by following the evolution of the enthalpic state during physical aging by fast scanning calorimetry (FSC). The main results of our study indicate that physical aging persists at temperatures way below the glass transition temperature and, in a narrow temperature range, is characterized by a two steps evolution of the enthalpic state. Altogether, our results indicate that the simple old-standing view of physical aging as triggered by the α relaxation does not hold true when aging is carried out deep in the glassy state.

Download Full-text