Glass transition studies in physically aged partially crystalline poly(ethylene terephthalate) by TSC

Corona Charging and Thermal Sampling of Stretched Poly(vinyl Chloride)

“…This behavior is associated with the decrease of the total amorphous fraction, that is an increase in the crystallinity degree has occured [16]. As shown in Figure 5, the maximum of the a-relaxation is located at T ¼ 359 K. To isolate the a-peak from any sub-T g relaxation overlap, the low temperature tail of the peak is partially cleaned and the resulting peak is shown in the figure.…”

TSDC spectroscopy of relaxational and interfacial phenomena

“…The titania phase in titania-containing samples (at C TiO 2 ≥ 50 wt. %) consists of a blend of anatase and rutile at C anatase /C rutile between 7.3 (AST 50 ) and 0.84 (ST 65 ). In the case of low amounts of titania in ST, the titania phase is primarily anatase with a minor contribution of amorphous oxide distributed in the silica matrix.…”

“…The problem of the glass transition was studied and discussed for many systems such as pentachloronitrobenzene [62], polyarylate [63,64], poly(ethylene terephthalate) [65], resins [66,67], confined liquids [68], and liquid crystals [69]. It is important to analyse the molecular mobility at the glass transition [70] by TSDC and DRS measurements.…”

New Insights into the Effects of Physical Aging on Glass Transition of Polystyrene by FTIR

“…[2] Below T g , the glass is considered to be in a nonequilibrium state, and has excess thermodynamic factors over equilibrium values such as volume, enthalpy, and entropy and there will be a driving force to reduce these toward the equilibrium values at that temperature. [2][3][4] This relaxation process of the chains from nonequilibrium to equilibrium state is called enthalpic relaxation or physical aging. [3] As is well known, the glass transition behaviors of polymers are closely related to their thermal histories; therefore, their T g values will also change with physical aging.…”

“…[5] The effects of physical aging on the glass transition have been studied by numerous researchers with various methods. [3][4][5][6][7][8][9][10][11][12][13][14][15] Fourier transform infrared (FTIR) spectroscopy is useful for investigating the conformation and inter and intramolecular interactions of polymers. Therefore, it can not only determine the T g value but also interpret the glass transition behaviors in terms of conformation angles and molecule interactions.…”