The glass transition behaviour and thermodynamic properties of amorphous polystyrene

Aras, Leyla
Richardson, Maxwell J.
The effect of molecular weight (MW) and thermal history on the heat capacity (cp) of amorphous polystyrene over the temperature range from 200–440 K has been measured using differential scanning calorimetry (d.s.c.) General equations are given that show the influence of MW on cp in both the glassy and liquid states. An enthalpic definition of the glass temperature reflects changes in the glass structure, due to thermal history, that are not found using conventional d.s.c. constructions. Thermodynamic and statistical mechanical theories give reasonable approximations to the observed Tg-MW curve but small systematic deviations are found. The effect of thermal history on Tg can be reproduced using a MW-dependent activation enthalpy.


Understanding the influence of hydrogen bonding and diisocyanate symmetry on the morphology and properties of segmented polyurethanes and polyureas: Computational and experimental study
Sami, Selim; Yıldırım, Erol; Yurtsever, Mine; Yurtsever, Ersin; Yilgor, Emel; Yilgor, Iskender; Wilkes, Garth L. (Elsevier BV, 2014-09-02)
Quantum mechanical calculations (QMC) and dissipative particle dynamics (DPD) siniulations were utilized to understand the nature of the short and long-range hydrogen bonding and its influence on the microphase morphology in segmented polyurethanes and segmented polyureas prepared without chain extenders through the stoichiometric reactions of hydroxy or amine terminated poly(tetramethylene oxide) (PTMO-1000) with 1,4-phenylene diisocyanate (PPDI) and 1,3-phenylene diisocyanate (MPDI). The possibility of lo...
Effect of Boron Phosphate on the Mechanical, Thermal and Fire Retardant Properties of Polypropylene and Polyamide-6 Fibers
DOĞAN, Mehmet; Bayramlı, Erdal (Springer Science and Business Media LLC, 2013-10-01)
The effect of boron phosphate (BPO4) nanoparticles on the mechanical, thermal, and flame retardant properties of polypropylene (PP) and polyamide 6 (PA-6) fibers are investigated by tensile testing, thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), and micro combustion calorimeter (MCC). The addition of BPO4 reduces the mechanical properties of the both PP and PA-6 fibers. According to the TGA results, the addition of BPO4 does not change the thermal behavior of PP fiber and slightl...
The Main Electrical and Interfacial Properties of Benzotriazole and Fluorene Based Organic Devices
Yildiz, Dilber E.; APAYDIN, Dogukan H.; KAYA, Emine; Altindal, Semsettin; Çırpan, Ali (Informa UK Limited, 2013-01-01)
Electrical and interfacial properties of ITO/PEDOT:PSS/poly((9,9-dioctylfluorene)-2,7-diyl(2-dodecyl-benzo[1,2,3]triazole)) (PFTBT)/Au devices were investigated using current-voltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G/w-V) measurements at room temperature. The forward and reverse C-V and G/w-V measurements were carried out in the frequency range of 10kHz-1MHz. The electrical parameters, barrier height (phi Bo ) and ideality factor (n) obtained from the forward bias LnI-V plot were f...
KISAKUREK, D; YIGIT, S (Elsevier BV, 1991-01-01)
Bis(4-bromo-2,6-dichlorophenoxo) ethylenediamine copper(II) complex has been polymerized using electro-initiation by constant potential electrolysis, in dimethylformamide-tetrabutylammonium fluoroborate solvent-supporting electrolyte couple, at room temperature under air or N2. The process leads to low molecular weight (5.6 x 10(3)) linear poly(dichlorophenylene oxide). The structures of the polymers were determined by H-1-NMR and C-13-NMR. The kinetics of the polymerization were followed by in situ cycl...
Studies on the effect of electrode type and substrate temperature on plasma polymerization of two model compounds: Acrylonitrile and hexamethyldisiloxane
Akovalı, Güneri; Dilsiz, Nursel (Wiley, 1990-4)
Polymers were prepared from saturated (HMDS) and unsaturated (AN) monomers in a radio frequency discharge (plasma). The effect of selected parameters such as electrode type (such as Cu, Zn, Ni, Al), reactor type, and substrate temperature (other parameters constant) on chemical structure and the rate of polymer deposition was examined by Fourier transform infrared (FTIR) spectroscopy. Differences in the nature of electrodes and reactor types were found to yield similar plasma products with similar rates of ...
Citation Formats
L. Aras and M. J. Richardson, “The glass transition behaviour and thermodynamic properties of amorphous polystyrene,” Polymer, pp. 2246–2252, 1989, Accessed: 00, 2020. [Online]. Available: