Evaluation of interfacial region of microphase-separated SEBS using modulated differential scanning calorimetry and dynamic mechanical thermal analysis

2017 ◽  
Vol 62 ◽  
pp. 268-277 ◽  
Author(s):  
Nireeksha S. Karode ◽  
Anup Poudel ◽  
Laurence Fitzhenry ◽  
Siobhán Matthews ◽  
Philip R. Walsh ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Dynamic Mechanical Thermal Analysis ◽  
Interfacial Region ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Dynamic Mechanical

Miscibiuty in Blends of Polybenzimidazole and Fluorine Containing Polyimides

1989 ◽  
Vol 171 ◽  
Author(s):  
Hiroaki Yamaoka ◽  
Norman E. Aubrey ◽  
William J. MAcknight ◽  
Frank E. Karasz
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Phase Separation ◽  
Dynamic Mechanical Thermal Analysis ◽  
Room Temperature ◽  
Single Phase ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical

ABSTRACTBlends of polybenzimidazole (PBI) with either of two fluorine-containing polyimides were prepared by casting from solution and by precipitation. Dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) were used to study miscibility in the two blend systems.The blends of PBI with the first polyimide, the polysulfonimide Pl-1, consisted of a single phase when the blends contained less than 30 wt% Pl-1; above 50 wt% Pl-1, phase separation occurred even at room temperature. The PBI blends containing the second polyimide, Pl-2, were immiscible.

scholarly journals Application of Thermal Methods to Analyze the Properties of Coffee Silverskin and Oil Extracted from the Studied Roasting By-Product

2020 ◽  
Vol 10 (24) ◽  
pp. 8790
Author(s):  
Agata Górska ◽  
Rita Brzezińska ◽  
Magdalena Wirkowska-Wojdyła ◽  
Joanna Bryś ◽  
Ewa Domian ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Oxidative Stability ◽  
Reliable Data ◽  
Scanning Calorimetry ◽  
Thermal Methods ◽  
Modulated Differential Scanning Calorimetry ◽  
Coffee Silverskin ◽  
Derivative Thermogravimetry ◽  
Coffee Roasting

The aim of the study was to characterize the thermal properties of coffee silverskin and fat extracted from the material by using differential scanning calorimetry, modulated differential scanning calorimetry and thermogravimetry/derivative thermogravimetry. Additionally, the thermokinetic parameters, oxidative stability and fatty acid composition of the extracted oil were defined. Thermal decomposition of the studied coffee roasting by-product under oxygen occurred in three defined stages. The most significant changes in weight were observed in the region of 200–500 °C and correspond to polysaccharide decomposition. These results are in agreement with the data obtained from the differential scanning calorimetry curve. On the curve course of silverskin, two main exothermic peaks can be observed with a maximum at 265 and 340 °C. These exothermic events represent the transitions of hemicellulose and cellulose. Fat extracted from silverskin turned out to be a source of polyunsaturated fatty acids with the recommended n-6 to n-3 ratio reaching the value 4:1. The studied fat was characterized by low oxidative stability. Considering the obtained results, it can be stated that thermal analysis can provide fast and reliable data concerning the composition and properties of coffee silverskin and coffee silverskin oil.

Glass transformation, heat capacity, and structure of GexSe100−x glasses studied by temperature-modulated differential scanning calorimetry experiments

1997 ◽  
Vol 12 (7) ◽  
pp. 1892-1899 ◽  
Author(s):  
T. Wagner ◽  
S. O. Kasap ◽  
Kouji Maeda
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Heat Flow ◽  
Chalcogenide Glasses ◽  
Glass Transition Region ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Heat Flows ◽  
Glass Transformation

The recent novel temperature-modulated differential scanning calorimetry (DSC) (MDSCTM TA Instruments) technique has been applied to characterize the thermal properties of Ge–Se chalcogenide glasses in the glass transition region. All samples in this work were given the same thermal history by heating to a temperature above the glass transition, equilibrating, and then cooling at a rate of 5 °C/min to a temperature of 20 °C. The reversing and nonreversing heat flows through the glass transformation region during both heating and cooling schedules were measured, and the values of the parameters Tg, ΔH, Cp, and ΔCp, which characterize the thermal events in the glass transition region, were determined. The ability of determining the reversible heat flow in MDSC enables an accurate measurement of the true heat capacity (that normally associated with reversible heat flow), which could not be done hitherto in conventional thermal analysis where the detected heat flow is the total heat flow, the sum of reversing and nonreversing heat flows. The structurally controlled parameters Tg, ΔH, Cp, and ΔCp reveal extrema when the Ge–Se glass system reaches the average coordination number 〈r〉 = 2.67 at 33.3 at.% Ge which corresponds to the stoichiometric composition GeSe2. We also observed extrema in the composition dependence of the above thermal parameters at 20.0 and 40.0 at.% Ge which correspond to stoichiometric compositions GeSe4 and Ge2Se3 with average coordination numbers 2.40 and 2.80, respectively. No such clear local maxima below and above the 33.3 at.% Ge composition could be observed previously in thermal analysis. We compare our MDSC results with previously published works on glass transition in Ge–Se glasses and discuss the results in terms of recent structural models for chalcogenide glasses.

Sign in / Sign up

Export Citation Format

Share Document