Topic
Differential scanning calorimetry
About: Differential scanning calorimetry is a research topic. Over the lifetime, 50315 publications have been published within this topic receiving 1152335 citations. The topic is also known as: DSC.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, two newly synthesized polybenzoxazines were successfully cured with carbon fiber to obtain composites with 60 vol% fiber, and the effect of cure temperature on the T g of the composites was investigated.
Abstract: To develop high-performance composites with high temperature resistance, two newly synthesized polybenzoxazines were successfully cured with carbon fiber to obtain composites with 60 vol% fiber. Results from differential scanning calorimetry studies were used to modify the benzoxazine monomers to improve processability in terms of melting point and solubility. The density and void content of these composites were measured. Dynamic mechanical tests were performed to determine the glass transition temperature (T g ) and the activation enthalpy of the glass transition process for these two composites. The effect of cure temperature on the T g of the composites was investigated. Thermal characteristics were studied by means of dynamic mechanical analysis in terms of isothermal aging, decomposition temperature from thermogravimetric analysis, and storage moduli change at high temperatures. Mechanical evaluations of these composites were conducted by flexural and interlaminar shear tests. The mechanical and thermal properties of these two composites exceed bismaleimide composites and compete with polyimide composites, while exhibiting easier processability than polyimides.
171 citations
TL;DR: In this paper, a model-free kinetic (MFK) analysis was performed on the DSC heating rate results and the results showed the possibility of a multi-step thermal decomposition of CL-20 and the enthalpies of reaction and onset temperatures were determined for various heating rates.
171 citations
TL;DR: In this paper, high molecular weight polyetheresters (PEE) containing thermally curable benzoxazine units in the main chain have been synthesized, which preserve shape and toughness after thermal curing between 140 and 220 °C.
Abstract: High molecular weight polyetheresters (PEE) containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diol functional monomer is synthesized through the Mannich reaction of 4,4′-isopropylidenediphenol (bisphenol A), formaldehyde, and 2-(2-aminoethoxy)ethanol. Polycondensation of the resulting benzoxazine dietherdiol with adipoyl chloride and terephthaloyl dichloride in the presence of triethyl amine yields the corresponding PEE with the molecular weights of 34.000 Da. The structures of the precursor diol monomer and the resulting PEEs are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy (1H-NMR) analysis. Curing behavior of both the monomer and polymers has also been studied by differential scanning calorimetry (DSC). Flexible free standing transparent films of the PEEs are obtained by solvent casting from dichloromethane solution on Teflon plates. The films preserve shape and, to some extent, toughness after thermal curing between 140 and 220 °C. Thermal properties of the cured polymers are also investigated by thermogravimetric analysis (TGA). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 414–420, 2008
170 citations
TL;DR: In this paper, a stirring ball mill was used to mechanically activate cassava starch and the resulting amorphous particles were seen to agglomerate during the process of mechanical activation.
170 citations
TL;DR: The data show that when a high oxidant concentration is used, polyaniline is mostly formed at the surface of the Nafion membrane with a higher proportion of oligomers, blocking the pathway to ion transport and thus reducing the transport of Zn2+ as well as the Transport of H+.
Abstract: Nafion membranes were modified by chemical polymerization of aniline using ammonium peroxodisulfate as the oxidant. The Nafion-polyaniline composite membranes were extensively characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), infrared (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and ion-exchange capacity measurements. The transport properties were also evaluated by conductivity and electrodialysis measurements. The data show that when a high oxidant concentration (1 M (NH4)2S2O8) is used, polyaniline is mostly formed at the surface of the Nafion membrane with a higher proportion of oligomers. On the contrary, when 0.1 M oxidant is used, polyaniline is mostly formed inside the ionic domains of Nafion, blocking the pathway to ion transport and thus reducing the transport of Zn2+ as well as the transport of H+. These data were also compared to the data obtained with poly(styrene sulfonate)-PANI composite membranes.
170 citations