Fibers differential scanning calorimetry

Die-drawing 143 Die-drawn fibers 144 Differential polarizability tensor 91 Differential scanning calorimetry 63, 165 Diffusion 189... 

Morgan, R. J., Walkup, C. M., Hoheisel, T. H. Differential Scanning Calorimetry Studies of the Cure of Carbon Fiber-Epoxy Composite Prepregs, J. Appl. Polym. Sci., 30, 289 (1985)... 

The complex sorption behavior of the water in amine-epoxy thermosets is discussed and related to depression of the mechanical properties. The hypothesized sorption modes and the corresponding mechanisms of plasticization are discussed on the basis of experimental vapor and liquid sorption tests, differential scanning calorimetry (DSC), thermomechanical analysis (TMA) and dynamic mechanical analysis. In particular, two different types of epoxy materials have been chosen low-performance systems of diglycidyl ether of bisphenol-A (DGEBA) cured with linear amines, and high-performance formulations based on aromatic amine-cured tetraglycidyldiamino diphenylmethane (TGDDM) which are commonly used as matrices for carbon fiber composites. 

For the examinations three different mono- and multifilament PET-yams were used. As seen by the effective temperature two of the fibers (220 dtex multifil and 360 monofil) were heat setted in air at 160°C. The experiments in air and supercritical C02 were carried out in a 400 ml autoclave, the DSC measurements (Differential Scanning Calorimetry) under pressure in a home-made apparatus with an integrated TA-Instruments calorimeter. 

Radhakrishnan and co-workers [6] also studied the freezing of CCI4 in activated carbon fibers (ACF) of uniform nano-scale structures, using Monte Carlo simulation and differential scanning calorimetry (DSC), klicro-porous activated carbon fibers serve as highly attractive adsorbents for simple non-polar molecules. The DSC experiments verified the predictions about the increase in T/. and the molecular results were consistent with equation (1) for pore widths in the mesoporous range they also explained the deviation from the linear behavior in the case of micropores. 

For determination of T by differential scanning calorimetry (DSC), samples were welghed ln the sample container, and the temperature was scanned at a rate of 20 C/mln. For wet determination, the fibers were wet out for 24 hr before testing. 

Figure 3. Differential scanning calorimetry curves for undrawn PET fibers...

The isothermal cure kinetics of a glass fiber-epoxy resin prepreg is investigated using high performance liquid chromatography (HPLC) and differential scanning calorimetry (DSC). The... 

Differential scanning calorimetry (DSC) is widely used as a means of detecting the temperatures of thermotropic transitions, but the technique cannot be used to identify the mesophase. X-ray diffraction measurements on ahgned samples obtained on cooling from the isotropic liquid phase under the influence of a strong magnetic field or by drawing a fiber from the mesophase are able to discriminate between different types of mesophases. 

Information on physical parameters of the molecular structure of polyamide fibers are usually obtained by x-ray diffraction methods, electron and light microscopies, infrared spectroscopy, thermal analyses such as differential thermal analysis, differential scanning calorimetry, and thermomechanical analysis, electron spin resonance, and nuclear magnetic resonance (NMR) spectroscopy. X-ray diffraction provides detailed information on the molecular and fine structures of polyamide fibers. Although the diffraction patterns of polyamide fibers show wide variation, they exhibit usually three distinct regions ... 

Other characterization and identification techniques Polyolefin fibers can be characterized by numerous modem techniques ranging from thermal analysis and various spectroscopy techniques, to electron microscopy and nuclear magnetic resonance (NMR). Differential scanning calorimetry (DSC) is particularly important in determining the melting point of the fiber piece and quickly distinguishing between PE and PP. Polyethylene softens at 130 °C and melts around 140 °C, whereas polypropylene softens at 150 °C and melts around 160 °C. 

The effect of the molecular weight of the PPS and parameters adjusted in the melt spinning process on the properties of the final fibers have been elucidated. Structure-property-relationships were established by the use of tensile testing, differential scanning calorimetry, polarized light optical microscopy, and wide-angle X-ray scattering. 

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