Search results for "Isothermal process"
showing 4 items of 114 documents
Normal-phase (temperature gradient) interaction chromatography – A powerful tool for the characterisation of high molecular weight chain-end function…
2015
Abstract We report here, for the first time, quantitative analysis of end-group functionalisation and the extent of end-group modification of polymers with molar mass up to 200,000 g mol −1 , using a combination of isothermal and temperature gradient interaction chromatography. At such high molecular weights, other common analytical techniques such as MALDI-ToF-MS and NMR spectroscopy are simply unable to offer any quantitative insight into the end-group functionality of polymers. Thus, normal phase isothermal interaction chromatography (NP-IIC) has been used to characterise a series of polystyrene samples, with identical molar mass (c. 90,000 g mol −1 ), each carrying a single chain-end fu…
Rheological behaviour, filmability and mechanical properties of biodegradable polymer films
2014
The rheological properties in shear flow and non isothermal elongational flow of two biodegradable polymers, belonging to two different classes of materials, have been measured and compared with those of a film blowing grade high density polyethylene in order to assess the filmability of these polymers. The mechanical properties of isotropic and anisotropic samples have been also reported.
Experimental organic matter maturation at 2kbar: Heat-up effect to low temperatures on vitrinite reflectance
2012
Abstract An experimental study was performed to evaluate the effect of heat-up to various low temperatures on vitrinite reflectance ( VR ) at 2 kbar employing the same previously used heat-up procedures, starting material and apparatus. Heat-up is the isobaric experimental procedure consisting of the increase in temperature of the laboratory vitrinite maturation from room temperature to the desired run temperature T end of heat-up at which the isobaric-isothermal maturation starts. Experiments employed cold-seal pressure vessels with classical heat-up devices and were carried out on wet (water added) xylite of swamp cypress. Confined system maturation experiments were conducted at 2 kbar an…
Differential calorimetric enthalpies of adsorption ofp-xylene andm-xylene on y faujasites at 25°C
1997
The differential enthalpies of adsorption ofp-xylene andm-xylene on NaY, KY and BaY zeolites were measured by isothermal calorimetry coupled with isothermal volumetry at 25‡C. Whatever the zeolite, the enthalpies of adsorption ofp-xylene andm-xylene at low filling were of the same order of magnitude. They did not show significantly the effect of the dipolar moment ofm-xylene. Their absolute values varied in the sequence