Synthesis and curing study of a new phenolphthalein-formaldehyde resin
Abstract The preparation of a new methylolic resin derived from condensation of phenolphthalein and formaldehyde is described. The resin was characterised by spectroscopic, elemental analysis and moisture evolution analysis (MEA) techniques. The thermosetting (curing) characteristics of the resin were investigated by MEA and differential scanning calorimetry. Several thermosetting parameters were determined, i.e. rate of setting, degree of setting and the activation energy of the setting reactions, and the determined values for the latter parameter were found to be 58.2 and 18.29 kJ mol −1 which were related to the dehydration and dehydroformylation reactions respectively. The degree of setting varies linearly with temperature.
This paper presents an inferential property prediction scheme for a high pressure polyethylene autoclave reactor. The development of a dynamic model of the process is described. It was derived from a consideration of the reaction mechanism and uses reaction temperatures, pressure and gas composition to predict the degree of polymerisation of the polymer. The values of certain key parameters in the model were derived from steady state data from the ICI Alkathenc plant at Botany Site. The model was shown to predict the degree of polymerisation during grade transition with an appropriate accuracy although it benefited from an on-line adaption scheme.