0000000000194918
AUTHOR
Thomas Kraska
The effect of pressure on the liquid–liquid phase equilibrium of two polydisperse polyalkylsiloxane blends
The effect of pressure-induced immiscibility in polymer blends is investigated by experimental and theoretical methods. Experimental data of cloud point curves and critical points are obtained by turbidity measurements. The chosen system is a mixture of polydimethylsiloxane and polyhexylmethylsiloxane which is one of the very few polymer blends exhibiting pressure-induced immiscibility. This unusual behaviour is related to a critical temperature minimum of the critical curve and cloud point isopleths at positive pressure in the temperature–pressure diagram. The effect of the chain length on the critical temperature minimum is investigated here based on theoretical models. The effect of diff…
Effect of the phase behaviour of the solvent–antisolvent systems on the gas–antisolvent-crystallisation of paracetamol
Abstract The influence of the phase behaviour of the solvent–antisolvent system on the process conditions for the gas–antisolvent process is investigated. The two fluids are modelled by the Peng–Robinson equation of state while the dissolved solid is described by a Clapeyron-type approach. Based on the correlation of the ternary system, a liquid–liquid immiscibility region has been found which hinders the proper crystallisation of the solute. A thorough investigation of the binary solvent–antisolvent system by the global phase diagram methods yields a criterion for the proper choice of the solvent. The crucial property turns out to be the distance of the solvent–antisolvent system from the …