Toward More Universal Prediction of Polymer Solution Viscosity for Solvent-Based Recycling

Abstract

The viscosity of polymer solutions is important for both polymer synthesis and recycling. Polymerization reactions can become hampered by diffusional limitations once a viscosity threshold is reached, and viscous solutions complicate the cleaning steps during the dissolution−precipitation technique. Available experimental data is limited, which is more severe for green solvents, justifying dedicated viscosity data recording and interpretation. In this work, a systematic study is therefore performed on the viscosity of polystyrene solutions, considering different concentrations, temperatures, and conventional and green solvents. The results show that for the shear rate range of 1−1000 s −1 , the solutions with concentrations between 5 and 39 wt % display mainly Newtonian behavior, which is further confirmed by the applicability of the segment-based Eyring-NRTL and Eyring-mNRF models. Moreover, multivariate data analysis successfully predicts the viscosity of polystyrene solutions under different conditions. This approach will facilitate future data recording for other polymer−solvent combinations while minimizing experimental effort.

RETRACTED: On Improving Water-Based Drilling Mud Swelling Control Using Modified Poly(Vinyl Alcohol)s

“…One cause of low adsorption capacity is that the simultaneous bonding types in base fluids are complementary but somewhat competitive. In dilute solutions where the polymer (mass) concentration lowers 5 wt.%, the polymer chains typically behave as isolated hard spheres, 36 making them highly mobile.…”

Increasing the Dissolution Rate of Polystyrene Waste in Solvent-Based Recycling

“…The entanglement concentration was determined by measuring the viscosity as a function of the polymer concentration. Above the entanglement concentration, the presence of polymer entanglements is dominant, which consequently leads to a drastic increase in viscosity . The viscosities of different polystyrene solutions (1–25 wt %) were measured using an Anton Paar SVM 3001 viscometer at three temperatures: 25, 50, and 75 °C.…”

“…The temperature profile was as follows: a dynamic step from 35 to 250 °C at 15 °C·min –1 , followed by an isothermal step at 250 °C for 15 min, a dynamic step up to 600 °C at 100 °C·min –1 , followed by a dynamic step at 20 °C·min –1 until 700 °C. The mean absolute error associated with TGA measurements is 0.09 wt % and the standard deviation is 0.08 wt % . In most cases, the polymer pellets were not completely dissolved, so part of the clear supernatant was pipetted out for polymer quantification analysis.…”

“…The mean absolute error associated with TGA measurements is 0.09 wt % and the standard deviation is 0.08 wt %. 13 In most cases, the polymer pellets were not completely dissolved, so part of the clear supernatant was pipetted out for polymer quantification analysis. A swollen polymer was obtained for acetone and ethyl formate.…”

“…In the literature, it has been observed that the overlap concentration varies only slightly with temperature . Similarly, the entanglement concentration, which is defined as the transition between the semidilute entangled to a semidilute unentangled region, was also found not to change significantly with temperature. , Most of these studies focus on generating an in-depth understanding of the dissolution process, mainly in a lab environment, but based on a limited set of solvents. The influence of a proper reactor design and impeller type on polymer dissolution kinetics has not been compared to that of lab-scale reactors.…”