Measuring the rheological properties of polymer melts with on-line rotational rheometry

Mould, Sacha Trevelyan; Barbas, J. M.; Machado, A. V.; Nóbrega, J. M.; Covas, J. A.

doi:10.1016/j.polymertesting.2011.05.002

Cited by 28 publications

(21 citation statements)

References 16 publications

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“…A constant torque plateau, is an indicative of absence of degradation during polymer processing. [14][15][16] Figure 2 shows temperature and torque versus time plots for PCL/bentonite compounds up to 20% w/w clay content. PCL/MMT compounds show constant temperature and torque plateaus for 20 minutes processing time, evidencing absence of molecular weight decaying.…”

Section: -13mentioning

confidence: 99%

Hydrolytic and Thermal Degradation of PCL and PCL/Bentonite Compounds

et al. 2016

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Section: -13mentioning

confidence: 99%

Hydrolytic and Thermal Degradation of PCL and PCL/Bentonite Compounds

et al. 2016

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“…Parallel plate rheometry is a common and reliable method for characterizing the viscosity of molten polymers and it has been used extensively in our laboratories. However, it is an off-line measurement and it does not mimic the shear environment of the extrusion process as faithfully as capillary rheometry [15] . Furthermore, the sample size is small (on the milligram scale) and the long residence time between the heated plates can lead to degradation of the polymer during the test; there is some tendency for the sample to flow out of the aperture at high temperatures over long test durations.…”

Section: Methodsmentioning

confidence: 99%

Viscosity and domain morphology in binary immiscible blends of poly(trimethylene terephthalate) and polyamide6,10

Giancola

Lehman

2012

Journal of Polymer Engineering

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Poly(trimethylene terephthalate) (PTT) and polyamide6,10 (PA6,10) are polymers with significant biobased content that forms an immiscible blend system of high-value engineering materials with enhanced sustainability. Knowledge of the melt viscosity of these thermoplastic materials is critical, when processing blends to achieve optimum morphologies. We measured the viscosities of five extruded blends near the phase inversion composition, over a range of shear rates using both parallel plate and capillary methods. Based on the viscosities of the endmembers, Jordhamo co-continuity should be observed in the 21 -44 volume percent PTT range, depending on the processing shear rate. Extruded blend viscosities were lower than the linear rule of mixtures and the phase inversion composition was identified near 55 volume percent PTT. SEM images showed clear indications of developing cocontinuity in the 55 volume percent PTT. We conclude that the viscosities of immiscible polymer blends in this system do not follow the rule of mixtures, due to slip between immiscible domain interfaces, but that the viscosity and the power law index are useful in locating the phase inversion composition. The empirical Jordhamo relationship, although generally useful in immiscible polymer systems, is not as valuable in this system.

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“…[91] Oscillatory rheometer Barrel On-line Linear viscoelastic behaviour - [91] Rotational rheometer Barrel On-line Morphology development, reaction kinetics, linear viscoelastic behaviour - [92] Barrel On-line Storage and loss modulus of polymer melts - [93] Extensional rheometer Die On-line Melt strength - [95] Slit die…”

Section: Diementioning

confidence: 99%

“…Mould et al [93] monitored the dynamic rheological response of PP in a corotating twin-screw extruder using a new version of the on-line rotational rheometer developed by Covas et al [92] The technique was validated with off-line measurements at room temperature and at high temperatures, and on-line, and the validation step was considered successful. The usefulness of the instrument was first demonstrated with PP, and G′ (storage modulus) and G′ (loss modulus) decreased along the extruder.…”

Section: Rheological Techniquesmentioning

confidence: 99%

Process monitoring and visualization solutions for hot-melt extrusion: a review

Saerens

Vervaet

Remon

et al. 2014

Journal of Pharmacy and Pharmacology

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Objectives Hot-melt extrusion (HME) is applied as a continuous pharmaceutical manufacturing process for the production of a variety of dosage forms and formulations. To ensure the continuity of this process, the quality of the extrudates must be assessed continuously during manufacturing. The objective of this review is to provide an overview and evaluation of the available process analytical techniques which can be applied in hot-melt extrusion. Key Findings Pharmaceutical extruders are equipped with traditional (univariate) process monitoring tools, observing barrel and die temperatures, throughput, screw speed, torque, drive amperage, melt pressure and melt temperature. The relevance of several spectroscopic process analytical techniques for monitoring and control of pharmaceutical HME has been explored recently. Nevertheless, many other sensors visualizing HME and measuring diverse critical product and process parameters with potential use in pharmaceutical extrusion are available, and were thoroughly studied in polymer extrusion. The implementation of process analytical tools in HME serves two purposes: (1) improving process understanding by monitoring and visualizing the material behaviour and (2) monitoring and analysing critical product and process parameters for process control, allowing to maintain a desired process state and guaranteeing the quality of the end product. Summary This review is the first to provide an evaluation of the process analytical tools applied for pharmaceutical HME monitoring and control, and discusses techniques that have been used in polymer extrusion having potential for monitoring and control of pharmaceutical HME.

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Measuring the rheological properties of polymer melts with on-line rotational rheometry

Cited by 28 publications

References 16 publications

Hydrolytic and Thermal Degradation of PCL and PCL/Bentonite Compounds

Hydrolytic and Thermal Degradation of PCL and PCL/Bentonite Compounds

Viscosity and domain morphology in binary immiscible blends of poly(trimethylene terephthalate) and polyamide6,10

Process monitoring and visualization solutions for hot-melt extrusion: a review

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