Rheology of Polymeric Systems

Carreau, Pierre J.; Kee, Daniel C.R. De; Chhabra, R.P.

doi:10.3139/9781569907238

Cited by 7 publications

(3 citation statements)

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“…The Bird-Carreau-Yasuda model was chosen for fitting, as the model best described the measured data (Equation ( 2)). [28] With 𝜂 0 as the zero shear viscosity, ̇𝛾 as the share rate, n as the Power Law index, accounting for shear thinning, 𝜆 as a time constant and the parameter a controlling the curvature.…”

Section: Rheologymentioning

confidence: 99%

Toughening of Bio‐Based PA 6.19 by Copolymerization with PA 6.6 – Synthesis and Production of Melt‐Spun Monofilaments and Knitted Fabrics

Rist

Löcken

Ortega

et al. 2023

Macromol. Rapid Commun.

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This work reports on the synthesis of statistical copolymers of bio‐based PA 6.19 and PA 6.6 together with the production of melt‐spun monofilaments for the production of sustainable textile fibers. The plant oil‐based 1.19‐nonadecanedioic acid is synthesized from bio‐derived oleic acid via isomerizing methoxycarbonylation. The homopolymer PA 6.19 with a carbon‐based bio‐content of 72% shows a good elongation at break of 166%, but lower tensile strength than commercial PA 6 (43 MPa versus 82 MPa). Addition of adipic acid to form statistical PA 6.6/6.19 copolymers improves toughness while maintaining the high elongation at break. Two PA 6.6/6.19 copolymers with a carbon‐based bio‐content of 26% and 33% are successfully synthesized and exhibited comparable toughness (94 ± 6 MPa and 92 ± 2 MPa) to the commercial PA 6 (92 ± 15 MPa). The bio‐based copolymers also exhibit a much lower water uptake than PA 6 and PA 6.6, resulting in a higher dimensional stability. Melt spinning of the oleic acid‐based polyamides is successfully carried out to produce monofilaments with sufficient properties for further processing in a knitting process, demonstrating the capabilities of the bio‐based PA 6.6/6.19 copolymers for use in the textile industry.

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Section: Rheologymentioning

confidence: 99%

Toughening of Bio‐Based PA 6.19 by Copolymerization with PA 6.6 – Synthesis and Production of Melt‐Spun Monofilaments and Knitted Fabrics

Rist

Löcken

Ortega

et al. 2023

Macromol. Rapid Commun.

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“…The melt viscosity at the die (η die ) was calculated with the Hagen-Poiseuille Law [26], using the correction of Weissenberg-Rabinowitsch [27] in its simplified form valid for fluids that follow the Ostwald-de Waele power-law model, in order to account for the shear-thinning behavior of the polymer melts.…”

Section: Melt Temperature Predictionmentioning

confidence: 99%

Predicting Residence Time and Melt Temperature in Pharmaceutical Hot Melt Extrusion

2023

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Hot-melt extrusion is increasingly applied in the pharmaceutical area as a continuous processing technology, used to design custom products by co-processing drugs together with functional excipients. In this context, the residence time and processing temperature during extrusion are critical process parameters for ensuring the highest product qualities, particularly of thermosensitive materials. Within this study, a novel strategy is proposed to predict the residence time distribution and melt temperature during pharmaceutical hot-melt extrusion processes based on experimental data. To do this, an autogenic extrusion mode without external heating and cooling was applied to process three polymers (Plasdone S-630, Soluplus and Eudragit EPO) at different specific feed loads, which were set by the screw speed and the throughput. The residence time distributions were modeled based on a two-compartment approach that couples the behavior of a pipe and a stirred tank. The throughput showed a substantial effect on the residence time, whereas the influence of the screw speed was minor. On the other hand, the melt temperatures during extrusion were mainly affected by the screw speed compared to the influence of the throughput. Finally, the compilation of model parameters for the residence time and the melt temperature within design spaces serve as the basis for an optimized prediction of pharmaceutical hot-melt extrusion processes.

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“…Many polymer systems can be adequately described by simple viscoelastic Maxwell or Zener models, 30 but more complex models such as the Generalized Maxwell and the parallel rheological framework can in theory provide a more accurate recreation of physical phenomena like relaxation and viscous flow. 31,32 These viscoelastic models can be implemented into finite element simulations and their results can be compared with experimental stress and relaxation data to determine how closely the viscoelastic models predict the behavior of bilayers strips as well as more complex bilayer architectures. Currently, there is no universal standard for testing the curvature of a viscoelastic bilayer.…”

Section: Introductionmentioning

confidence: 99%

Elastic/viscoelastic polymer bilayers: a model-based approach to stretch-responsive constructs

Mills,

Chou,

Baierl

et al. 2024

Soft Matter

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Rheology of Polymeric Systems

Cited by 7 publications

References 0 publications

Toughening of Bio‐Based PA 6.19 by Copolymerization with PA 6.6 – Synthesis and Production of Melt‐Spun Monofilaments and Knitted Fabrics

Toughening of Bio‐Based PA 6.19 by Copolymerization with PA 6.6 – Synthesis and Production of Melt‐Spun Monofilaments and Knitted Fabrics

Predicting Residence Time and Melt Temperature in Pharmaceutical Hot Melt Extrusion

Elastic/viscoelastic polymer bilayers: a model-based approach to stretch-responsive constructs

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