A Novel Simple Approach to Material Parameters from Commonly Accessible Rheometer Data.

Area of Science:

• Polymer Science
• Rheology
• Materials Engineering

Background:

• Shear rheological measurements are standard for polymer viscoelastic properties, impacting extrusion and 3D-printing.
• Characterizing shear-thinning polymers and predicting process influences remain challenging.
• Literature often relies on stress-relaxation data, which is not always available.

Purpose of the Study:

• To present a simple approach for evaluating and benchmarking rheological model systems using accessible frequency sweep data.
• To provide a guideline for determining and evaluating model parameters for viscoelastic materials.
• To establish a basis for understanding and predicting parameters for fabrication techniques like 3D-bioprinting.

Main Methods:

• Utilized frequency sweep data to evaluate various rheological model systems (spring and dashpot models).
• Validated the approach with diverse materials: alginate solutions, thermoplastic polyurethane (TPU), liquid silicone rubber, and a polycaprolactone (PCL) composite.
• Developed a systematic guideline for parameter determination using alginate solutions as an example.

Main Results:

• Demonstrated the suitability of simple spring and dashpot models for describing complex viscoelastic properties of polymer solutions and gels.
• Successfully analyzed and benchmarked different rheological models using frequency sweep data.
• Identified a starting point for correlating model parameters with strut spreading in 3D-bioprinting.

Conclusions:

• The presented approach offers a practical method for evaluating rheological models using readily available frequency sweep data.
• This work enhances the understanding and predictability of material properties crucial for various polymer processing and fabrication techniques.
• The findings facilitate better material selection and process optimization in fields like 3D-bioprinting.