Polymers are extensively used for tissue repair and replacement in the form of implantable biomedical scaffolds. Examples include surgical meshes, cardiovascular stents, nerve conduits, and bone regeneration scaffolds and fixation devices. Thermal processing is a common denominator in all these applications. Rather than discuss use of the rheometer to study polymer rheology, on which a large body of literature exists, the webinar will focus on the use of capillary rheometer as a tool for optimizing the process parameters with a few grams of polymer before using up hundreds of grams in extruders. Capillary rheometer is indispensable in the evaluation of degradable polymers that have a tight window for processing.
We have taken advantage of the temperature stability of the rheometer to assess the thermal stability of polymers, and drugs and processing aids that are incorporated into polymers. Rheometer can also be used as a small-scale extruder to screen a large number of polymers by extruding ~ 100 μm diameter fibers from which their mechanical and degradation behavior can be ascertained. We have also used rheology to referee the molecular weight determinations of a series of polymers. Some examples of recent successes using the rheometer in our laboratory are the optimization of the conditions for extrusion of fibers from our tyrosine derived polymers, extrusion of ~ 5 mm rods for machining into bone fixation screws, evaluation polymers for 3D printing applications, and for extruding the 1.75 mm diameter filaments for use with 3D printers that use fusion deposition modeling.