Measuring degradation related changes in molecular weight and rheology during processing

Understanding and minimizing polycaprolactone degradation during processing using multi-detector GPC and rheology

Abstract

In this application note, a commercially available sample of PCL was extruded alone and in the presence of CO₂­. Multi-detector GPC measurements were made of the virgin sample before and after extrusion, while rotational rheometry was used to study the polymer’s melt viscosity.

Introduction

Polycaprolactone (PCL) is a synthetic polymer that has recently received increasing attention thanks to its biodegradability. Its most common use is in the manufacture of polyurethanes or as a plasticizer for other polymers such as PVC. It is also often used in molding and prototyping thanks to its low melting temperature and is used as a feedstock in some additive manufacturing (3D printing) systems. Finally, it is also used in some drug delivery applications as a control release mechanism, in the same way as polylactic acid (PLA) or polylacticco-glycolic acid (PLGA). A potential advantage over PLA and PLGA is that PCL has a slower degradation rate and therefore may allow for slower drug release.