A paper by Volpe and Pantani, published in Thermochimica Acta, reports on the use of the Linkam Shearing Cell CSS450 to investigate the effect of shear rate on the isothermal crystallisation of poly(lactic acid), ‘PLA’, a biodegradable aliphatic polyester produced from renewable resources. The CSS450 is a temperature-controlled stage that allows the application of a continuous shear flow to a sample while observing its microstructure evolution by hot stage microscopy or spectroscopy.
The researchers coupled the CSS450 with in situ X-ray diffraction measurements at a synchrotron source to study the crystallinity evolution of PLA during continuous shear at different shear rates. They found that increasing the shear rate induced a dramatic decrease of the half crystallisation times; more than one order of magnitude in the analysed range of shear rates. They also applied a model for the description of crystallinity evolution and found that the nucleation rate needed to describe the data is much larger than that measured in a previous work in the same range of shear rates. This study demonstrates the potential of the CSS450 for studying the flow-induced crystallisation of polymers and other materials under realistic processing conditions.
