USE OF MICRO-RAMAN SPECTROSCOPY FOR THE QUANTITATIVE-DETERMINATION OFPOLYETHYLENE DENSITY USING PARTIAL LEAST-SQUARES CALIBRATION

A series of polyethylene samples were analysed using a micro Raman sys tem. The data were analysed using a commercial partial least-squares p ackage and correlated with the polymer density, A correlation coeffici ent of up to 0.98 was obtained, depending on the spectral region used, A standard error of prediction of 2.15 kg m(-3) was obtained and the densities of 'blind' samples were predicted with good accuracy.