EXPLOITING REFRACTOMETRY TO CALCULATE THE DENSITY OF POLYETHYLENE: THE LORENTZ-LORENZ APPROACH RE-VISITED

摘要

The Lorentz-Lorenz equation is a fundamentally sound theoritical equation that relates refractive index and density. In this study, refractive index measurements were used in combination with the Lorentz-Lorenz equation to determine the density of various polyethylene specimens. Excellent agreement was observed between the specimen density calculated from the Lorentz-Lorenz equation and as measured using a density gradient column. Further, calculating polyethylene density from refractometry experiments using a Metricon Prism Coupling device was noted to be more accurate, more reproducible, simpler and consumes far less time compared to the traditional density gradient column technique.