Characterizing films of polyethylene blends: An application of colorimetric parameters measurements

This study reports an application of instrumental color measurement for quantifying and comparing the optical properties of high density polyethylene HDPE and low density polyethylene LDPE blend films and the effect of blending ratio and miscibility on these properties. The technique of spectrophotometry in transmission and reflectance modes can be used as a versatile tool to evaluate the colorimetric parameters of polymers. The optical properties of the films indicated likeliness of affecting color spectrum by incorporating low-density PE LDPE into high-density PE HDPE. This is the principal reason for changing colorimetric parameters of the films. CIE colorimetric values in CIELab and CIELCho color scales and associated parameter Color Intensity CI showed that they are practical for comparing the blend films. The most change in the values versus composition was pertained to films of HDPE-rich blends which were verified miscible using thermal analysis. In this paper it was observed that the used measurement technique, through quantitative parameters provided by it, would be useful to reveal the difference in behavior of the HDPE/LDPE blends at miscible compositions from immiscible ones.