Optical Properties of Blown Films of LDPE/HDPE Blends as a Structure Characterization Tool

Polymers are amongst the industrially important materials which are finding widespread applications. The color and optical properties of these materials should be controlled precisely. The polymer films are very important packaging films. The optical properties of these films which are in many cases are composed from different blends closely depend on the blend composition. In this paper the optical properties of the blown films of LDPE/HDPE blends were investigated. It was found that the transmission mode is a more sensitive technique of measurement. The lightness (L*) measured in transmission is different from that measured in reflectance. This was attributed to surface and bulk structure of polymers and blends (crystallinity). The haze measurements divulged existence of a co-continuous structure in blend around 50%LDPE content