Photodegradation Effect of Structure of Linear Low Density Polyethylene – Starch – Clay Nanocomposite Film

Abstract

Degradable plastic is a topic that continues to be discussed, especially for disposable applications. Blending starch with commercial plastics such as Linear Low Density Polyethylene was the alternative that continues to be developed. The degradation mechanism of biopolymer may occur as microorganisms and also through the mechanism of exposure to sunlight or Ultra Violet light. In this work, degradation test on Linier Low Density Polyethylene-starch-clay nanocomposite film was conducted with a Xenon Arc. Nanocomposite samples were prepared from masterbatch clay and 10% wt and 20% wt of starch. Pure Linear Low Density Polyethylene was used as a control parameter. On day 7th, 20% wt starch sample was already brittle and 10%wt starch was brittle on day 14th. In the 3th day of Xenon Arc aging, starch granulates already disappeared on the surface of sample and the degraded starch leave a hole on the surface of Linear Low Density Polyethylene matrix. The hole dimension became larger with time increasing of Xenon Arc aging. Thermo Gravimetric Analysis result showed decreasing onset temperature degradation for the starch. The oxidation and degradation of starch was occurred during the aging. Meanwhile onset temperature degradation of Linear Low Density Polyethylene in the nanocomposite sample was increased might be this occurred due to the formation of crosslink on Linear Low Density Polyethylene before degraded. Image of 10% wt and 20% wt starch observed using Atomic Force Microscope also showed that the degradation occurs on starch. It was proved by the image after 14 days aging become the same as the image of Linear Low Density Polyethylene used as a control that showed the lamella of Linier Low Density Polyethylene.