Extraction of spear grass (imperata cylindrica) as pro-oxidant in polymer blends

Abstract

Packaging material such as plastic bags is one of the main factors that contribute to the environmental pollution due to slow degradation. The usage of metal oxide as pro-oxidant has proved to accelerate the degradation of these materials, but excessive use of this prooxidant will be harmful to the human body. Therefore, in this research, spear grass is investigated to be used as natural based pro-oxidant that can increase the degradation rate of the polymers. In order to do that, spear grass is extracted by using pressurized hot water extraction (PHWE) to obtain the metal element such as zinc (Zn) and ferum (Fe) that can make spear grass act as pro-oxidant. PHWE is using water as a solvent which is highly favourable due to non-toxicity and non-flammable characteristics that make it easy to handle. Box-Behnken design was used to optimize the temperature, extraction time, and sample-to-solvent ratio to get the maximum amount of Zn and Fe concentration from the extracted spear grass. Based on this study, the leaf of spear grass contributed the highest amount of Zn and Fe concentration. The highest amount of Zn and Fe concentration achieved at 150 ◦C, 20 minutes, and 3 g of sample to 45 ml of water. Addition of extracted spear grass at optimum conditions has proven to accelerate the degradability of polymers based on higher percentages of weight loss during the soil burial test. This concluded that, the spear grass can act as pro-oxidant to accelerate the degradation of polymers.