Biodegradation of montmorillonite filled oxo‐biodegradable polyethylene

Abstract

Oxo-biodegradation of polyethylene has been well studied with different pro-oxidants and it has been shown that pro-oxidants have limited role in the oxidation of polyethylene and do not have any role in microbial growth. However, in few recent studies, montmorillonite clay has been reported to promote the growth of microbes by keeping the pH of the environment at levels conducive to growth. In an attempt to improve the overall oxo-biodegradation of polyethylene, montmorillonite nanoclay has been used in this study along with a prooxidant. Film samples of oxo-biodegradable polyethylene (OPE) and oxo-biodegradable polyethylene nanocomposite (OPENac) were subjected to abiotic oxidation followed by microbial degradation using microorganism Pseudomonas aeruginosa. The progress of degradation was followed by monitoring the chemical changes of the samples using high-temperature gel permeation chromatography (GPC) and infrared spectroscopy (FTIR). The growth of bacteria on the surface of the polymer was monitored using environmental scanning electron microscopy.GPC data and FTIR results have shown that the abiotic oxidation of polyethylene is influenced significantly by the pro-oxidant but not by nanoclay. But, the changes in molecular weight distribution and FTIR spectra for the biodegraded samples indicate that the growth rate of P. aeruginosa on OPENac is significantly greater than that on OPE. It indicates that nanoclay, by providing a favourable environment, helps in the growth of the microorganism and its utilisation of the polymer surface and the bulk of the polymer volume.

Occurrence, Degradation, and Effect of Polymer-Based Materials in the Environment

“…First, are those that have a biodegradable ingredient, such as starch, which is added to the polymer matrix to link short strands of the polymer chain together (Drimal et al 2007;Reddy et al 2003). Second, nano clay composites are used to provide a favorable environment for growing microorganisms that can utilize the polymer matrix as a food source; montmorillonite clay has been reported to promote microbial growth by stabilizing pH in the polymer matrix (Reddy et al 2009). Third are those produced from the bacterial fermentation of sugars and lipids that comprise a class of polymers that include polyhydroxyalkanoates (PHA), polylactides (PLA), aliphatic polyesters, polysaccharides, copolymers, and/or blends of the above.…”

TiO2-kaolin-PE composite film: A study based on photocatalytic degradation and biodegradation

“…The photo-degradation reaction was carried out in an air at around 25 C in an open lamp-housing box (120 3 40 3 40 cm 3 ). The films were irradiated under UV light with a 30 W ultraviolet lamp (Jiangsu Juguang).…”

Biodegradability Characterization of Polymer Nanocomposites

“…[52] , fi lm samples of oxobiodegradable polyethylene ( OPE ) and oxobiodegradable polyethylene nanocomposite ( OPENac ) were subjected to abiotic oxidation followed by microbial degradation using microorganism Pseudomonas aeruginosa . The progress of degradation was followed by monitoring the chemical changes of the samples using high -temperature GPC and FTIR.…”

“…Reddy et al . [52] proposed that the nanoclay provided a favorable environment to microorganisms, helping them to proliferate [52] …”