Content area
Full Text
J Polym Environ (2009) 17:170180 DOI 10.1007/s10924-009-0135-x
ORIGINAL PAPER
Fouling and Degradation of Polycarbonate in Seawater: Field and Lab Studies
Trishul Artham Mukesh Doble
Published online: 26 August 2009 Springer Science+Business Media, LLC 2009
Abstract Biofouling and ensuing microbial mediated degradation of Bisphenol A polycarbonate was studied by immersing the samples in sea water of Bay of Bengal (Chennai, India) for 3 months and also under controlled laboratory conditions with marine mixed microbial consortia for 12 months. A 9% weight loss in the sample was observed after 1 year of incubation under in vitro laboratory conditions. A 5% reduction in number average molecular weight and an additional oligomer with a molecular weight of 930 was observed in the same sample. Contact angle decreased by 11% indicating an increase in the surface hydrophilicity. The specic heat decreased by 44% and glass transition temperature decreased by 3 C with respect to the control indicating chain scission. Formation of new hydroxyl groups and cleavage of carbonate bonds in polycarbonate suggested biodegradation. About 9 lg mL-1 of Bisphenol A, a monomer of polycarbonate, as well as its oxidized products were detected in the supernatant. The nature of degradation in eld and in vitro was different. It was predominantly oxidation in the former and hydrolysis in the later environment. A strain exhibiting hydrolase activity was isolated at the end of the 12 months from the in vitro mixed consortia and was identied, based on biochemical and 16S rDNA tests, as Pseudomonas sp. BP2 (GenBank accession no. EU920674).
Keywords Pseudomonas sp. BP2 Biodegradation
GPC FTIR Polycarbonate Field studies
Introduction
Poly (bisphenol-A-carbonate) (PC) nds extensive applications, ranging from windshields on boats to biomonitoring units in water analysis due to its durability, optical clarity, toughness and its ability to be blended with other polymers. About 2.7 million tons of PC is produced annually [1]. The steep rise in its production in the recent past and its durability has lead to increasing problems of littering and challenges in waste management. When this polymer is exposed to seawater there is a possibility of Bisphenol A (BPA), one of the monomers, leaching out [2]. BPA has been classied as an endocrine disruptor due to its estrogenic action and has an acute toxicity in the range of...