Effect of Biofouling on Stability of Polycarbonate in Tropical Seawater

The effect of biofouling on physical, chemical and mechanical changes of Bisphenol A polycarbonate im- mersed at a depth of three meters at two different locations (Port and FSI, Chennai, India) in the Bay of Bengal Sea over a period of six months was the subject of this study. Biofouling in terms of total suspended solids, organic matter and total viable count was higher at Port than at FSI, probably because of higher dissolved oxygen at the former than at the latter site. An increase in glass transition temperature (from 133°C to 147 and 144°C at Port and FSI respectively) was observed in the samples indicating loss of amorphous region and conformational change in the polymer. A two fold decrease in ten- sile strength, a 33% decrease in contact angle and, a reduction in the tertiary methyl and carbonate carbonyl indices were observed. These findings indicate that polycarbonate undergoes a combination of biodeterioration and biodegradation un- der these conditions.