Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485175
Title: Biodegradation of Coated and Uncoated Regenerated Cellulose Films
Author: Farajollahi, Sanaz
ISNI:       0000 0001 3457 2283
Awarding Body: University of Leeds
Current Institution: University of Leeds
Date of Award: 2007
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Abstract:
Packaging films are an inevitable aspect of the modem societies. This is especially so in the food containment industry. These days most of the packaging films that are available in the market are made from polyolefmic materials. Although these materials perform superior package functions, they are riot biodegradable. This is a cause of concern for the environment. Unlike polyolefinic packaging, packaging made from regenerated cellulose films are biodegradable because of their cellulosic source. However, modification of these films to deliver suitable packaging functions could compromise the biodegradability of these films. The application of an impemieable thermoplastic coating, . of colorants and the use ofplasticizers are among the modifications that interfer~with the biodegradability of the regenerated cellulose packaging. The influence of several factors on the biodegradation behaviour of different types of coated and uncoated cellophane films was studied in this research. Two general approaches were undertaken for this study. Firstly, the influence of a specific colour reducing bacterium, Shewanella strain JI8 143, on coated regenerated cellulose films, in the presence and in the absence of colorant materials, was investigated. Secondly, microorgamsms that are capable of degrading various coated and uncoated regenerated cellulose films were enriched from landfill soil inocula. Degradation behaviour of each film was then studied using the cultivated culture. Several. analytical techniques were used to establish the changes that were induced into the treated regenerated cellulose. films. Techniques such as UV spectrophotometry, FTIR spectrop40tometry, contact angle measurement, SEM analysis, differential scanning calorimetry and gas chromatography were used. A number of molecular biology approaches such as the polymerase chain reaction (peR) procedure and restriction enzyme digestion were undertaken to an~lyse the community profile ofthe enriched culture. Evidence is given to show that the nitrocellulose coating underwent denitrification when treated with Shewqnella 118 143 culture in the presence of azo dye. However, poly(vinylidene chloride) coating incubated with Shewanella 118 143 culture did not undergo any significant chemical changes either in the· presence or in the absence of azo dye. The enrichment study, based on the biodegradation of various regenerated cellulose films, indicated that the biodegradation rate of cellulosic films was greater under anaerobic conditions than under aerobic conditions. The enrichment provides a number of c·ultures that are capable of utilising cellophane films as a carbon source, under anaerobic conditions. Activities of both bacteria and methanogenic archaea were observed in all of the enriched cultures. Profiling bacterial community ofthe enriched cultures gave general information concerning the way these enriched cultures are related.
Supervisor: Not available Sponsor: Not available
Qualification Name: University of Leeds, 2007 Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.485175  DOI: Not available
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