Zeena, Hamza P; Dr.Thomas, Kurian(Cochin University of Science And Technology, October , 2012)
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Abstract:
Biodegradation is the chemical degradation of materials brought
about by the action of naturally occurring microorganisms. Biodegradation
is a relatively rapid process under suitable conditions of moisture, temperature
and oxygen availability. The logic behind blending biopolymers such as starch
with inert polymers like polyethylene is that if the biopolymer component is
present in sufficient amount, and if it is removed by microorganisms in the
waste disposal environment, then the base inert plastic should slowly
degrade and disappear.
The present work focuses on the preparation of biodegradable and
photodegradable blends based on low density polyethylene incorporating small
quantities of ionomers as compatibilizers.
The thesis consists of eight chapters. The first chapter presents an
introduction to the present research work and literature survey. The details of
the materials used and the experimental procedures undertaken for the study
are described in the second chapter. Preparation and characterization of low
density polyethylene (LDPE)-biopolymer (starch/dextrin) blends are
described in the third chapter. The result of investigations on the effect of
polyethylene-co-methacrylic acid ionomers on the compatibility of LDPE
and starch are reported in chapter 4. Chapter 5 has been divided into two
parts. The first part deals with the effect of metal oxides on the
photodegradation of LDPE. The second part describes the function of
metal stearates on the photodegradation of LDPE. The results of the
investigations on the role of various metal oxides as pro-oxidants on the
degradation of ionomer compatibilized LDPE-starch blends are reported in
chapter 6. Chapter 7 deals with the results of investigations on the role of
various metal stearates as pro-oxidants on the degradation of ionomer
compatibilized LDPE-starch blends. The conclusion of the investigations is
presented in the last chapter of the thesis.
Description:
Department of Polymer Science and Rubber Technology,
Cochin University of Science and Technology
Gisha Elizabeth, Luckachan; Dr. C K S Pillai(Regional Research Laboratory (CSIR), May , 2006)
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Abstract:
Biodegradable polymers have opened an emerging area of great interest
because they are the ultimate solution for the disposal problems of synthetic
polymers used for short time applications in the environmental and biomedical
field. The biodegradable polymers available until recently have a number of
limitations in terms of strength and dimensional stability. Most of them have
processing problems and are also very expensive. Recent developments in
biodegradable polymers show that monomers and polymers obtained from
renewable resources are important owing to their inherent biodegradability,
biocompatibility and easy availability. The present study is, therefore, mostly
concemed with the utilization of renewable resources by effecting chemical
modification/copolymerization on existing synthetic polymers/natural polymers
for introducing better biodegradability and material properties.The thesis describes multiple approaches in the design of new
biodegradable polymers: (1) Chemical modification of an existing nonbiodegradable
polymer, polyethylene, by anchoring monosaccharides after
functionalization to introduce biodegradability. (2) Copolymerization of an
existing biodegradable polymer, polylactide, with suitable monomers and/or
polymers to tailor their properties to suit the emerging requirements such as
(2a) graft copolymerization of lactide onto chitosan to get controlled solvation
and biodegradability and (2b) copolymerization of polylactide with cycloaliphatic amide segments to improve upon the thermal properties and
processability.