Title of diploma thesis: Characterization of nanocomposite materials for functional properties
1. Theoretical and professional level of work, the solved problems
The overall quality of this diploma thesis is very good. There is sufficient experiment done to develop PLA based composite films. The composites are made with application of jute nanofibres and various thermal and electrical properties have been evaluated. The thermal properties improved with addition of nanofibres. This was due to the fact that the filler nanofibres help filling the space and help in conducting heat and electricity. They create excellent interface with the PLA. The defined objectives are achieved. Results are compiled in terms of the comparison made between nanocomposites made from tretaed jute fibres and untreated jute fibres. The thesis gives new information about understanding composites made from PLA and jute nanofibres dispersed in it.
2. Work performance, suitability of solution procedure, the formal level
The current study focussed on a novel method for preparation of jute nanofibres by ball milling of short jute fibres to nano jute fibres by using high energy planetary ball milling in wet conditions. This technique has many advantages over other mechanical treatments as it easily provides nanocellulose in bulk quantity at room temperature. The reinforcement potentials of obtained jute nano fibres were then evaluated in improvement of thermal and electrical properties of PLA. This is first attempt to develop such biodegradable composite films by using natural fibre resourses.
3. Accuracy of results, evaluation of findings
In most of the cases, results are accurate. Insome cases more number of testings should have been done to get average of the results and find the variation coefficient. However, looking to the preparation and characterization of sample, which is time consuming, the work is satisfactory .
Jute fibres were successfully milled to nano level i.e. below 500 nm with narrow size distribution after hours of wet milling in deionised water. Themomechanical properties of PLA films loaded with jute nanofibres improved as compared to that of neat PLA films in terms of glass transition temperature, storage modulus, damping factor. However the improvement in properties deteriorated after an optimum limit due to poor dispersion and chances of agglomeration. Thermal stability of the nanocomposite films also improved for every increased loading of jute nanofibres. Electrical resistane is decreased with nano fibre inclusion into PLA films.
doc. Rajesh Mishra,PhD FT, TUL
