Rehan Pradhan | ALES Graduate Seminar

Date(s) - 27/05/2020
2:00 pm - 3:00 pm

A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Rehan Pradhan. This seminar is open to the general public to attend.

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Thesis Topic: Solvent free highly efficient Metathesis and development of biobased polyesters from waste and renewable lipids

MSc Dr. Aman Ullah

Seminar Abstract:

Linear economy is a traditional way of making materials, for instance utilization of fossil fuel to develop plastics that finally end-up into landfills and oceans posing threat to the existence of marine life and disrupting natural harmony and co-existence. On the other hand, circular economy is an emerging concept, which induces circular flow of materials that minimizes the reliance on virgin materials and treat waste as the useful feedstock. An attempt was made to adopt the principle of circular economy to develop biobased materials from used waste lipids taken/extracted from used cooking oil and spent hen and compared with canola oil without extensive purification.

This thesis firstly reports the synthesis of polymer precursors from these waste lipidic feedstocks using microwave-assisted solvent-less ethenolysis. The turnover numbers (TONs) of the catalyst were significantly improved through optimization of catalyst/feedstock system. Excellent turnover number values were demonstrated for the ethenolysis of Canola Oil Esters (TONs= 92000), Used-Cooking Oil Esters (TONs= 78080) and Chicken Fat Esters (TONs=21820). Moreover, the synthesis method involved no use of toxic solvents together with the sheer elimination of extensive purification step for substrates and catalysts. Secondly, the ethenolyzed products were separated into non-functionalized olefinic and functionalized olefinic (ester and diester) components, and the isolated diester component was further subjected to condensation polymerization to produce bio-based polyesters. The synthesized product was characterized and investigated using different techniques including Nuclear Magnetic Resonance (NMR), Attenuated Total Reflectance-Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Gas chromatography-Mass Spectroscopy (GC-MS), Gas Chromatography-Flame Ionization Detector (GC-FID), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA) and Universal Testing Machine (UTM). The processed polyester film displayed tensile strength of 2.44 MPa and modulus of elasticity of 137.6 MPa. Efforts were also made to introduce 10-20% of aromatic diol from lignocellulosic biomass to further improve thermomechanical properties. These results indicate potential utilization of waste lipidic resources to substitute conventional petroleum resources.

The present work, based on rapid synthesis and greener approach, could open a new opportunity for sustainable production of bio-based polymer precursors and development of polyesters for utilization in soft packaging and other applications.