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Information for

Tiz Mekonnen

Assistant Professor

Degrees

Tiz Mekonnen

  • PhD: University of Alberta
  • BSc, MSc: Addis Ababa University

Research interests

Renewable polymers, polymer blends, nanomaterial dispersion in polymers, polymer composites, nanocomposites, coatings, packaging, elastomers, 3D printing filaments, electrospinning

There is a great deal of societal and industrial interest in polymeric materials due to their extensive varieties of structure, morphology, and functionality, which make them suitable for an extensive list of applications. These properties can be conferred via rational synthesis, modifications, and a broad range of processing avenues. Our group conducts fundamental and applied research in Polymer Science and Engineering. We utilize Process Engineering and Chemistry tools to create multiphase and multifunctional polymeric materials with a focus on renewable green polymeric materials, and nanocomposites.

Sustainable polymers:

In the last few decades, there is growing concern over the environmental pollution, resource depletion, and health and safety impacts associated with the use and disposal of petroleum-derived polymers. Consequently, there is a global effort to supplement and ultimately replace fossil-derived polymers with smarter, more sustainable, and better performing renewable polymers. We study morphology development and stability of renewable polymer blends as a function of processing conditions, melt history, constituent material properties and functional groups. The use of nature derived macromolecules (and their modifications) in polymers to improve not only the performance but also the cost structure of polymer blends is an integral part of our study. We also investigate the impact of additives in improving the interfacial interaction of blend component phases, and their impact on the biodegradability and/or composability of renewable polymers. Modification of polymers to bring about a balance between biodegradability or compostability, and lifetime of such plastics is often critical.

Polymer nanocomposites

The incorporation of nanoparticles in polymer matrices to prepare nanocomposites can greatly improve the mechanical performance and other functional properties. While the properties of nanocomposites are dictated by how well the nanoparticles are dispersed, these benefits are often hampered by the aggregation of nanoparticles caused by particle – particle interactions. Furthermore, viscosity buildup in polymers that occur upon the addition of small volume fractions of nanoparticles causes processing challenges. We utilize a range of process engineering and chemistry tools to disperse nanoparticles in polymer matrices for multifunctional nanocomposite applications. Also, we conduct chemical modification of polymers and nanomaterials to either introduce useful functional groups for better interaction with each other and/or improve functional performance. Some of the nanocomposite applications we are investigating includes thermoplastic and thermoset structural components, rubbers, packaging sheets and films, coatings, 3D printing filaments, and adhesives.

Selected publications

Journals

  1. Mekonnen, T.,  Misra, M., Mohanty, A. (2016). Fermented Soymeals and their Reactive Blends with poly(butylene adipate-co-terephthalate) in Engineering Biodegradable Cast Films for Sustainable Packaging. 2015. ACS Sustainable Chemistry and Engineering. 4(3): 782-793.
  2. Sun, Q., Mekonnen, T.H. Manjusri Misra, Amar K. Mohanty. (2016.) Novel Biodegradable cast film from carbon dioxide based copolymer and poly (lactic acid). Jouranl of Polymers and the Environment. Jouranl of Polymers and the Environment. 2016, 24(1): 23 – 36.
  3. Mekonnen, T.H., Mussone, P.G., Alemaskin, K.  Wolodko, K. Choi, P., and Bressler, D.C. (2013). Biocomposite materials from Epoxy resin and hydrolyzed biomass: Mechanical, thermal and moisture absorption performances. Journal of Materials Chemistry A, 1, 13186-13196.

  4. Mekonnen, T.H., Mussone, P.G., Khalil, H., and Bressler, D.C. (2013). Progress in plastics and plasticizing modifications: Feature Article. Journal of Materials Chemistry A, 1, 13379-13398.
  5. Mekonnen, T.H., Mussone, P.G., El-thaher, N., Choi, P., and Bressler, D.C. (2013). Thermosetting Epoxy Resin based plastics cured with hydrolyzed proteins. Macromolecular Materials and Engineering.298, 1294–1303.
  6. Mekonnen,T.H., Mussone, P.G., Bressler, D.C. (2016). Valorization of slaughterhouse and rendering industry wastes and co-products for industrial chemicals, materials and energy: review. Critical Reviews in Biotechnology. 36(1): 120-131
  7. El-thaher, N., Mekonnen, T.H., Mussone, P.G., Bressler, D.C., and Choi, P. (2013). Non-isothermal DSC study of epoxy resins cured with hydrolyzed specified risk materials. ACS Industrial & Engineering Chemistry. 52, 8189-8199.
  8. Mekonnen, T.H., Mussone, P.G., Choi, P, Bressler, D.C. (2015). Development of proteinacious plywood adhesive and optimization of its lap shear strength. Macromolecular Materials and Engineering.300 (2), 198 – 209.

Book Chapters

Mekonnen, T., Misra, M., Mohanty, A. Mechanical performance of plant and animal protein based biocomposites and bio-nanocomposites. In: Biocomposites: Design and mechanical performance. Woodhead Publishing Ltd. Elsevier. (2015).

Patents

  1. William Bardosh, Ryan McKenzie, Tizazu Mekonnen, Manoj Nerker, High performance polymer filament for 3D printing. US Patent App. WO2016058097 A1 (2014)
  2. William Bardosh, Ryan McKenzie, Tizazu Mekonnen, Manoj Narkar, Misha Rodriguez. Bioactive biopolymer films and coatings. US Patent App. US2017/0245494.A1 (2017).

Open positions

Graduate student positions are available for talented and motivated students interested in Polymer Science and Engineering. Applicants with strong academic backgrounds in Polymer Science and Engineering, and Chemical Engineering with excellent communication and interpersonal skills are of particular interest. Students with self-supporting funds will be considered with priority. If interested, please contact Prof. Mekonnen with your CV, transcripts, and a summary of your research experience and interests.  

Affiliation: 
University of Waterloo