Chemistry Student Seminar

Abstract

Perfectly alternating ethylene-CO copolymers (poly(ethylene-alt-CO)) are synthesized by the catalytic copolymerization of ethylene and carbon monoxide. This polymer shows high mechanical properties, abrasion and chemical resistance, as well as the possibility of degradation after a period of usage.1 Because of these promising properties, they have been used in the automotive, pipe, barrier film industries etc. Poly(ethylene-alt-CO) are conventionally processed in melt conditions or using solution spinning methods. These methods possess drawbacks due to the thermal instability of the polymer, its lack of solubility in common organic solvents, as well as the toxic nature of the solvents used.2 Therefore we propose an alternative, environment friendly and energy efficient solid-state processing method for poly(ethylene-alt-CO), which would avoid aforementioned challenges. In this method the nascent polymer is hot-pressed below the melt in the absence of any solvent.3 As this method demands the high molecular weight polymers in order to draw the material maximum to obtain high mechanical properties, we have synthesized poly(ethylene-alt-CO) of Mw up to 2.4*106 g/mol using a reported Pd-based catalytic system under controlled reaction conditions and characterized them using NMR, GPC, FT-IR, WAXD, SEM, TGA, DSC and Viscometry. The initial experiments using this methodology provides promising results with the existing solution spinning processed material reaching a tensile modulus of 8 GPa for a draw ratio of 3.

References

1. Vavasori, A.; Ronchin, L., Polyketones: Synthesis and Applications. In Encyclopedia of Polymer Science and Technology, 2017 pp 1-41.
2. Lommerts, B. J., Structure development in polyketone and polyalcohol fibers. University Library Groningen][Host]: 1994.
3. Rastogi, S.;  Yao, Y.;  Ronca, S.;  Bos, J.; van der Eem, J., Unprecedented High-Modulus High-Strength Tapes and Films of Ultrahigh Molecular Weight Polyethylene via Solvent-Free Route. Macromolecules 2011, 44 (14), 5558-5568.

Bio

Mrudul is currently a second-year Ph.D. student in the research group of Prof. Sanjay Rastogi in the PSE Division, KAUST. He obtained his master's degree in chemistry from the Cochin University of Science and Technology in Kerala, India in 2019. His bachelor's degree in chemistry was earned at Kannur University in Kerala, India in 2017.

As part of his PhD research, he is developing a viable solid state processing method for ultrahigh molecular weight ethylene-CO copolymers as well as new catalytic systems for copolymerization.