1. Mechanical properties and functional applications of high-sulfur polymers prepared by inverse vulcanization
- Author
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Yan, Peiyao
- Abstract
Elemental sulfur, as a by-product during the hydrodesulfurization process of crude oil, is extensively produced but has incomplete usage despite its main application in the production of sulfuric acid. As a result, there is an abundance of elemental sulfur. There is an urgent need to explore new ways to transform this waste into useful materials. The invention of inverse vulcanization, proposed by Pyun et al. in 2013, provides great opportunities for generating functional polymers directly from elemental sulfur. This synthesis route has gained much attention mentions as its advantages including simple in practice, solvent-free, and high utilization of sulfur. Excitingly, the new category of polymer materials made via inverse vulcanization has been demonstrated to possess various interesting functions, heavy metal capture ability, optical application, self-healing performance, electrochemical properties, antimicrobial properties, etc. However, unsatisfactory mechanical properties have limited the scope for wider applications of these exciting materials. Aiming at improving mechanical properties of inverse vulcanized polymers, the work presented in this thesis mainly has investigated how to improve mechanical properties of inverse vulcanized polymers through various methods. Based on blending crosslinkers in one-step synthesis and introducing strong bonds in two-step synthesis, flexible, strong, stretchable and even tough inverse vulcanized polymers have been formed. Moreover, the relationship between the polymers' structure and their performance have been deeply understood. Furthermore, combined with the enhanced mechanical properties of relevant materials, new applications of those materials, including shape memory, high efficiency thermal recycling and chemical recycling, have been explored. Additionally, in order to explore more efficient way for preparing inverse vulcanized polymers, an alternative route for inverse vulcanization — mechanochemical synthesis, with advantages of mild conditions (room temperature), short reaction time (3 h), high atom economy, less H2S, and broader monomer range, have been proposed. The advantages of mechanochemical synthesis compared with traditional thermal synthesis have been proved in full characterizations. Even more, the specific properties of mechanochemically synthesized inverse vulcanized polymers have been demonstrated and discussed.
- Published
- 2022
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