Tough Semicrystalline Thiol–Ene Photopolymers Incorporating Spiroacetal Alkenes
| Autor: | Eric Sun, Ken Gall, Dalton G. Sycks, David L. Safranski, Neel B. Reddy |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Toughness Materials science Polymers and Plastics Alkene Organic Chemistry 02 engineering and technology Polymer 010402 general chemistry 021001 nanoscience & nanotechnology Microstructure 01 natural sciences 0104 chemical sciences Inorganic Chemistry Crystallinity Photopolymer chemistry Polymer chemistry Materials Chemistry 0210 nano-technology Glass transition Ene reaction |
| Zdroj: | Macromolecules. 50:4281-4291 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/acs.macromol.7b00628 |
| Popis: | We report a tough, semicrystalline, ternary thiol–ene polymer system containing linear dithiols, cross-linking trithiols, and spiroacetal alkene units in the main chain backbone that is synthesized by “click” ultraviolet photopolymerization in a one-step, solvent-free process. We varied the cross-link density to tune crystallinity and microstructure; in turn, thermomechanical properties such as yield strength, glass transition temperature, failure strain, and stress–strain behavior could be modified and controlled. Thiol–enes containing 7.5 and 10 thiol mol % cross-linker resulted in networks that balanced crystallinity, elasticity, and cross-linking to maximize toughness. These materials demonstrate how the presence of spiro units throughout a polymer’s backbone creates semicrystalline networks of substantial toughness from traditionally weak chemistries such as thiol–enes. This system can be synthesized in a neat, one-step photopolymerization process; as such, it illustrates the power of spirochemistry ... |
| Databáze: | OpenAIRE |
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