Crystallinity and crystalline phase orientation of poly(1,4-cis-isoprene) fromHevea brasiliensisandTaraxacum kok-saghyz
| Autor: | Mario Maggio, Sara Musto, Marco Di Mauro, Maurizio Galimberti, Gaetano Guerra, Vincenzina Barbera |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Polymers and Plastics Nucleation 02 engineering and technology 010402 general chemistry 01 natural sciences law.invention chemistry.chemical_compound Crystallinity Natural rubber law Phase (matter) Polymer chemistry Taraxacum kok-saghyz Crystallization Isoprene biology 021001 nanoscience & nanotechnology biology.organism_classification 0104 chemical sciences Crystallography chemistry visual_art Saturated fatty acid visual_art.visual_art_medium 0210 nano-technology |
| Zdroj: | Polymers for Advanced Technologies. 27:1082-1090 |
| ISSN: | 1042-7147 |
| Popis: | Crystallization is studied for poly(isoprene-1,4-cis) from Hevea brasiliensis (natural rubber [NR]) and from taraxacum kok-saghyz, mainly by collecting wide-angle X-ray diffraction patterns after processing and stretching. Although rubber samples before stretching are generally fully amorphous, crystallization can be induced in NR samples by processing at room temperature under moderate pressure. This phenomenon is possibly associated with nucleation by saturated fatty acid components. For rubber samples being fully amorphous in the undeformed state, strain-induced crystallization occurs only at high strain ratios (α > 4), leading to high degrees of crystalline phase orientation (fc > 0.9 for α = 5). Rubber samples presenting some crystallinity already in the unstretched state, on the contrary, reach much lower degrees of axial orientation, even for high strain ratios (fc |
| Databáze: | OpenAIRE |
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