| Autor: |
Kholkhoev BC; Baikal Institute of Nature Management, Siberian Branch of the Russian Academy of Sciences, 670047 Ulan-Ude, Russia., Matveev ZA; Baikal Institute of Nature Management, Siberian Branch of the Russian Academy of Sciences, 670047 Ulan-Ude, Russia., Bardakova KN; Research Center 'Crystallography and Photonics', Russian Academy of Sciences, 108840 Moscow, Russia.; Institute for Regenerative Medicine, Sechenov University, 119991 Moscow, Russia., Timashev PS; Research Center 'Crystallography and Photonics', Russian Academy of Sciences, 108840 Moscow, Russia.; Institute for Regenerative Medicine, Sechenov University, 119991 Moscow, Russia.; Semenov Institute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia.; Chemical Department, Lomonosov Moscow State University, 119991 Moscow, Russia., Burdukovskii VF; Baikal Institute of Nature Management, Siberian Branch of the Russian Academy of Sciences, 670047 Ulan-Ude, Russia. |
| Abstrakt: |
A series of aliphatic polybenzimidazoles (PBIs) with methylene groups of varying length were synthesized by the high-temperature polycondensation of 3,3'-diaminobenzidine (DAB) and the corresponding aliphatic dicarboxylic acid in Eaton's reagent. The influence of the length of the methylene chain on PBIs' properties was investigated by solution viscometry, thermogravimetric analysis, mechanical testing and dynamic mechanical analysis. All PBIs exhibited high mechanical strength (up to 129.3 ± 7.1 MPa), glass transition temperature (≥200 °C) and thermal decomposition temperature (≥460 °C). Moreover, all of the synthesized aliphatic PBIs possess a shape-memory effect, which is a result of the presence of soft aliphatic segments and rigid bis -benzimidazole groups in the macromolecules, as well as strong intermolecular hydrogen bonds that serve as non-covalent crosslinks. Among the studied polymers, the PBI based on DAB and dodecanedioic acid has high adequate mechanical and thermal properties and demonstrates the highest shape-fixity ratio and shape-recovery ratio of 99.6% and 95.6%, respectively. Because of these properties, aliphatic PBIs have great potential to be used as high-temperature materials for application in different high-tech fields, including the aerospace industry and structural component industries. |
