A Study On The Modification Of The Linear Polybenzimidazole By New Nano-Materials

Polymer organic/inorganic nanocomposites consist of polymers and nano-size particles, which combine the advantages of nano-materials and polymers. The nanocomposites not only have the advantages of inorganic nano-materials (such as high rigidity, high thermal stability, special electromagnetic and light properties and so on), but also have the advantages of polymer materials (such as high flexibility, scalability and processing properties). All of these advantages make polymer/inorganic nanocomposites be one of the hottest researches in recent years.In this thesis, a polybenzimidazole is selected as the polymer matrix, and the octaphenyl polyhedral oligomeric silsesquioxane (POSS) and Nanodiamonds (NDs) as the nano-materials in our research. The polybenzimidazole/inorganic nanocomposites have been prepared by in situ polymerization. The microstructure and macroscopic properties of the nanocomposites were studied here. The summary of this work are as follows.1. We synthesized POSS/OPBI nanocomposites through in situ polymerization of 4, 4'-dicarboxydiphenyl ether (DCDPE), 3, 3'-diaminobenzidine (DABz) and octaphenyl POSS in polyphosphoric acid (PPA) and phosphorus pentoxide system. The Weight contents of POSS are controlled at 1%, 2%, and 5% respectively. The POSS compound sites to be well dispersed in polymer matrix and part of them acted as cross linking points in the composites. The nanocomposites showed excellent macroeconomic performance. We also prepared the POSS/OPBI blending composites for comparison. In this paper we studied the structure, dispersion, mechanical and thermal properties of the two nanocomposites in detail. We found that 2 wt% POSS content in nanocomposites that synthesized by in situ polymerization is sufficient to improve the mechanical properties of the polymer matrix.2. We synthesized NDs/OPBI nanocomposites through in situ polymerization of 4, 4'-dicarboxydiphenyl ether (DCDPE), 3, 3'-diaminobenzidine (DABz) and octaphenyl POSS in polyphosphoric acid (PPA) and phosphorus pentoxide system. The Weight contents of POSS are controlled at 1%, 2%, and 5% respectively. The NDs Compound sites to be well dispersed in polymer matrix and OPBI chains were grafted to NDs successfully by F_C reaction. The nanocomposites showed excellent macroeconomic performance. We also prepared NDs/OPBI blending composites for comparison. In this paper we studied the structure, dispersion, mechanical and thermal properties of the two nanocomposites in detail. We found that the properties of the nanocomposites were improved with little toughness sacrificed.