PREPARATION AND PROPERTIES OF A NEW SILICON-POLYTRIAZOLE RESIN AND ITS COMPOSITE

Polytriazole (PTA) resins are prepared from azide and alkyne through Huisgen 1,3-dipolar cycloaddition. The PTA resins can be cured at low temperature and possess excellent performances, such as good heat resistance and high mechanical properties. Silicon-containing arylacetylene is a promising monomer for polytriazole resin, as there are lots of arylacetylenes in its backbone which can provide the high crosslinking density and rigid molecular chain. In order to improve the processability, low molecular weight silicon-containing arylacetylene (LPSA) was designed and synthesized from diethynylbenzene and dimethyldichlorosilane by Grignard method. The LPSA was characterized by H-1-NMR and FT-IR. The results show that the degree of polymerization(DP) value of LPSA is ranged from 1.60 to 1.80. A new silicon-polytriazole (Si-PTA) resin was synthesized from 4,4'-diazidomethyl biphenyl(DAMBP) and LPSA via 1,3-dipolar cycloaddition. The Si-PTA resin was characterized by H-1-NMR, FT-IR, differential scanning calorimetry (DSC). The results show that the resin could be cured at 80 degrees C. The dynamic thermomechanical analysis(DMA) results show that the glass transition temperature(T-g) of the cured Si-PTA resin is 310 degrees C after curing 80 degrees C for 12 h, 150 degrees C for 2 h, 180 degrees C for 2 h, 210 degrees C for 2 h, and 250 degrees C for 2 h. Thermogravimetric analysis (TGA) results show that the thermal decomposition temperature(T-d5, temperature at 5% weight loss) under N-2 and air could reached 342 degrees C and 340 degrees C, respectively. Unidirectional T700 carbon fiber reinforced Si -PTA composite (Si-PTA/T700) was prepared through compression molding. The structures and properties of the composite were characterized by mechanical property tests, DMA, etc. The results show that the Si -PTA composite exhibited good mechanical and thermal properties, the flexural strength is 1678 MPa at room temperature and 1095 Mpa at 200 degrees C.