摘要 |
<p>PCT No. PCT/FR96/00388 Sec. 371 Date Apr. 29, 1997 Sec. 102(e) Date Apr. 29, 1997 PCT Filed Mar. 13, 1996 PCT Pub. No. WO96/28398 PCT Pub. Date Sep. 19, 1996An alkali aluminosilicate geopolymeric matrix for the production of composite materials with a fiber reinforcement has a composition, after dehydration, expressed as oxides, as follows: yM2O:Al2O3:xSiO2where "x" is 6.5-70, "y" is 0.95-9.50 and M is Na, K or Na+K. The geopolymeric matrix comprises a nanocomposite material with at least two phases, with (a) a first nodular silicious phase composed of nanospheres with diameters of less than 1 micron, preferably less than 500 nm, and (b) a second polymeric phase essentially composed of alkali poly(aluminosilicate) having one or more sialate bridge (-Si-O-Al-O) cross-linking sites of total formula M4Si2AlO10 to M2Si4AlO16, such that, in the alkali poly(aluminosilicate), the ratio of Si(O4) to Al(O4) is >3.5, preferably >5. The geopolymeric matrix has a spectrum of 29Si MASNMR with three resonance regions: -87+/-5 ppm, -98 +/-5 ppm, -107 +/-5 ppm, and prevents the oxidation at high temperatures of the carbon fibre. The resulting composite materials can be used at temperatures of up to 1000 DEG C.</p> |