Abstract:
An assembly comprising at least one first pocket (3) which contains a thermally insulating material (5) and in which a first controlled atmosphere prevails, and at least one second pocket (7) which surrounds the first pocket and in which a second controlled atmosphere prevails.The first controlled atmosphere is different from the second one and corresponds to a vacuum of 10 Pa or less. The thermally insulating material (5) preferably has open cells with a diameter greater than or equal to 1 micron.
Abstract:
The present invention relates to a flexible composite organic aerogel (1) comprising: a textile reinforcement (5), an organic aerogel (3) placed within said textile reinforcement (3), said organic aerogel (3) being based on a resin resulting at least in part from polyhydroxybenzene(s) R and formaldehyde(s) F, said organic aerogel (3) being a polymeric organic gel comprising at least one water-soluble cationic polyelectrolyte, or said organic aerogel (3) being a pyrolysate of said gel in the form of a porous carbon monolith comprising the product of the pyrolysis of said at least one water-soluble cationic polyelectrolyte P, said organic aerogel (3) exhibiting a specific thermal conductivity of between 10 and 40 mW·m−1·K−1 at atmospheric pressure.
Abstract:
The present invention relates to a vacuum insulation board (1) comprising: a hermetically closed covering (3) in which the pressure is lower than atmospheric pressure, a core material (5) made of organic aerogel placed inside said covering (3), said organic aerogel being based on a resin resulting at least in part from polyhydroxybenzene(s) R and formaldehyde(s) F, said organic aerogel being a polymeric monolithic organic gel comprising at least one water-soluble cationic polyelectrolyte, or said organic aerogel being a pyrolysate of said gel in the form of a porous carbon monolith comprising the product of the pyrolysis of said at least one water-soluble cationic polyelectrolyte P, said organic aerogel exhibiting a specific thermal conductivity of between 10 and 40 mW·m−1·K−1 at atmospheric pressure.
Abstract:
The invention relates to a process for preparing a gelled, dried composition forming a monolithic aerogel with a heat conductivity of less than or equal to 40 mW·m−1·K−1 and derived from a resin of polyhydroxybenzene(s) and formaldehyde(s), to this aerogel composition and to the use thereof. This process comprises: a) polymerization in an aqueous solvent of said polyhydroxybenzene(s) and formaldehyde(s) in the presence of an acidic or basic catalyst, to obtain a solution based on the resin, b) gelation of the solution obtained in a) to obtain a gel of the resin, and c) drying of the gel to obtain a dried gel. According to the invention, step a) is performed in the presence of a cationic polyelectrolyte dissolved in this solvent, and the process also comprises a step d) of heat treatment under inert gas of the dried gel obtained in step c) at temperatures of between 150° C. and 500° C. to obtain the non-pyrolyzed aerogel whose heat conductivity is substantially unchanged, even after exposure to a humid atmosphere.