The present invention relates to a process for preparing a porous material, at least comprising the steps of providing a mixture (I) comprising a composition (A) comprising components suitable to form an organic gel and a solvent (B), reacting the components in the composition (A) in the presence of the solvent (B) to form a gel, and drying of the gel obtained in step b), wherein the composition (A) comprises at least one compound (af) comprising phosphorous and at least one functional group which is reactive towards isocyanates. The invention further relates to the porous materials which can be obtained in this way and the use of the porous materials as thermal insulation material and in vacuum insulation panels, in particular in interior or exterior thermal insulation systems as well as in water tank or ice maker insulation systems.

Nanoporous three-dimensional networks of polyurethane particles, e.g., polyurethane aerogels, and methods of preparation are presented herein. Such nanoporous networks may include polyurethane particles made up of linked polyisocyanate and polyol monomers. In some cases, greater than about 95% of the linkages between the polyisocyanate monomers and the polyol monomers are urethane linkages. To prepare such networks, a mixture including polyisocyanate monomers (e.g., diisocyanates, triisocyanates), polyol monomers (diols, triols), and a solvent is provided. The polyisocyanate and polyol monomers may be aliphatic or aromatic. A polyurethane catalyst is added to the mixture causing formation of linkages between the polyisocyanate monomers and the polyol monomers. Phase separation of particles from the reaction medium can be controlled to enable formation of polyurethane networks with desirable nanomorphologies, specific surface area, and mechanical properties. Various properties of such networks of polyurethane particles (e.g., strength, stiffness, flexibility, thermal conductivity) may be tailored depending on which monomers are provided in the reaction.

The present disclosure provides a method for preparing an aerogel or a foam, the method comprising: forming a reaction mixture comprising a cellulose nanofibril gel, a first solvent, and one or more crosslinking agents under conditions sufficient to crosslink the gel; and contacting the crosslinked gel with a second solvent under conditions sufficient to dry the crosslinked gel, thereby forming an aerogel or foam.

Processes for drying gel particles, in particular for producing aerogels, involve providing a suspension containing gel particles and a solvent, introducing the suspension into a column where carbon dioxide flows in countercurrent, and removing dried aerogel particles from the column. The suspension is introduced in the top region of the column and dried aerogel particles are removed in the lower region. Pressure and temperature in the column are set such that the mixture of carbon dioxide and solvent is virtually supercritical or is supercritical. The aerogel particles can be discharged via discharge vessels or continuous decompression. Aerogel particles can be obtained by such a process and the aerogel particles can be used for medical and pharmaceutical applications, as additive or carrier material for additives for foods, as catalyst support, for cosmetic, hygiene, washing and cleaning applications, for production of sensors, for thermal insulation, or as a core material for VIPs.

The present invention provides a gel comprising a physical network formed of polymer chain crystallites interconnected by amorphous chain segments. Functionalization of the chain segments between the crystallites forms a blocky distribution of functionality along the chain whereby the functionalities are concentrated in groups consisting of one or more functionalities, separated by non-functionalized runs of crystallizable segments of the polymer. Removal of the solvent from the gels, without reducing the gel volume, forms an aerogel.

The present invention describes various methods for manufacturing gel composite sheets using segmented fiber or foam reinforcements and gel precursors. Additionally, rigid panels manufactured from the resulting gel composites are also described. The gel composites are relatively flexible enough to be wound and when unwound, can be stretched flat and made into rigid panels using adhesives.

The present disclosure provides an aerogel composition which is durable and easy to handle, which has favorable performance in aqueous environments, and which also has favorable combustion and self-heating properties. Also provided is a method of preparing an aerogel composition which is durable and easy to handle, which has favorable performance in aqueous environments, and which has favorable combustion and self-heating properties. Further provided is a method of improving the hydrophobicity, the liquid water uptake, the heat of combustion, or the onset of thermal decomposition temperature of an aerogel composition.

High-temperature polymer aerogel composites, associated materials, associated methods of manufacture, and applications of polymer aerogel composites including engine covers comprising aerogel materials are generally described.

Systems and methods are provided for aerogel processing and production via vacuum-assisted solvent exchange and ambient pressure drying. In one example, a method includes injecting a solvent at each of a top surface and a base of a saturated aerogel and applying a vacuum-assisted pressure differential across the saturated aerogel to achieve solvent exchange. In some examples, following solvent exchange, the aerogel may be dried in ambient pressure and integrated in a vehicle component. In this way, a rate of solvent exchange may be increased, concomitantly increasing aerogel production efficiency. Further, in some examples, the aerogel may be protected from premature drying during solvent exchange.

Aerogel compositions, methods for preparing the aerogel compositions, articles of manufacture that include or are made from the aerogel compositions are described and uses thereof. The aerogels include a branched polyimide matrix with little to no crosslinked polymers.