Abstract:
This disclosure provides a solvent-borne system for forming an n-acyl urea coating on a substrate. In one embodiment, the solvent-borne system comprises a polycarbodiimide-polyurethane hybrid. The solvent-borne system also comprises an acid functional polymer and an organic solvent, and comprises less than or equal to 10 weight percent of water based on a total weight of said solvent-borne system. The solvent-borne system also comprises less than about 100 parts by weight of toluene diisocyanate per one million parts by weight of the solvent-borne system.
Abstract:
A curable sealant composition includes a polysulfide having an —SH group, a compound having at least one carbon-carbon double bond, and an alkylborane amine catalyst. A cured sealant is formed from the curable sealant composition, wherein the cured sealant includes the polymerization product of the polysulfide and the compound having the at least one carbon-carbon double bond reacted in the presence of the alkylborane amine catalyst. Furthermore, a curable sealant system includes a first component including the polysulfide and the alkylborane amine catalyst and a second component including the compound having the at least one carbon-carbon double bond. Moreover, an article includes a substrate and the cured sealant disposed on the substrate. The curable sealant composition is formed using a method including the steps of providing and combining the polysulfide, the alkylborane amine catalyst, and the compound having the at least one carbon-carbon double bond, to form the curable composition.
Abstract:
A proppant includes a particle present in an amount of from 90 to 99.5 percent by weight and a polymeric coating disposed about the particle and present in an amount of from 0.5 to 10 percent by weight, based on the total weight of the proppant. The polymeric coating is formed from a curable composition comprising an isocyanate, an acrylate, and a polyol. A method of forming the proppant includes the steps of combining the isocyanate, the acrylate, and the polyol to form the curable composition, coating the particle with the curable composition, and curing the curable composition to form the polymeric coating.
Abstract:
A composition for forming a polyiso-urea includes a capped polycarbodiimide and a polyol. The capped polycarbodiimide comprises the reaction product of a diisocyanate and a monoisocyanate in the presence of an oxygen scavenger and a carbodiimidization catalyst and in the absence of solvent, has 0.25 wt. % or less of free isocyanate groups, and is a liquid at 25° C. A polyiso-urea comprises the reaction product of the capped polycarbodiimide and the polyol.
Abstract:
A proppant includes a particle and a hybrid coating disposed about the particle. The particle is present in an amount of from about 90 to about 99.5 percent by weight based on the total weight of the proppant and the hybrid coating is present in an amount of from about 0.5 to about 10 percent by weight based on the total weight of the proppant. The hybrid coating comprises the reaction product of an isocyanate component and an alkali metal silicate solution including water and an alkali metal silicate. A method of forming the proppant includes the steps of providing the particle, the isocyanate composition, and the alkali metal silicate solution. The method also includes the steps of combining the isocyanate composition and the alkali metal silicate solution to react and form the hybrid coating and coating the particle with the hybrid coating to form the proppant.
Abstract:
Modified isocyanate compositions having improved properties are provided. The compositions may be formed from the reaction of a isocyanate component, which is a compound terminated with at least one isocyanate group, and an organic acid derivative having the formula (RO)n(M)(E)(EH)3-n, wherein M is nitrogen, phosphorus, arsenic, antimony, or bismuth, n is 1 or 2, each E is independently oxygen, sulfur, selenium, or tellurium, each R is independently hydrogen, an alkyl group, a cyclic aryl group, an acyclic aryl group, a halogen-substituted alkyl group, a halogen-substituted cyclic aryl group or a halogen-substituted acyclic aryl group and wherein the ratio of the weight of the isocyanate component to the combined weight of the organic acid derivative and the isocyanate component is from 0.7 to 0.95. The compositions can be utilized in a variety of applications and are adapted to prolonged storage and transportation. Methods of preparing such compositions are also provided.
Abstract:
A continuous process forms a unitary mat on a line having at least two conveyors spaced from each other. The process includes combining the isocyanate, an isocyanate catalyst, and a plurality of lignocellulosic particles to form a mixture and a self-polymerization product of the isocyanate in-situ in the mixture. The process also includes forming the unitary mat from the mixture on a first conveyer and transferring the unitary mat from the first conveyor to a second conveyor across a predetermined distance while maintaining structural integrity of the unitary mat. The lignocellulosic particles have a moisture content of 0.5 to 30 weight percent of water. Moreover, the continuous process is free of a step of adding water to the isocyanate, the isocyanate catalyst, the lignocellulosic particles, and/or the unitary mat.
Abstract:
A composition for forming a polyiso-urea includes a capped polycarbodiimide and a polyol. The capped polycarbodiimide comprises the reaction product of a diisocyanate and a monoisocyanate in the presence of an oxygen scavenger and a carbodiimidization catalyst and in the absence of solvent, has 0.25 wt. % or less of free isocyanate groups, and is a liquid at 25° C. A polyiso-urea comprises the reaction product of the capped polycarbodiimide and the polyol.
Abstract:
A proppant comprises a particle and a polycarbodiimide coating disposed on the particle. The polycarbodiimide coating comprises the reaction product of an isocyanate reacted in the presence of a phospholene oxide catalyst. A method of forming the proppant comprises the steps of providing the particle, providing the isocyanate, providing the phospholene oxide catalyst, reacting the isocyanate in the presence of the phospholene oxide catalyst to form the polycarbodiimide coating, and coating the particle with the polycarbodiimide coating.
Abstract:
A process of preparing a post-modified polycarbodiimide, the process includes combining a diisocyanate, a moisture scavenger, a monoisocyanate, and a catalyst in a reaction vessel; and heating the reaction vessel to a temperature and a time sufficient to form a capped polycarbodiimide wherein the capped polycarbodiimide has 0.25 wt % or less of free isocyanate groups; and the combining and heating are conducted in the absence of a solvent.