Abstract: The present disclosure provides a plurality of glass bubbles having an average true density of up to about 0.55 grams per cubic centimeter and a size distribution including a median size in a range from about 15 micrometers to 40 micrometers. A hydrostatic pressure at which ten percent by volume of the plurality of glass bubbles collapses is at least about 100 megapascals. In some embodiments, the plurality of glass bubbles is a graded fraction preparable by classifying a second plurality of glass bubbles, wherein the second plurality of glass bubbles has a higher percentage of glass bubbles with a size of up to ten micrometers than the first plurality of glass bubbles. Composites including the plurality of glass bubbles are also disclosed.

Abstract: The present disclosure provides a plurality of glass bubbles having an average true density of up to about 0.55 grams per cubic centimeter and a size distribution including a median size in a range from about 15 micrometers to 40 micrometers. A hydrostatic pressure at which ten percent by volume of the plurality of glass bubbles collapses is at least about 100 megapascals. In some embodiments, the plurality of glass bubbles is a graded fraction preparable by classifying a second plurality of glass bubbles, wherein the second plurality of glass bubbles has a higher percentage of glass bubbles with a size of up to ten micrometers than the first plurality of glass bubbles. Composites including the plurality of glass bubbles are also disclosed.

Abstract: The present disclosure provides a plurality of glass bubbles having an average true density of up to about 0.55 grams per cubic centimeter and a size distribution including a median size in a range from about 15 micrometers to 40 micrometers. A hydrostatic pressure at which ten percent by volume of the plurality of glass bubbles collapses is at least about 100 megapascals. In some embodiments, the plurality of glass bubbles is a graded fraction preparable by classifying a second plurality of glass bubbles, wherein the second plurality of glass bubbles has a higher percentage of glass bubbles with a size of up to ten micrometers than the first plurality of glass bubbles. Composites including the plurality of glass bubbles are also disclosed.

Abstract: A buffing composition includes an emulsion having an aqueous liquid phase and an oily liquid phase; a solubilized zirconium carboxylate; and fine abrasive particles having a Mohs hardness of at least 4. The fine abrasive particles have a particle size distribution having at least one mode with a particle size of at least 5 micrometers. A method of finishing a surface of a material using the buffing composition is also disclosed.

Abstract: A buffing composition includes an emulsion having an aqueous liquid phase and an oily liquid phase; a solubilized zirconium carboxylate; and fine abrasive particles having a Mohs hardness of at least 4. The fine abrasive particles have a particle size distribution having at least one mode with a particle size of at least 5 micrometers. A method of finishing a surface of a material using the buffing composition is also disclosed.

Abstract: A firestop apparatus that allows substantial longitudinal and radial movement of a pipe that extends through an opening in a partition. The firestop includes a thermal insulator assembly that surround the pipe, is positioned to slidably engage with a surface of the partition, and is sized to substantially cover the opening even when the pipe is moved to the edge of the opening. A first seal is interposed between the insulator and the pipe to permit longitudinal movement of the pipe through the insulator. A second seal is interposed between the insulator and the partition to permit radial movement of the pipe and insulator relative to the opening. A securing structure allows radial movement of the insulator relative to the opening while maintaining engagement of the insulator against the side of the partition.