Polymer-propellant compositions forming foamed structures.

摘要

Compositions and a process for manufacture are provided for synthetic polymer-propellant systems that form cohesive foamed structures from which aqueous solutions can be expressed, where the useful temperature range over which these structures form is broadened by using a propellant mixture consisting predominantly of a propellant that is a poor solvent for the polymer and has a vapor pressure in the range of 10-35 psig at 20 DEG C in combination with a small amount of a propellant that is a good solvent for the polymer; and where these coherent foamed structures can be formed even with aqueous solutions containing 0 to about 30% alcohol, provided that insoluble fine-particle solids that do not pack and become difficult to redisperse are included in the composition.