摘要 |
<p>The invention pertains to foam of polymers, which can be made by a method for making a polymer foam comprising vacuum or gas-filled compartments by a) making a solution of 1 to 20% by weight of a polymer in a solvent; b) adding particles to the a polymer solution; c) solidifying the polymer wherein the particles are contained by heating, cooling, ageing, or coagulating to obtain a polymer foam or matrix comprising the particles, and obtaining from the polymer matrix the polymer foam containing the compartments; and d) optionally washing, drying, and/or heating the polymer foam; wherein in step b) i) the particles are inert hollow particles, wherein the hollow part is the vacuum or gas-filled compartment to give the polymer foam; or ii) the particles are solid particles that are insoluble in the solvent to give the polymer matrix; whereby in step c) the solid particles are removed from the polymer matrix after the heating, cooling, ageing, or coagulating by dissolving the solid particles in a second solvent wherein said solid particles are soluble and the polymer is insoluble, to give the polymer foam; or iii) the particles are expandable particles that upon dissolution in the solvent in step b) and/or during heating in step c) release gas bubbles to give the polymer foam, wherein the polymer is selected from an aramid and a rigid rod polymer.</p> |