Absorbent polymeric foam for shoe insoles

1. A process for making a polymeric foam comprising the steps of a) providing a monomeric solution consisting of an acrylic acid, it salt or solutions thereof, water and one or more crosslinkers having more than one polymerizable group per molecule; b) introducing a blowing agent to the monomer solution; c) treating the monomer solution with an ultrasonic treatment in a duration of less than 1 minute, and adding the energy to be transmitted into the monomer solution between 0.01 and 3 kJ/kg monomer solution; d) introducing one or more initiation agents to the monomer solution; e) polymerizing the monomer solution; f) polymerizing the monomer solution into a polymeric foam sheet; and g) cutting or forming the polymeric foam sheet into a shoe sole insert shape, or comminuting the polymeric foam sheet into particles.

2. The process of claim 1 wherein the blowing agent is a carbonate or a bicarbonate based compound or carbon dioxide.

3. The process of claim 1 wherein treating the monomer solution with an ultrasonic treatment comprises introducing energy by an ultrasonic probe or an ultrasonic transducer driven surface.

4. The process of claim 1 wherein the blowing agent is further applied prior to gelation of the monomer solution during polymerization.

5. The process of claim 1 wherein ultrasonic radiation is further applied prior to gelation of the monomer solution during polymerization.

6. The process of claim 1 wherein the ultrasonic treatment produces one or more of the following changes in the polymeric foam when compared to the same process except without ultrasonic treatment: a) a 10% reduction in average pore diameter; b) a 10% reduction in Young's modulus; c) a 10% reduction in vortex time; and d) a 10% increase in the Free Swell Rate (FSR).

7. The process of claim 1 wherein the ultrasonic treatment is in a duration of less than 30 seconds.