Production of porous materials by the expansion of polymer gels

A method of producing a micro- or nano-porous polymer material,

• swelling a polymer starting material using a plasticiser at a predetermined temperature to make the polymer starting material visco-elastic deformable,
• subsequently, contacting the swollen polymer starting material with a foaming agent under a first pressure to obtain a foam, and
• lowering the first pressure to a second pressure to solidify the foam to obtain a micro- or nanoporous material,
• wherein the polymer starting material consists of one or several particularly thermoplastic polymers, preferably a polymer of the group of polymethyl methacrylate (PMMA), polystyrene (PS), polyvinyl chloride (PVC), polylactide (PL), polyethylene (PE), polypropylene (PP), polycarbonate (PC) and cellophane,
• wherein the plasticiser is selected from acetone and other polar aprotic solvents and short chain alkanes,
• wherein the mass ratio of polymer starting material to plasticiser is 10:0.5 to 1:3, preferably 10:2 to 1:1, and
• wherein swelling of the polymer starting material is performed for a time period of 0.1 second to 100 hour, preferably 1 second to 1 hour.