Methacrylate-based polymer foams with controllable connectivity, pore shape, pore size and polydispersity.

Polymer foams are becoming increasingly important in industry, especially biodegradable polymer foams are in demand. Depending on the application, polymer foams need to have characteristic properties, which include connectivity and polydispersity. We show how polymer foams with tailor-made structures can be synthesized from water-in-monomer emulsions which were generated via microfluidics. As monomer we used 1,4-butanediol dimethacrylate (1,4-BDDMA). Firstly, we synthesised monodisperse open- and closed-cell poly(1,4-BDDMA) foams with either spherical or hexagonal pore shapes by varying the locus of initiation. Secondly, we were able to control the pore diameters and obtained polymer foams of both connectivities and pore shapes with pore sizes from ∼70 µm up to ∼120 µm by means of one microfluidic chip. Finally, we synthesized poly(1,4-BDDMA) foams with controllable polydispersity. Here, the mean droplet diameter was the same as that of the monodisperse counterparts in order to be able to compare the properties of the resulting polymer foams.