Printed macroporous polymers with complex structures and shapes

Abstract

It is our aim to produce macroporous polymers in complex shapes by printing as printing techniques are versatile, give excellent control over the design of the pattern and allow for rapid prototyping. However, inks are required, which can ultimately be cured into macroporous polymers. We, therefore, utilised high and medium internal phase emulsions with a polymerisable continuous phase and an internal droplet phase, which serves as template, as inks in the printing process. Subsequent polymerisation leads to the macroporous polymers. Emulsion templates containing styrene-butadiene-styrene rubber, thiol crosslinker and benzene or toluene as diluting solvent in the continuous phase were syringe printed into cage patterns. Thereby, the wall thickness was controlled by the outer diameter of the needles used, which was varied between 300µm to 750µm. By doing so we were able to print individual cages with sizes between 0.6×0.6mm2 and 2×2mm2 processing well defined and distinct walls. Subsequent UV polymerisation and drying gives rise to a macroporous polymer network within the walls.