A novel processing method for injection-molded polyether-urethane scaffolds. Part 1: Processing

A large-scale scaffold processing method with injection molding has been successfully developed. Water was used as afoaming agent for the new technique. NaCl was used as a porogen to achieve an open-cell structure. Organic solvents, which are common foaming agents for polyurethane, where not used. Toxic remains in the polymer were therefore prevented. Pore size and porosity was adjustable through process parameters. A parameter study showed that an increase in injection pressure, plasticize speed, cylinder, and mold temperature raised the mean pore diameter. The porosity also could be mended by the cylinder and mold temperature, in addition to NaCl concentration. It was possible to produce scaffolds with a porosity of 64 ± 3%, a pore size distribution from 30-450 μm, and a mean pore diameter of 270 ± 90 μm. The interconnective pores were found to lie between 5 and 58 μm.