Interactions of polymeric components in a POM-based binder system for titanium metal injection moulding feedstocks

Owing to the different characteristics of each of the multiple polymers, obtaining a homogenous metal injection moulding (MIM) feedstock blend is challenging. Therefore, studying interactions between the polymeric components is vital for achieving suitable MIM feedstocks. We report on the effects of different compatibilisers - EGMA and E40 - on the interactions in polyoxymethylene (POM) and polypropylene (PP) blends. We measured contact angles and performed Fourier transform infrared spectroscopy and atomic force microscopy analyses to identify the suitable compatibiliser that yields a feedstock with excellent properties. It was found that the binder system based on EGMA-3 demonstrates the lowest contact angle and best miscibility for the POM/PP blends compared to E40. This enhanced interaction lies in the chemistry of EGMA, having an active site that reduces the interfacial tension between the components of the POM/PP blend. Subsequently, this creates a positive interaction between the polymers and metal powders, ensuring good adhesion within the feedstock.