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 E40on 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.

When polyoxymethylene (POM)—a common polymer used in metal injection moulding feedstock—is exposed to heat and oxygen during compounding, it can be easily decomposed, releasing undesired gaseous formaldehyde products. In order to reduce the formaldehyde emission from POM, amine treatment was performed. The effectiveness of propylamine at different concentrations and its role as a formaldehyde scavenger was studied via the UV–vis Spectrophotometry, Fourier Transform Infra-red, Thermogravimetric Analysis, Scanning Electron Microscopy, and melt flow index. The results proved that a simple amine, such as propylamine, is a promising candidate for scavenging formaldehyde in POM. It is also demonstrated that the best concentration of propylamine is 2 wt.% (POM-PA2) with a minimum formaldehyde emission of 1.44 mg/L. Further, when used in formulating metal injection moulding feedstock (MIM), the POM-PA2 reveals good rheological properties and high green strength. These advantages make the modified polyoxymethylene (POM-PA2) a promising binder system for MIM feedstock.