Polyoxymethylene (POM) has found applications as a binder material in Powder Injection Moulding (PIM) due to its ability to depolymerize rapidly under acidic conditions. Such ability represents an advantage during the binder removal step of PIM. However, currently available POM has high viscosity that can complicate the injection moulding process of parts with complex geometry. For this reason it is necessary to investigate methods of lowering the viscosity of POM-based binders, but without affecting their solid mechanical properties (i.e. creep compliance). In this investigation, the addition of a low molecular weight polymer, and the reduction of the average molecular weight of POM were investigated as possible ways of decreasing the viscosity of PIM binders.
COBISS.SI-ID: 13762075
Mechanical material properties of polymers may change significantly when they are exposed to high pressures and/or temperatures. The effect of hydrostatic pressure on shear relaxation modulus of three thermoplastic polyurethanes has been presented in this paper. The results show that chemically identical materials may have significantly different hydrostatic pressure sensitivity. At pressure of 300 MPa, mechanical properties of two materials change only for a factor of 10^5, while for the third material, mechanical properties change 10^9 times.
COBISS.SI-ID: 13741083