Thermodynamically-informed approach to the synthesis of 3D printing powders from the mixtures of polyamide 12 with benzyl alcohol

Polyamide 12 is a popular material for manufacturing 3D printing powders, but the existing technologies require harsh processing conditions. This study suggests a new route to obtain powders via the thermally-induced phase separation of polyamide 12 – benzyl alcohol mixtures, which proceeds at ambient pressure without using highly toxic substances. The approach is based on the experimental phase diagram of this system constructed for the first time using an original optical method. The analysis of this diagram allows us to choose the concentration–temperature range suitable for the formation of polymer suspension. It appears that the mean size and dispersity of powders are more sensitive to the rate of cooling than to the composition of the initial polymer–solvent mixture. The parameters of the obtained powder (melting/crystallization temperature, degree of crystallinity, bulk density, and particle size distribution) are close to those of several trademarks, thus making our approach promising for practical realization.