Fire-Retardant Polyamide 11 Nanocomposites/Elastomer Blends for Selective Laser Sintering: Further Studies

摘要

Additive manufacturing had previously been used solely for prototyping and visualization purposes, but in recent years, this technique has been shifted to the idea of producing end-use parts. This has already been done successfully in some areas via selective laser sintering (SLS). Unfortunately, current polymeric materials for processing via SLS do not meet the requirements of the majority of commercial applications. Hence, the objective of this research is to develop a multifunctional polyamide 11 (PA11) polymer with enhanced thermal, mechanical, and flammability properties for SLS through the use of nanotechnology. Previous studies indicate that although fire-retardant modified PA11 shows effective reduction in heat release capacity, it suffers significant loss in elongation at break and tensile strength when compared to neat PA11, which limits its applications. Studies on rubber toughening of polyamide demonstrate that the elongation at break can be improved by manipulating rubber content and particle size. For this research, six different formulations of PA11 with intumescent fire-retardant (FR) additives toughened by a maleic anhydride modified elastomer were processed by twin-screw extrusion. Tensile bars were made via injection mold to test the mechanical, thermal, and flammability properties of PA11 for all six formulations. The formulations that demonstrated the best results were then compounded with nanoclay via twin-screw extrusion. Mechanical, thermal, and flammability tests were carried out on the tensile bars made via injection mold for these formulations. The formulations that demonstrated the best results will be used to fabricate test specimens via SLS for material properties characterization.