Effect of reactive extrusion process parameters on thermal, mechanical, and physical properties of recycled polyamide-6: comparison of two novel chain extenders

Two chain extenders having different molecular structures; an alternating copolymer of ethylene and maleic anhydride (EMA) and a novel chain extender, dimeric 2,4-toluene diisocyanate (DTDI), both at two different concentrations (0.5 and 1 wt%), were melt compounded with recycled polyamide 6 (rPA6) using a twin-screw extruder. In order to investigate the effect of temperature profile and residence time on the chain extension behaviors of these chain extenders three different temperature profiles and four different throughput rates were selected for the melt compounding. Effects of the parameters were observed through differential scanning calorimetry (DSC) measurements, relative viscosity measurements, and tensile and impact tests. Temperature and time dependent improvements of the chain extended products with EMA and DTDI showed different tendencies. While chain extension of rPA6 with EMA became more effective with the optimization of the barrel temperature profile, chain extension with DTDI was not affected by temperature changes. By adjusting the temperature profile 9.1% higher viscosity, 1.3 times higher elongation at break and 10.6% higher impact strength were obtained for the chain extension reaction of rPA6 with EMA. Longer residence time promoted the chain extension reaction of rPA6 with EMA. On the other hand, chain extension of rPA6 with DTDI was not significantly affected by residence time

Selective Laser Sintering Manufacturing and Characterization of Lightweight PA 12 Polymer Composites with Different Hollow Microsphere Additives

The use of additives in polyamide polymeric SLS built frameworks further reinforces the goal of developing lightweight components, which serves as the basis for the current investigation. In this paper, different amounts of hollow glass microspheres (HGMs) were added to polyamide 12 (PA 12), and their sintered components were compared for their physical and mechanical properties, including tensile and 3-point bending tests. In terms of density reduction, the PA 12-20HGM composite structure achieved the highest reduction figure of 20.8 %. According to specific strength and modulus calculations, PA 12-20HGS60 and PA 12-20HGM composite structures provided the highest mechanical test results

Effects of Copper Fillers on Mechanical and Electrical Properties of Selective Laser Sintered PA 12-Cu Composites

Selective Laser Sintering (SLS) is a widely used additive manufacturing (AM) technique for creating 3D geometries by adding materials in layers. Although neat polymer is mainly used in powder forms for production, organic or inorganic fillers can be added to produce polymer composites by SLS method. In this study, Polyamide 12 (PA 12) matrix composite parts filled with two different copper particles, dendritic and spherical shaped, were produced, and their mechanical, structural and electrical properties were investigated. The present study outlined that by increasing incident energy densities during sample fabrication, changes in mechanical and electrical characteristics were examined. The findings were analysed in terms of filler type and energy input, which were discovered to have a slight change in the bending behaviour of SLS components. Furthermore, the impact strength was shown to increase constantly with increasing energy density. Furthermore, whereas the electrical conductivity of spherical Cufilled parts rose considerably, no significant change was seen in dendritic-shaped Cu-filled parts

Effects of copper fillers on mechanical and electrical properties of selective laser sintered PA 12-Cu composites

Selective Laser Sintering (SLS) is a widely used additive manufacturing (AM) technique for creating 3D geometries by adding materials in layers. Although neat polymer is mainly used in powder forms for production, organic or inorganic fillers can be added to produce polymer composites by SLS method. In this study, Polyamide 12 (PA 12) matrix composite parts filled with two different copper particles, dendritic and spherical shaped, were produced, and their mechanical, structural and electrical properties were investigated. The present study outlined that by increasing incident energy densities during sample fabrication, changes in mechanical and electrical characteristics were examined. The findings were analysed in terms of filler type and energy input, which were discovered to have a slight change in the bending behaviour of SLS components. Furthermore, the impact strength was shown to increase constantly with increasing energy density. Furthermore, whereas the electrical conductivity of spherical Cu-filled parts rose considerably, no significant change was seen in dendritic-shaped Cu-filled parts