Effect of Polyamide 66 on the Mechanical and Thermal Properties of Post-Industrial Waste Polyamide 6

Abstract Post-industrial waste (PIW) polyamide 6 is successfully used in lieu of commercial virgin polyamide 6, in several automotive applications. The presence of polyamide 66 in the final formulation may affect the mechanical and thermal properties of the PIW polyamide 6 materials. Using unreinforced polyamide 6 from PIW and commercial sources, it was found that the addition of polyamide 66 (below 10 wt.%) lowered the crystallization rate and crystallinity level of all polyamide 6 materials. The thermal and mechanical properties of glass fiber (GF) reinforced PIW polyamide 6 compounds with and without polyamide 66 were also studied. Differential scanning calorimetry (DSC) showed that reinforced materials without polyamide 66 had a higher level of crystallinity. Furthermore, dynamic mechanical analysis (DMA) showed that reinforced compounds without polyamide 66 also had a faster storage modulus buildup immediately after injection molding. Reinforced PIW polyamide 6 compounds without polyamide 66 also exhibited higher tensile and higher vibration weld strengths as well as a thicker heat affected zone (HAZ) than those with polyamide 66, leading to the conclusion that polyamide 66 had a detrimental effect on crystallinity level and consequently on the mechanical properties of GF-reinforced PIW polyamide 6 materials. Keywords: CrystallizationPolyamide 6Polyamide 66Post-industrial wasteRecyclingVibration welding ACKNOWLEDGMENTS The authors would like to express their gratitude to Mr. Jim Vanderveen and Dr. Bobbye Baylis at MAHLE for useful discussions and providing the resins. A special word of thanks to Mr. John Perreault and Mr. Clarence McEwen in the Department of Chemistry and Chemical Engineering in the Royal Military College of Canada, for their assistance during the injection-molding process. Notes Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/lpte.