Fused Filament Fabrication of Slow-Crystallizing Polyaryletherketones: Crystallinity and Mechanical Properties Linked to Processing and Post-Treatment Parameters.

Recent advancements in thermoplastics within the polyaryletherketone (PAEK) family have enhanced additive manufacturing (AM) potential in fields like aerospace and defense. Polyetheretherketone (PEEK), the best-studied PAEK, faces limitations in AM due to its fast crystallization, which causes poor inter-filament bonding and warping. This study investigated alternative, slow-crystallizing PAEK polymers: polyetherketoneketone (PEKK-A) and AM-200, a PEEK-based copolymer.

Effect of the chemical surrounding environment on the physical and mechanical properties of aged thermoplastic polymers.

A complete study is presented on the response of thermoplastic and thermoplastic composite materials for bearing cages of bogie trains for rail applications to aging conditions in presence of lubricants. Glass Fiber reinforced Polyamaide 66 (GF PA66) is proposed as commercial material already used in the field while Polyether Ether Ketone (PEEK) is proposed as novel polymeric candidate material due to its chemical stability and high mechanical performance. Accelerated aging tests were performed to analyze the response of these materials to external chemical agents under different conditions.

Effect of Very High Charge Density and Monomer Constitution on the Synthesis and Properties of Cationic Polyelectrolytes.

The free-radical homopolymerization of 1,3-bis(-trimethylammonium)-2-propylmethacrylate dichloride (di-M) and 1,3-bis(-trimethylammonium)-2-propylacrylate dichloride (di-A) in aqueous solution yields cationic polyelectrolytes (PEL) with theoretical/structural charge spacing of only ≈0.12 nm. The high charge density causes condensation of ≈82% of the chloride counterions.