Details

Autor(en) / Beteiligte

• Wencke, Yannick L.
• Luinstra, Gerrit A.
• Duchateau, Rob
• Proes, Friedrich
• Imgrund, Philipp
• Evenson, Jonathan S.
• Emmelmann, Claus

Titel

Disentangled UHMWPE@silica powders for potential use in power bed fusion based additive manufacturing

Ist Teil von

• European polymer journal, 2022-01, Vol.163, p.110936, Article 110936

Ort / Verlag

Oxford: Elsevier Ltd

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •First BisIminePyridine iron dichloride catalyst for the formation of dUHMWPE.•Microsilica as support for templating dUHMWPE particles below 200 µm in size.•Thermal sintering of dUHMWPE@silica to materials with UHMWPE properties.•Crystallization of UHMWPE initiated by silica to an unusual structure.•Laser sintering of dUHMWPE@silica shows good flow and consolidation. Disentangled ultrahigh molecular weight polyethylene dUHMWPE (Mw ∼ 2.106Da) particles in a reactor blend with HDPE are catalytically prepared from ethylene, mediated by a new catalyst from N,N'-(2,6-pyridinediyl diethylidyne) bis[2,6-di-3-propenyl-benzenamine] iron dichloride and triethyl aluminum. These particles could be laser sintered, but not automatically processed in an SLS machine. The same catalyst supported on microsilica particles gives access to composite dUHMWPE@silica particle powder with particle sizes below 200 µm. Testing bars prepared by heat pressing have an Emod of 150 MPa, an elongation at break at 450 % and an ultimate strength of 39 ± 11 MPa. A SEM image indicates a silica induced crystallization into pseudo spherulites of 500 µm size. The dUHMWPE@silica composite particles have an fcc flowability value of 3.4 in a ring shear tester, and a low density of 150 kg.m−3. Additivation with nanosilica powder (1 wt%) and carbon black (0.25 wt%) allowed to process the composite in an SLS machine. The printed parts showed severe caking, but also a complete welding of the powder, albeit with voids on account of the low particle density.