Polymeric material and use thereof
A polyaryletherketone PAEK polymeric material and use thereof is disclosed, the polymeric material comprising a homopolymer and/or a copolymer, suitable for use in an additive manufacturing process to make an object. The PAEK polymeric material has a shear viscosity, SV, of at least 145 Pa·s and less than 350 Pa·s, measured using capillary rheometry operating at 400° C. at a shear rate of 1000 s −1 using a circular cross-section tungsten carbide die, 0.5 mm (capillary diameter)×8 mm (capillary length). The PAEK polymeric material has an isothermal crystallinity half life, T 1/2 , of greater than 12 minutes at a temperature of 280° C., measured by Differential Scanning Calorimetry, DSC.
1. A polyaryletherketone PAEK polymeric material comprising a homopolymer and/or a copolymer, suitable for use in an additive manufacturing process to make an object, wherein the PAEK polymeric material has a shear viscosity, SV, of at least 145 Pa·s and less than 350 Pa·s, measured using capillary rheometry operating at 400° C. at a shear rate of 1000 s −1 using a circular cross-section tungsten carbide die, 0.5 mm (capillary diameter)×8 mm (capillary length), and wherein the PAEK polymeric material has an isothermal crystallinity half life, T 1/2 , of greater than 12 minutes at a temperature of 280° C., measured by Differential Scanning Calorimetry, DSC.
2. A PAEK polymeric material according to claim 1 , wherein a co-monomer unit with a phenyl group is incorporated into the PAEK homopolymer.
3. A PAEK polymeric material according to claim 1 , wherein the PAEK polymeric material is a PAEK copolymer.
4. A PAEK polymeric material according to claim 3 , wherein, the PAEK copolymer is a polyetherketoneketone, PEKK.
5. A PAEK polymeric material according to claim 3 , wherein the copolymer comprises repeat units of formula
and a repeat unit of formula
wherein Ph represents a phenylene moiety, wherein at least 95 mol % of the copolymer repeat units are repeat units of formula I and of formula II; wherein the repeat units I and II have a molar ratio I:II from 60:40 to 80:20.
6. A PAEK polymeric material according to claim 3 , wherein the copolymer comprises repeat units of formula
and
repeat units of formula
wherein at least 95 mol % of the copolymer repeat units are repeat units of formula III and of formula IV; wherein the repeat units III and IV have a molar ratio III:IV from 60:40 to 80:20.
7. An automated fibre placement process, AFP, comprising applying sequential layers of fibre to form a composite part, wherein the fibre comprises the PAEK polymeric material of claim 1 , wherein the PAEK polymeric material has a shear viscosity, SV, of at least 200 Pa·s and less than 280 Pa·s, measured using capillary rheometry operating at 400° C. at a shear rate of 1000 s −1 using a circular cross-section tungsten carbide die, 0.5 mm (capillary diameter)×8 mm (capillary length), and wherein the PAEK polymeric material has an isothermal crystallinity half life, T 1/2 , of greater than 20 mins and less than 50 mins at 290° C.
8. A powder bed fusion process comprising forming a component from a polymeric material in a layer by layer process, wherein the polymeric material is the PAEK polymeric material of claim 1 , wherein the PAEK polymeric material has a shear viscosity, SV, of at least 240 Pa·s and less than 350 Pa·s, measured using capillary rheometry operating at 400° C. at a shear rate of 1000 s −1 using a circular cross-section tungsten carbide die, 0.5 mm (capillary diameter)×8 mm (capillary length), and wherein the PAEK polymeric material has an isothermal crystallinity half life, T 1/2 , of greater than 40 mins and less than 80 mins at 290° C.
9. The process according to claim 8 , wherein the PAEK polymeric material is a copolymer and has a repeat unit ratio of at least 62:38 and less than 68:32.
10. The process according to claim 9 , wherein the copolymer has a particle size distribution, PSD, with a D50 range from 45 to 60 μm, a D10>14 μm and a D90<136 μm.
11. A filled filament fusion fabrication process comprising extruding a filament in layers to form a three-dimensional component, wherein the filament comprises the PAEK polymeric material of claim 1 and further comprises a filler, wherein the PAEK homopolymer or copolymer has a shear viscosity, SV, of at least 145 Pa·s and less than 205 Pa·s, measured using capillary rheometry operating at 400° C. at a shear rate of 1000 s −1 using a circular cross-section tungsten carbide die, 0.5 mm (capillary diameter)×8 mm (capillary length), and wherein the PAEK polymeric material has an isothermal crystallinity half life, T 1/2 , of greater than 35 mins and less than 75 mins at 290° C.
12. An unfilled filament fusion fabrication process comprising extruding a filament in layers to form a three-dimensional component, wherein the consists essentially of the PAEK polymeric material of claim 1 , wherein the PAEK homopolymer or copolymer has a shear viscosity, SV, of at least 200 Pa·s and less than 280 Pa·s, measured using capillary rheometry operating at 400° C. at a shear rate of 1000 s −1 using a circular cross-section tungsten carbide die, 0.5 mm (capillary diameter)×8 mm (capillary length), and wherein the PAEK polymeric material has an isothermal crystallinity half life, T 1/2 , of greater than 15 mins and less than 45 mins at 290° C.
13. An additive manufacturing process comprising forming an object from a polymeric material according to claim 1 in a layer by layer process.
14. A PAEK polymeric material according to claim 4 , wherein the PEKK copolymer comprises a combination of PEKK repeat units whereby a proportion of the PEKK repeat units include-1,4-linkages and a proportion of the PEKK repeat units include-1,3-linkages.