Biodegradable and/or compostable biobased powders for additive manufacturing, and methods for the use thereof
The present invention is directed to certain biodegradable and/or compostable biobased particulate compositions for additive manufacturing, such as those including a polyhydroxyalkanoate (PHA) powder, wherein the particulate composition and/or the PHA powder possesses (a) a free bulk density, as determined by ASTM D1895-96, of greater than 0.30 g/mL, and (b) a sinterability region of greater than 15 degrees Celsius. Also, the invention is directed to certain methods of manufacturing such biodegradable and/or compostable biobased particulate compositions useful as powdered build material for additive manufacturing processes. In addition, the present invention is directed to additive manufacturing processes utilizing the biodegradable and/or compostable biobased particulate compositions elsewhere described, along with the articles printed therefrom.
1 . A particulate composition for additive manufacturing comprising or consisting of, a polyhydroxyalkanoate (PHA) powder, wherein the PHA powder comprises or consists of poly-3-hydroxybutyrate (P3HB), poly-4-hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), or copolymers thereof, and wherein the PHA powder possesses
a. a free bulk density, as determined by ASTM D1895-96, of greater than 0.30 g/mL, and
b. a sinterability region of greater than 15 degrees Celsius, wherein the sinterability region is determined by a value of T i,m minus T f,c per ISO 11357-1 (2009).
2 . The particulate composition according to claim 1 , wherein the PHA powder possesses a degree of crystallinity above 30%, wherein the degree of crystallinity is determined via dividing the melting enthalpy (ΔH) determined by a DSC method by a theoretical maximum value of 146 joules per gram (J/g).
3 . The particulate composition according to claim 1 , wherein the sinterability region of the particulate composition and/or the PHA powder is from 15 to 50 degrees Celsius, as determined by ISO 11357-1 (2009).
4 . The particulate composition according to claim 1 , wherein the PHA powder possesses a free bulk density from 0.3-0.65 g/mL.
5 . The particulate composition according to claim 1 , wherein the particulate composition and the PHA powder consists of polyhydroxyalkanoates (PHAs).
6 . The particulate composition according to claim 1 , wherein the particulate composition and/or the PHA powder further comprises or consists of, poly-3-hydroxybutyrate (P3HB), poly-4-hydroxybutyrate (P4HB), or copolymers thereof.
7 . The particulate composition according to claim 1 , wherein the particulate composition and/or the PHA powder comprises or consists of, P3HB.
8 . The particulate composition according to claim 1 , wherein the particulate composition and/or the PHA powder possesses a D50 particle size from 30 to 100 microns.
9 . The particulate composition according to claim 1 , wherein the particulate composition and/or the PHA powder possesses a D90 particle size of 100 microns or less, and a D10 particle size of at least 30 microns.
10 . The particulate composition according to claim 1 , wherein the PHA powder possesses a Tm, onset value of at least 100° C.
11 . The particulate composition according to claim 1 , wherein the PHA powder possesses a Tc, onset value of less than 135° C.
12 . The particulate composition according to claim 1 , wherein the particulate composition further comprises one or more additives, wherein the additives comprise one or more flow aids and are present in an amount by weight, relative to the entire particulate composition, in an amount from 0.5 wt. % to 20 wt. %.
13 . The particulate composition of claim 12 , wherein the one or more flow aids comprise fumed silica and/or precipitated silica.
14 . The particulate composition according to claim 1 , wherein the PHA of the PHA powder has a weight average molecular weight Mw, as determined by gel permeation chromatography against a polymethylmethacrylate standard with hexafluoroisopropanol (HFIP) as an eluent, of 200000 to 1000000 g/mol.
15 . A method of forming an object via an additive manufacturing process comprising the steps of:
(a) providing a layer of a particulate composition for additive manufacturing comprising a PHA powder according to claim 1 ;
(b) optionally, selectively depositing a liquid composition onto the layer of the particulate composition, wherein at least one of the particulate composition or liquid composition comprises a fusing agent;
(c) applying electromagnetic radiation to at least one of:
(i) a specified location on the layer of the particulate composition, or
(ii) a location at which the liquid composition has been selectively deposited onto the particulate composition at step (b);
wherein the particulate composition undergoes melting in at least some of the locations where the electromagnetic radiation and/or the liquid composition has been applied to form a fused section in accordance with computer data corresponding to a portion of a three-dimensional object to be formed; and
(d) repeating steps (a), optionally (b), and (c) a plurality of times to form a fused three-dimensional object.
16 . The method according to claim 15 , wherein the PHA powder possesses a T m , onset value of at least 100° C.
17 . The method according to claim 15 , wherein the particulate composition and/or the PHA powder comprises, or consists of, P3HB, and wherein the PHA powder possesses a free bulk density from 0.3-0.65 g/mL.
18 . The method according to claim 15 , wherein the particulate composition further comprises one or more additives, and wherein the one or more additives comprise one or more flow aids present in an amount by weight, relative to the entire particulate composition, from 0.5 wt. % to 20 wt. %.
19 . The particulate composition of claim 1 , wherein the particulate composition and/or the PHA powder comprises or consists of P3HB, and wherein the PHA powder possesses a free bulk density from 0.3-0.65 g/mL.
20 . The particulate composition according to claim 19 , wherein the particulate composition further comprise one or more additives, and wherein the one or more additives comprise one or more flow aids present in an amount by weight, relative to the entire particulate composition, from 0.5 wt. % to 20 wt. %, and wherein the one or more flow aids comprise fumed silica and/or precipitated silica.
21 . The particulate composition according to claim 1 , wherein the PHA powder possesses a T m , onset value of at least 100° C.
22 . The particulate composition according to claim 1 , wherein the particulate composition further comprises one or more additives, and wherein the one or more additives comprise one or more flow aids present in an amount by weight, relative to the entire particulate composition, from 0.5 wt. % to 20 wt. %, and wherein the one or more flow aids comprise fumed silica and/or precipitated silica.
23 . The particulate composition according to claim 22 , wherein the one or more additives further comprise carbon black particles.