Crosslinked polymeric composition and its use in additive manufacturing
A crosslinked polymeric composition comprising a base polymer containing unconjugated carbon-carbon double bonds of the formula —CR a ═CR b —, wherein a portion of said unconjugated carbon-carbon double bonds in said base polymer are interconnected by a crosslinker (L) as shown in the following structure: wherein: R a and R b are independently selected from hydrogen atom and hydrocarbon groups, wherein R a and R b may optionally interconnect to form a ring; x represents the molar percentage of segments that are linked with the linker L throughout the crosslinked polymeric composition; L is a crosslinker having the formula: —S—R 1 -L a -R 2 -L b -R 1 —S—; R 1 and R 2 are independently selected from hydrocarbon linking groups containing at least one carbon atom; L a and L b independently represent dynamic reversible crosslinking groups; and Z a and Z b independently represent remaining portions of the base polymer.
1 . A crosslinked polymeric composition comprising a base polymer containing unconjugated carbon-carbon double bonds of the formula —CR a ═CR b —, wherein a portion of said unconjugated carbon-carbon double bonds in said base polymer are interconnected by a crosslinker (L) as shown in the following structure:
wherein:
R a and R b are independently selected from hydrogen atom and hydrocarbon groups containing at least one carbon atom, wherein, in the case where R a and R b are both hydrocarbon groups, said hydrocarbon groups optionally interconnect to form a ring;
2× represents the molar percentage of segments that are linked with the linker L throughout the crosslinked polymeric composition;
L is a crosslinker having the formula: —S—R 1 -L a -R2-L b -R 1 —S—;
R 1 and R 2 are independently selected from hydrocarbon linking groups containing at least one carbon atom;
L a and L b independently represent dynamic reversible crosslinking groups independently selected from the group consisting of imine (—C═N—) bonds, disulfide bonds, carboxy ester bonds, urea bonds, silyl ether bonds, vinylogous urethane, and urethane bonds; and
Z a and Z b independently represent remaining portions of the base polymer.
2 . The crosslinked polymeric composition of claim 1 , wherein the base polymer is selected from the group consisting of acrylonitrile-butadiene-styrene, styrene-butadiene-styrene, styrene-butadiene, acrylonitrile-butadiene, polybutadiene, polyisoprene, polynorbornene, and poly(aryl glycidyl ether) polymers.
3 . The crosslinked polymeric composition of claim 1 , wherein the base polymer contains a polybutadiene block.
4 . The crosslinked polymeric composition of claim 3 , wherein the crosslinked polymer composition has the following structure:
wherein:
R a and R b are independently selected from hydrogen atom and hydrocarbon groups containing at least one carbon atom, wherein, in the case where R a and R b are both hydrocarbon groups, said hydrocarbon groups optionally interconnect to form a ring:
L is a crosslinker having the formula: —S—R 1 -L a -R 2 -L b -R 1 —S—;
R 1 and R 2 are independently selected from hydrocarbon linking groups containing at least one carbon atom;
L a and L b independently represent dynamic reversible crosslinking groups independently selected from the group consisting of imine (—C═N—) bonds, disulfide bonds, carboxy ester bonds, urea bonds, silyl ether bonds, vinylogous urethane, and urethane bonds;
2b corresponds to the molar percentage of butadiene units in the polymer and is an integer of at least 1;
A and B represent other polymerized units; and
subscripts a and c independently represent an integer of at least 1.
5 . The crosslinked polymeric composition of claim 3 , wherein the base polymer is selected from the group consisting of acrylonitrile-butadiene-styrene, styrene-butadiene, acrylonitrile-butadiene, and polybutadiene.
6 . A method of producing a crosslinked polymeric composition comprising:
(i) providing a base polymer containing unconjugated carbon-carbon double bonds of the formula —CR a ═CR b —, wherein R a and R b are independently selected from hydrogen atom and hydrocarbon groups containing at least one carbon atom, wherein, in the case where R a and R b are both hydrocarbon groups, said hydrocarbon groups optionally interconnect to form a ring;
(ii) reacting a portion of said unconjugated carbon-carbon double bonds with thiol-containing molecules of the formula HS—R 1 —X under conditions that promote a thiol-ene reaction, wherein R 1 is a hydrocarbon linking group containing at least one carbon atom and X is a crosslinkable reactive group, to form the following intermediate (a):
wherein Z a and Z b independently represent remaining portions of the base polymer and x represents the molar percentage of segments that are attached to —S—R 1 —X throughout the base polymer; and
(iii) crosslinking between X groups of intermediate (a) species with a crosslinker of the formula Y a —R 2 —Y b , wherein R 2 is a hydrocarbon linking group containing at least one carbon atom and Y a and Y b are reactive with X to result in the following structure:
wherein L has the formula —S—R 1 —X—Y a —R 2 —Y b —X—R 1 —S—;
2× represents the molar percentage of segments that are linked with the linker L throughout the crosslinked polymeric composition;
R 2 is a hydrocarbon linking group containing at least one carbon atom;
X—Y a represents a dynamic reversible crosslinking group resulting from a reaction between a reactive group X and reactive group Y a ;
X—Y b represents a dynamic reversible crosslinking group resulting from a reaction between a reactive group X and reactive group Y b ; and
wherein X—Y a and X—Y b independently represent dynamic reversible crosslinking groups independently selected from the group consisting of imine (—C═N—) bonds, disulfide bonds, carboxy ester bonds, urea bonds, silyl ether bonds, vinylogous urethane, and urethane bonds.
7 . The method of claim 6 , wherein the base polymer is selected from the group consisting of acrylonitrile-butadiene-styrene, styrene-butadiene-styrene, styrene-butadiene, acrylonitrile-butadiene, polybutadiene, trans-polyisoprene, polynorbornene, and poly(aryl glycidyl ether) polymers.
8 . The method of claim 6 , wherein the base polymer contains a polybutadiene block.
9 . The method of claim 8 , wherein the base polymer is selected from the group consisting of acrylonitrile-butadiene-styrene (ABS), styrene-butadiene-styrene, styrene-butadiene, acrylonitrile-butadiene, and polybutadiene.
10 . The method of claim 6 , wherein X—Y a and X—Y b are imine (—C═N—) bonds.
11 . The method of claim 6 , wherein the base polymer is waste polymer.
12 . The method of claim 11 , wherein the waste polymer is waste ABS.
13 . A method of producing an object by additive manufacturing, the method comprising:
(i) incorporating a crosslinked polymer feed material into an additive manufacturing device; and
(ii) melting and extruding the crosslinked polymer feed material through a die of the additive manufacturing device and repeatedly depositing discrete amounts of a melted form of the crosslinked polymer feed material through the die to build a solid object layer-by-layer, and permitting the layers to cool and harden to form a solid object constructed of the crosslinked polymer feed material;
wherein the crosslinked polymer feed material comprises a base polymer containing unconjugated carbon-carbon double bonds of the formula —CR a ═CR b —, wherein a portion of said unconjugated carbon-carbon double bonds in said base polymer are interconnected by a crosslinker (L) as shown in the following structure:
wherein:
R a and R b are independently selected from hydrogen atom and hydrocarbon groups containing 1-6 carbon atoms, wherein, in the case where R a and R b are both hydrocarbon groups, said hydrocarbon groups optionally interconnect to form a ring;
2× represents the molar percentage of segments that are linked with the linker L throughout the crosslinked polymeric composition;
L is a crosslinker having the formula: —S—R 1 -L a -R 2 -L b -R 1 —S—;
R 1 and R 2 are independently selected from hydrocarbon linking groups containing at least one carbon atom;
L a and L b independently represent dynamic reversible crosslinking groups independently selected from the group consisting of imine (—C═N—) bonds, disulfide bonds, carboxy ester bonds, urea bonds, silyl ether bonds, vinylogous urethane, and urethane bonds; and
Z a and Z b independently represent remaining portions of the base polymer.
14 . The method of claim 13 , wherein the base polymer is selected from the group consisting of acrylonitrile-butadiene-styrene, styrene-butadiene-styrene, styrene-butadiene, acrylonitrile-butadiene, polybutadiene, polyisoprene, polynorbornene, and poly(aryl glycidyl ether) polymers.
15 . The method of claim 14 , wherein the base polymer contains a polybutadiene block.
16 . The method of claim 15 , wherein the crosslinked polymer feed material has the following structure:
wherein:
R a and R b are independently selected from hydrogen atom and hydrocarbon groups containing at least one carbon atom, wherein, in the case where R a and R b are both hydrocarbon groups, said hydrocarbon groups optionally interconnect to form a ring:
L is a crosslinker having the formula: —S—R 1 -L a -R 2 -L b -R 1 —S—;
R 1 and R 2 are independently selected from hydrocarbon linking groups containing at least one carbon atom;
L a and L b independently represent dynamic reversible crosslinking groups independently selected from the group consisting of imine (—C═N—) bonds, disulfide bonds, carboxy ester bonds, urea bonds, silyl ether bonds, vinylogous urethane, and urethane bonds:
subscript b corresponds to the molar percentage of butadiene units in the polybutadiene block and is an integer of at least 1;
A and B represent other polymerized units; and
subscripts a and c independently represent an integer of at least 1.
17 . The method of claim 15 , wherein the base polymer is selected from the group consisting of acrylonitrile-butadiene-styrene (ABS), styrene-butadiene-styrene, styrene-butadiene, acrylonitrile-butadiene, and polybutadiene.
18 . The method of claim 13 , wherein L a and L b are imine (—C═N—) bonds.