USE OF MULTIBLOCK COPOLYMERS AS SACRIFICIAL MATERIAL IN A 3D PRINTING PROCESS

1 . At least one multiblock copolymer (I) suitable as sacrificial material in a process for 3D printing polymers, the Tg of which is between 140 and 200°, chosen from PEEK, PEKK, PEK, PEKEKK, PEEKK, PEKK, PEI, PAI, PSU and PPS, wherein the at least one multiblock copolymer (I) comprises:

at least one block consisting of i monomers M i linked together randomly, i being an integer ranging from 2 to 5, limits included, and

at least one block consisting of j monomers M j linked together randomly, j being an integer ranging from 2 to 5, limits included,

wherein M i is selected from monomers A, the Tg of the homopolymers of which is less than 0° C., and hydrophilic monomers B, the proportion by mass of A ranging from 80% to 95% and the proportion by mass of B ranging from 5% to 20%,

wherein M j is selected from monomers C, the Tg of the homopolymers of which is less than 0° C., monomers D, the Tg of the homopolymers of which is greater than 25° C., and hydrophilic monomers E, the proportions by mass of the monomers C, D and E being respectively between 25-35%, 25-35% and 35-45%.

2 . The at least one multiblock copolymer (I) as claimed in claim 1 , wherein at least one block copolymer (II) is present in a proportion by mass of between 1% and 50% of the total weight of (I)+(II).

3 . The at least one multiblock copolymer (I) as claimed in claim 1 , wherein the at least one block copolymer (I) is a diblock copolymer or a triblock copolymer.

4 . The at least one multiblock copolymer (I) as claimed in claim 3 , wherein the block copolymer (I) is a diblock copolymer.

5 . The at least one multiblock copolymer (I) as claimed in claim 4 , wherein the diblock copolymer (I) has a proportion by mass of the blocks consisting of the monomers of the family A and B ranging from 5% to 40% (block 1) and a proportion by mass of the blocks consisting of the monomers C, D and E ranging from 50% to 90% (block 2).

6 . The at least one multiblock copolymer (I) as claimed in claim 1 , wherein the copolymer (II) has at least one block the glass transition temperature of which is less than 0° C. and at least one block the glass transition temperature of which is greater than 0° C.

7 . The at least one multiblock copolymer (I) as claimed in claim 1 , wherein the block copolymers are prepared by controlled radical polymerization.

8 . The at least one multiblock copolymer (I) as claimed in claim 7 , wherein the block copolymers are prepared by nitroxide-mediated radical polymerization.

9 . The at least one multiblock copolymer (I) as claimed in claim 8 , wherein the block copolymers are prepared by radical polymerization mediated by N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide.

10 . The at least one multiblock copolymer (I) as claimed in claim 8 , wherein at least one block copolymer (I) consists of blocks 1 employing butyl acrylate and acrylic acid and of blocks 2 employing butyl acrylate, styrene and methacrylic acid.

11 . The at least one multiblock copolymer (I) as claimed in claim 1 , wherein at least one block copolymer (I) has a weight-average molecular mass of between 80 000 g/mol and 150 000 g/mol.

12 . The at least one multiblock copolymer (I) as claimed in claim 2 , wherein the copolymer (II) has a weight-average molecular mass of between 50 000 g/mol and 150 000 g/mol.

13 . The use of the at least one multiblock copolymer (I) as claimed in claim 1 as sacrificial material in a process for 3D printing polymers.