8. Anhydrous dichloromethane !99%.
9. Propylene carbonate.
10. Lucirin TPO-L (ethyl 2,4,6-trimethylbenzoylphenyl phosphinate, BASF) photoinitiator.
11. Orasol Orange G (Ciba Specialty Chemicals) to control the
degree of penetration of blue light in the resin.
12. Three-necked flask. Dry for several hours in an oven at 100
C
prior to use.
13. Crosslinking cabinet (Ultralum).
14. Stereolithographic 3D printer (Perfactory Mini Multilens,
EnvisionTec).
3 Methods
3.1 Synthesis
of the Biodegradable
and Biocompatible
Three-Armed
Oligomers by Ring
Opening
Polymerization
Two types of biocompatible and biodegradable polymeric materials
are investigated to prepare the TPMS scaffolds, materials based on
poly(trimethylene carbonate) (PTMC) and poly(D,L-lactide)
(PDLLA). A multi-gram production of polymer resin is afforded
with predetermined molecular weights. Low chain length is preferred to facilitate the end-functionalization and the crosslinking
steps. The configuration of the polymer (single arm, star-shaped,
etc.) is determined by the initiator molecule, and the molecular
weight can be adjusted by varying the monomer to the initiator
molar ratio. Three-armed and hydroxy-terminated oligomers targeting 5000 g/mol as global chain length are synthesized. The
targeted molecular weight of 5000 g/mol corresponds to an
approximate degree of polymerization of 16 trimethylene carbonate units per arm and an approximate degree of polymerization of
23 lactic acid units per arm.
All manipulations must be performed in a fume hood. The
experimenter must wear a lab coat and gloves during all the different chemical steps.
1. To synthesize three-armed PTMC, add TMC monomer
(0.98 mol; 100 g), Sn(Oct) 2 catalyst (0.05 wt% of monomer),
and TMP initiator (0.0196 mol; 2.62 g) (see Note 1). Add the
compounds under argon into the dried flask, and apply to the
mixture 10 cycles of vacuum and argon backfill at room temperature and under stirring (see Note 2).
2. Perform bulk polymerization for 48 h in argon atmosphere at
130
C by heating with an oil bath.
3. Same protocol can be adjusted for the synthesis of poly(D,Llactide) oligomers. Three-armed PDLLA oligomer synthesis is
performed by ring opening polymerization of D,L-lactide
(0.694 mol; 100 g), catalyzed by Sn(Oct) 2 (0.05 wt% of
22
Sebastien B. G. Blanquer and Dirk W. Grijpma
9. Propylene carbonate.
10. Lucirin TPO-L (ethyl 2,4,6-trimethylbenzoylphenyl phosphinate, BASF) photoinitiator.
11. Orasol Orange G (Ciba Specialty Chemicals) to control the
degree of penetration of blue light in the resin.
12. Three-necked flask. Dry for several hours in an oven at 100
C
prior to use.
13. Crosslinking cabinet (Ultralum).
14. Stereolithographic 3D printer (Perfactory Mini Multilens,
EnvisionTec).
3 Methods
3.1 Synthesis
of the Biodegradable
and Biocompatible
Three-Armed
Oligomers by Ring
Opening
Polymerization
Two types of biocompatible and biodegradable polymeric materials
are investigated to prepare the TPMS scaffolds, materials based on
poly(trimethylene carbonate) (PTMC) and poly(D,L-lactide)
(PDLLA). A multi-gram production of polymer resin is afforded
with predetermined molecular weights. Low chain length is preferred to facilitate the end-functionalization and the crosslinking
steps. The configuration of the polymer (single arm, star-shaped,
etc.) is determined by the initiator molecule, and the molecular
weight can be adjusted by varying the monomer to the initiator
molar ratio. Three-armed and hydroxy-terminated oligomers targeting 5000 g/mol as global chain length are synthesized. The
targeted molecular weight of 5000 g/mol corresponds to an
approximate degree of polymerization of 16 trimethylene carbonate units per arm and an approximate degree of polymerization of
23 lactic acid units per arm.
All manipulations must be performed in a fume hood. The
experimenter must wear a lab coat and gloves during all the different chemical steps.
1. To synthesize three-armed PTMC, add TMC monomer
(0.98 mol; 100 g), Sn(Oct) 2 catalyst (0.05 wt% of monomer),
and TMP initiator (0.0196 mol; 2.62 g) (see Note 1). Add the
compounds under argon into the dried flask, and apply to the
mixture 10 cycles of vacuum and argon backfill at room temperature and under stirring (see Note 2).
2. Perform bulk polymerization for 48 h in argon atmosphere at
130
C by heating with an oil bath.
3. Same protocol can be adjusted for the synthesis of poly(D,Llactide) oligomers. Three-armed PDLLA oligomer synthesis is
performed by ring opening polymerization of D,L-lactide
(0.694 mol; 100 g), catalyzed by Sn(Oct) 2 (0.05 wt% of
22
Sebastien B. G. Blanquer and Dirk W. Grijpma