Systematic comparison of HEA and HEMA as initiators in enzymatic ring-opening polymerizations.
Two initiators containing a cleavable ester bond were compared in the lipase-catalyzed ROP of CL and PDL. The results show that transesterification reactions are present at high rates throughout the enzymatic ROP and start at low conversion. HEA and HEMA displayed similar reaction efficiencies as initiators (acyl acceptors) in the enzymatic ROP. However, transacylation reactions on the HEA-initiated polyesters were found to be 15 times faster. While in both cases the amount of HEA- and HEMA-initiated polymers could be maximized by short reaction times, a well-defined (meth)acrylation by this approach was not possible. Our results show that transesterification reactions have to be considered when performing an enzyme-catalyzed ROP.
Xiao
Yan
Y
Eindhoven University of Technology, Department of Polymer Chemistry, PO Box 513, 5600 MB Eindhoven, The Netherlands.
Takwa
Mohamad
M
Hult
Karl
K
Koning
Cor E
CE
Heise
Andreas
A
Martinelle
Mats
M
D000179:Acrylates / Q000737:chemistry*; D002384:Catalysis; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008689:Methacrylates / Q000737:chemistry*; D015394:Molecular Structure; D011091:Polyesters / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*
D000179:Acrylates; D008689:Methacrylates; D011091:Polyesters; D011108:Polymers; C035957:2-hydroxyethyl acrylate; C005044:hydroxyethyl methacrylate