Lecture Anja Palmans
|21 januari 2005||FWN-Building 5114.0004, Nijenborgh 4, 9747 AG, Groningen|
|Affiliation:||Laboratory of Macromolecular and Organic Chemistry, Technical University Eindhoven|
|Title:||Cascade polymerisation reactions|
|Date:||Fri Jan 21, 2005|
|Telephone:||+31 50 363 6867|
The enantioselective polymerisation of methyl substituted e-caprolactones using Novozym 435 as the catalyst was investigated. All substituted monomers could be polymerised except 6-methyl-e-caprolactone which failed to propagated after ring opening. Interestingly, an odd-even effect in the enantiopreference of differently substituted monomers was observed. The combination of 4-methyl-e-caprolactone (4-MeCL) with Novozym 435 showed a good enantioselectivity (E = 10-35) under different conditions of concentration and solvent nature and resulted in enantio-enriched poly-(S)-4-MeCL (eep = 0.88).
Faster reaction enantiomers in Novozym 435 catalysed ring opening polymerisations In addition, a cascade approach for the synthesis of block copolymers combining enzymatic ring opening polymerization and controlled living free radical polymerization from a bifunctional initiator is presented. Block copolymers comprising a poly(styrene) and poly(caprolactone) block were obtained in two consecutive polymerization steps (macroinitiation) and in a one-pot cascade approach without intermediate transformation or work up step. The same concept was successfully extended to enzymatic resolution polymerization of racemic 4-MeCL combined with the living free radical polymerization of styrene or methyl methacrylate yielding block copolymers of high enantiomeric excess in the 4-MeCL block.
|Laatst gewijzigd:||22 oktober 2012 14:31|