Enzymatic Synthesis of Functional Polyesters
Enzymes are successfully employed in the synthesis of different types of polymers. Candida antarctica lipase B is a highly efficient catalyst for the synthesis of polyesters by ring opening polymerization. ω-Pentadecalactone is an interesting lactone due to the unique proprieties of its polymer (pol...
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KTH, Biokemi
2008
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ftkthstockholm:oai:DiVA.org:kth-4641 2023-05-15T13:31:19+02:00 Enzymatic Synthesis of Functional Polyesters Takwa, Mohamad 2008 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4641 eng eng KTH, Biokemi Stockholm : KTH http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4641 urn:isbn:978-91-7178-881-8 info:eu-repo/semantics/openAccess Biochemistry and Molecular Biology Biokemi och molekylärbiologi Licentiate thesis, comprehensive summary info:eu-repo/semantics/masterThesis text 2008 ftkthstockholm 2022-08-11T12:38:45Z Enzymes are successfully employed in the synthesis of different types of polymers. Candida antarctica lipase B is a highly efficient catalyst for the synthesis of polyesters by ring opening polymerization. ω-Pentadecalactone is an interesting lactone due to the unique proprieties of its polymer (poly-pentadecalactone). These polymers have not been applied in any industrial application due to the difficulties to reach them by chemical polymerization. Enzymatically, poly-pentadecalactone macromonomers can be obtained to high conversion. In this investigation we synthesized difunctionalized poly-pentadecalactone with different functional groups. Taking advantage of the selectivity of Candida antarctica lipase B, we introduced different functional end groups. α,ω-Difunctionalized poly-pentadecalactone macromonomers with two thiol ends, two (meth)acrylate ends or with one thiol and one acrylate end were obtained with a high degree of functional ends. We have improved the difunctionalization procedure to a single-step route for the synthesis of α,ω-functionalized poly-pentadecalactones. This procedure has a great potential for industrial applications due to the simplicity of the process and the clean products afforded. Macromonomers with functionalized ends can be used to obtain new polymer architectures with novel proprieties. We also show how the use of enzymes could have some limitations when using an initiator with a cleavable ester bond. 2-Hydroxyethyl methacrylate (HEMA) was used as initiator for the ring opening polymerization (eROP) of ε-caprolactone and ω-pentadecalactone aiming for methacrylate functional polyester. However, the lipase catalyzed not only the ring opening polymerization but also the cleavage of the HEMA moiety resulting in a mixture of polymer products with various end groups. A kinetics study of the eROP and the transesterification processes when using HEMA showed that the transesterification processes occurs at moderate frequency at low monomer concentration, it becomes dominant at longer ... Master Thesis Antarc* Antarctica Royal Institute of Technology, Stockholm: KTHs Publication Database DiVA |
institution |
Open Polar |
collection |
Royal Institute of Technology, Stockholm: KTHs Publication Database DiVA |
op_collection_id |
ftkthstockholm |
language |
English |
topic |
Biochemistry and Molecular Biology Biokemi och molekylärbiologi |
spellingShingle |
Biochemistry and Molecular Biology Biokemi och molekylärbiologi Takwa, Mohamad Enzymatic Synthesis of Functional Polyesters |
topic_facet |
Biochemistry and Molecular Biology Biokemi och molekylärbiologi |
description |
Enzymes are successfully employed in the synthesis of different types of polymers. Candida antarctica lipase B is a highly efficient catalyst for the synthesis of polyesters by ring opening polymerization. ω-Pentadecalactone is an interesting lactone due to the unique proprieties of its polymer (poly-pentadecalactone). These polymers have not been applied in any industrial application due to the difficulties to reach them by chemical polymerization. Enzymatically, poly-pentadecalactone macromonomers can be obtained to high conversion. In this investigation we synthesized difunctionalized poly-pentadecalactone with different functional groups. Taking advantage of the selectivity of Candida antarctica lipase B, we introduced different functional end groups. α,ω-Difunctionalized poly-pentadecalactone macromonomers with two thiol ends, two (meth)acrylate ends or with one thiol and one acrylate end were obtained with a high degree of functional ends. We have improved the difunctionalization procedure to a single-step route for the synthesis of α,ω-functionalized poly-pentadecalactones. This procedure has a great potential for industrial applications due to the simplicity of the process and the clean products afforded. Macromonomers with functionalized ends can be used to obtain new polymer architectures with novel proprieties. We also show how the use of enzymes could have some limitations when using an initiator with a cleavable ester bond. 2-Hydroxyethyl methacrylate (HEMA) was used as initiator for the ring opening polymerization (eROP) of ε-caprolactone and ω-pentadecalactone aiming for methacrylate functional polyester. However, the lipase catalyzed not only the ring opening polymerization but also the cleavage of the HEMA moiety resulting in a mixture of polymer products with various end groups. A kinetics study of the eROP and the transesterification processes when using HEMA showed that the transesterification processes occurs at moderate frequency at low monomer concentration, it becomes dominant at longer ... |
format |
Master Thesis |
author |
Takwa, Mohamad |
author_facet |
Takwa, Mohamad |
author_sort |
Takwa, Mohamad |
title |
Enzymatic Synthesis of Functional Polyesters |
title_short |
Enzymatic Synthesis of Functional Polyesters |
title_full |
Enzymatic Synthesis of Functional Polyesters |
title_fullStr |
Enzymatic Synthesis of Functional Polyesters |
title_full_unstemmed |
Enzymatic Synthesis of Functional Polyesters |
title_sort |
enzymatic synthesis of functional polyesters |
publisher |
KTH, Biokemi |
publishDate |
2008 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4641 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4641 urn:isbn:978-91-7178-881-8 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766017474046722048 |