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Chemo-enzymatic synthesis of comb polymers
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
Centre for Polymer Science and Engineering, Indian Institute of Technology, Delhi.
Centre for Polymer Science and Engineering, Indian Institute of Technology, Delhi.
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.ORCID-id: 0000-0001-8696-9143
2007 (engelsk)Inngår i: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 43, nr 3, s. 808-817Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The paper describes the synthesis and characterization of comb polymers by a two-step chemo-enzymatic process. In the first step macromonomers bearing unsaturation at the chain end were prepared by lipase catalyzed ring-opening polymerization (ROP) of E-caprolactone (CL) and 1,5-dioxepane-2-one (DXO). The ROP was carried out in bulk at 60 degrees C under anhydrous conditions using 2-hydroxyethyl methacrylate (HEMA) as the initiator. The DP of the macromonomers was controlled by regulating the monomer: HEMA molar feed concentration. The macromonomers were then homo- or co-polymerized in the second step with alkyl methacrylate monomers (methyl methacrylate or HEMA) using AIBN initiated free radical polymerization. Characterization of the polymers was done by H-1 NMR, SEC and DSC techniques.

sted, utgiver, år, opplag, sider
2007. Vol. 43, nr 3, s. 808-817
Emneord [en]
1, 5-Dioxepane-2-one; Comb polymers; Enzyme; Lipase-CA; Ring-opening polymerization; Copolymerization; Enzymes; Free radical polymerization; Macromolecules; Ring opening polymerization; Saturation (materials composition); Synthesis (chemical); 1, 5-Dioxepane-2-one; 2-hydroxyethyl methacrylate (HEMA); Caprolactone (CL); Comb polymers; Lipase-CA; Macromonomers; Organic polymers
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-7007DOI: 10.1016/j.eurpolymj.2006.11.032ISI: 000245064900014Scopus ID: 2-s2.0-33847037905OAI: oai:DiVA.org:kth-7007DiVA, id: diva2:11881
Merknad
QC 20100818Tilgjengelig fra: 2007-04-20 Laget: 2007-04-20 Sist oppdatert: 2022-06-26bibliografisk kontrollert
Inngår i avhandling
1. Aliphatic Polyesters for Soft Tissue Engineering: Development from Conventional Organometallic to Novel Enzymatic Catalysis
Åpne denne publikasjonen i ny fane eller vindu >>Aliphatic Polyesters for Soft Tissue Engineering: Development from Conventional Organometallic to Novel Enzymatic Catalysis
2007 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

The development of macromolecules with defined structure and properties, aimed specifically for biomedical applications, has resulted in diverse biodegradable polymers with advanced architectures. Among them, aliphatic polyesters synthesized by ring-opening polymerization (ROP) of lactones and lactides have a leading position due to their good mechanical properties, hydrolyzability and biocompatibility. To achieve tailored properties and controlled architecture, the technique for ROP of lactones and lactides has been continuously refined in the past years. Enzyme-catalyzed ROP is one of the most promising tools, which avoids the use of toxic organometallic catalysts and brings a “green-chemistry” appeal with it. In the work described in this thesis, enzyme-catalyzed ROP of 1,5-dioxepan-2-one (DXO), ε-caprolactone (CL) and lactides (L-, D- and D,L-lactide) was performed in bulk using Lipases from different sources. The effects of enzyme concentration, polymerization temperature and reaction water content on the monomer conversion and the polymer molecular weight during DXO polymerization were studied, and the role of water as initiator was confirmed. Terminal functionalized, block, comb and star polymers were synthesized using different alcohols as initiator in the enzyme-catalyzed ROP of DXO, CL or lactides under strictly anhydrous conditions. The effect of simultaneous and sequential copolymerization of DXO and CL on the micro-block structure of the copolymers was studied and the reactivity ratios of DXO and CL were determined under Lipase catalysis. High molecular weight copolymers of DXO and CL thus obtained were fabricated into porous scaffolds for tissue implant applications. Enzymatic degradation and alkaline hydrolysis of lactides was performed to study the effect of molecular branches and the stereochemistry of the monomer on the degradation profile. In another approach, cross-linked films of DXO and CL were prepared using 2,2´-bis-(ε-caprolactone-4-yl) propane (BCP) as the cross-linking agent and Sn(Oct)2 as the catalyst. The networks obtained thereof were elastomeric materials, easy to cast and remove from the mould.

sted, utgiver, år, opplag, sider
Stockholm: KTH, 2007. s. 125
Serie
Trita-CHE-Report, ISSN 1654-1081 ; 2007:2
Emneord
aliphatic polyester, 1, 5-dioxepan-2-one, ε-caprolactone, L-lactide, D-lactide, D, L-lactide, enzyme, lipase CA, lipase PS
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-4341 (URN)978-91-7178-595-4 (ISBN)
Disputas
2007-05-04, F3, KTH, Lindstedtsvägen 26, Stoclholm, 10:15
Opponent
Veileder
Merknad
QC 20100818Tilgjengelig fra: 2007-04-20 Laget: 2007-04-20 Sist oppdatert: 2022-06-26bibliografisk kontrollert

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