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Degradable High Tg Sugar Derived Polycarbonates from Isosorbide and Dihydroxyacetone
KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.ORCID-id: 0000-0001-7543-5322
KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.ORCID-id: 0000-0001-6112-0450
KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.ORCID-id: 0000-0002-9486-5288
KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.ORCID-id: 0000-0002-8474-9478
Vise andre og tillknytning
2018 (engelsk)Inngår i: Polymer Chemistry, ISSN 1759-9954, E-ISSN 1759-9962, Vol. 9, nr 17, s. 2238-2246Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Polycarbonates from isosorbide and dihydroxyacetone (DHA) have been synthesised using organocatalytic step-growth polymerization of their corresponding diols and bis-carbonylimidazolides monomers. By choice of feed ratio and monomer activation, either isosorbide or ketal protected DHA, random and alternating poly(Iso-co-DHA) carbonates have been formed. Thermal properties by DSC and TGA were herein strongly correlated to monomer composition. Dilution studies using 1H-NMR of a model compound DHA-diethyl carbonate in acetonitrile and deuterated water highlighted the influence of α-substituents on the keto/hydrate equilibrium of DHA. Further kinetics studies of in the pH* range of 4.7 to 9.6 serve to show the hydrolytic pH-profile of DHA-carbonates. The Hydrolytic degradation of deprotected polymer pellets show an increased degradation with increasing DHA content. Pellets with a random or alternating configuration show different characteristics in terms of mass loss and molecular weight loss profile over time.

sted, utgiver, år, opplag, sider
Royal Society of Chemistry, 2018. Vol. 9, nr 17, s. 2238-2246
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-224753DOI: 10.1039/C8PY00256HISI: 000431183700004Scopus ID: 2-s2.0-85046299922OAI: oai:DiVA.org:kth-224753DiVA, id: diva2:1192335
Forskningsfinansiär
Swedish Research Council, 2011-5358 2010-435 2015-04779Knut and Alice Wallenberg Foundation, 2012-0196
Merknad

QC 20180322

Tilgjengelig fra: 2018-03-22 Laget: 2018-03-22 Sist oppdatert: 2019-10-10bibliografisk kontrollert
Inngår i avhandling
1. Versatile Synthetic Strategies to Highly Functional Polyesters and Polycarbonates
Åpne denne publikasjonen i ny fane eller vindu >>Versatile Synthetic Strategies to Highly Functional Polyesters and Polycarbonates
2018 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Polymers have become ubiquitous in today’s society and are found in everything from household items to airplanes and automobiles. Synthetic polymeric materials are as diverse as their applications and their final properties are highly reliant on the building blocks and methods used to assemble them. In the field of biomedical materials, polyesters and polycarbonates have been hailed as excellent materials in large part due to their inherent hydrolytic degradability. With this in mind, careful choice of monomers can ensure that materials not only conform to the desired physical properties, but also elicit a favorable biological response. The utilization of post-polymerization modification of these promising materials has the capability of opening up further avenues to target even more advanced applications. Unfortunately, rigorous and difficult reaction conditions, including multi-step synthesis have to a certain extent held back the adoption of these complex functional materials in applied research. In a pragmatic approach, a sustainable framework was developed in this thesis to seek out more practical methods, limiting the amount of reaction steps and overtly hazardous chemicals.

In a first study, we set out to simplify and scale-up the synthesis of cyclic carbonates with pendant functional groups, capable of undergoing controlled ring-opening polymerization. By avoiding the use of protective-group chemistry we were able two devise a two-step method to create a library of functional monomers. Results in this study show that reactive intermediates could be isolated on 100 g scales, which in a second step was functionalized with a desired alcohol.

With this framework in mind, key practical decisions were made to drastically re-think the work up procedures for greater scalability of bis-MPA dendrimers. In this work, a more efficient, scalable and sustainable approach was devised. Elimination of traditional arduous purification steps led to the synthesis of monodisperse dendrimers up to the sixth generation, with 192 functional groups on 50 g scales. Further work included the omission of protective group-chemistry, using orthogonal functional groups to cut the number of synthetic steps by half.

The know-how developed in the first two projects led us to pursue greater scalability of functional polycarbonates through a simpler polymerization technique. The method allowed the step-growth polymerization of functional materials from more easily accessible monomers isolated on 100 g scales. Subsequent polymerization afforded materials with glass transition temperatures in the range of -45 °C to 169 °C. The method served as a complement to cyclic carbonates, offering a wider range of functional monomers. Furthermore, by careful choice of assembly method, both alternating and scrambled compositions could be achieved.

In a final study, we set out to take advantage of the scrambling mechanism. Control of the final composition of highly rigid degradable polycarbonates was pursued, using renewable building-blocks derived from sugar. In a proof of concept study, thermal and hydrolytic stability of these materials is shown to be dependent on both amount and configuration of each monomer in the final material.

sted, utgiver, år, opplag, sider
KTH Royal Institute of Technology, 2018. s. 60
Serie
TRITA-CBH-FOU ; 2018:6
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-224754 (URN)978-91-7729-711-6 (ISBN)
Disputas
2018-04-13, Kollegiesalen, Brinellvägen 8, Stockholm, 10:00 (engelsk)
Opponent
Veileder
Merknad

QC 20180322

Tilgjengelig fra: 2018-03-22 Laget: 2018-03-22 Sist oppdatert: 2018-03-22bibliografisk kontrollert

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