| 1. |
- Engström, Jonas, 1974, et al.
(författare)
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Functional beads of polyvinylpyrrolidone: promising support materials for solid-phase synthesis
- 2006
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Ingår i: Macromolecular Chemistry and Physics. ; 207:6, s. 605-614
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Tidskriftsartikel (refereegranskat)abstract
- 3-But-3-enyl-1-vinylpyrrolidin-2-one, 3,3-dibut-3-enyl-1-vinylpyrrolidin-2-one, 3-undec-10-enyl-1-vinylpyrrolidin-2-one, and 3,3-diundec-10-enyl-1-vinylpyrrolidin-2-one were prepd. and suspension polymd. to prep. hydrophilic polymer beads. Undec-10-en-1-ol was used as a comonomer for the introduction of functional groups. The lightly crosslinked beads contained hydroxyl groups at functional loading 0.28 mmol/g and swelled extensively in a broad range of solvents. [on SciFinder (R)]
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| 2. |
- Engström, Jonas, 1974
(författare)
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Functional Copolymers of Polyvinylpyrrolidone
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In many ways, polyvinylpyrrolidone (PVP) has a unique combination of chemical and physical properties. Unlike most polymers it is soluble in water as well as a number of organic solvents. PVP also has excellent film forming properties, outstanding chemical stability, complexing ability, low toxicity, and good adherence to many different substrates. PVP is therefore useful in numerous practical applications. In general, the inherent properties of PVP are utilized without modifications. However, the polymer lacks reactive functional groups, a limiting factor in many situations. Due to large differences in radical reactivity between 1-vinylpyrrolidin-2-one (NVP) and most other monomers, composition drift during copolymerization makes it very difficult to introduce functional groups or crosslinks in a controlled manner. Composition drift is best avoided by using monomers of equal reactivity. Attaching functional moieties to the alpha-position of NVP does not significantly alter the reactivity of the N-vinyl bond in a copolymerization. To use this approach, several functional monomers based on NVP itself were synthesized. From these NVP-derivatives, a number of functional PVP-based copolymers have been prepared. The copolymers are mainly intended for use as polymeric support materials in organic synthesis applications. Both soluble and crosslinked polymers were prepared for this purpose. The results from the soluble polymers show that the properties can be adjusted in terms of functionality, solubility, and molar mass. These polymers were suggested as attractive materials for drug delivery systems and phase-selectively soluble polymer supports for catalyst (or reagents). The unusual solubility profile of PVP was also successfully conveyed to crosslinked polymers. Lightly crosslinked beads of PVP could be prepared with useful loading capacities of functional groups and extensive swelling in several organic solvents as well as water. Naturally, this behaviour is very useful since the beads can be utilized as support materials in multi-step reaction sequences where several solvents of widely different polarity are used. This ability was demonstrated in the 5-step solid-phase synthesis of 5-(2,4,6-trimethoxy-phenyl)-cyclohexa-1,3-dienecarboxylic acid using polymer-bound cationic iron carbonyl complexes. In summary, the versatility of polyvinylpyrrolidone has been extended further since its properties can be easily tuned using copolymerization.
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| 3. |
- Engström, Jonas, 1974, et al.
(författare)
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Novel densely alkylated hydroxyl-functional polyvinylpyrrolidone showing phase-selective solubility
- 2006
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Ingår i: Macromolecular Chemistry and Physics. ; 207:12, s. 1062-1069
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Tidskriftsartikel (refereegranskat)abstract
- Polyvinylpyrrolidone (PVP) is a commonly used polymer with many different applications in the pharmaceutical, cosmetic and food industries. However, the lack of reactive groups and the difficulty in copolymg. the monomer, N-vinylpyrrolidin-2-one (NVP) with most other monomers, limits the possibility of modifying the phys. and chem. properties of the polymer. Monomers that are derivs. of NVP itself are expected to show small differences in radical reactivity as compared to the parent monomer and provide a way of adjusting the polymer properties without extensive compositional drift during copolymn. Here we present the synthesis of two new functionalized NVP-based monomers and their copolymn. with alkylated NVP-monomers for the prepn. of two functionalized PVPs with phase-selective soly. in heptane. Both copolymers showed 99.99% selective soly. in heptane over DMF (thermomorphic system) and 99.99% in heptane over 90% EtOH-H2O (latent biphasic system). These results suggest that the polymers could be used as sol. supports to facilitate recovery and recycling of catalysts or reagents from liq./liq. systems after homogeneous reactions. [on SciFinder (R)]
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| 4. |
- Engström, Jonas, 1974, et al.
(författare)
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Synthesis of novel monomers and copolymers from 1-vinylpyrrolidin-2-one: attractive materials for drug delivery systems?
- 2006
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Ingår i: Macromolecular Chemistry and Physics. ; 207:5, s. 536-544
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Tidskriftsartikel (refereegranskat)abstract
- Polyvinylpyrrolidone (PVP) is a synthetic, non-toxic, water-sol. polymer commonly used in a wide range of applications including several pharmaceutical applications. One example of an important application is the controlled release and delivery of therapeutic agents into sites of inflammation or tumors. However, PVP lacks reactive groups, which limits the possibility of adding new functions to the polymer in order to modify its phys. and chem. properties. Furthermore, large differences in radical reactivity between 1-vinylpyrrolidin-2-one (NVP) and most other monomers lead to compositional drift during copolymn. This complicates the introduction of reactive groups into the polymer using this method. Monomers that are derivs. of NVP itself are expected to show smaller differences in radical reactivity and therefore provide a way of prepg. PVP with adjustable properties. Here we present the synthesis of five NVP-based monomers and their use in the prepn. of functional PVP with adjustable properties in terms of soly., loading of functional groups, and molar mass. The results show the possibility of tailoring PVP for different biomedical applications e.g. drug delivery systems. [on SciFinder (R)]
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