Grafted Fluoropolymers as Supports for Solid-Phase Organic Chemistry: Preparation and Characterization

Dargaville, Tim R.; Hill, David J. T.; Perera, Senake

doi:10.1071/ch02072

Cited by 12 publications

(9 citation statements)

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“…Another notable feature of the graft profiles is that a dip in the PS graft proportion is observed at the surface of the supports (at 0 µm). This feature has been observed in other studies for polypropylene8, 9 and fluoropolymer14, 15 supports. One possible explanation for this feature is that the crystallinity at the surface of the polymer is higher, resulting from shear‐induced crystallisation of surface polymer during injection moulding.…”

Section: Resultssupporting

confidence: 87%

Applications of Multicomponent Reactions to the Synthesis of Diverse Heterocyclic Scaffolds

Sunderhaus

Martin

2009

Chemistry A European J

694

174

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The sequencing of multicomponent reactions (MCRs) and subsequent cyclization reactions is a powerful stratagem for the rapid synthesis of diverse heterocyclic scaffolds. The optimal MCR is sufficiently flexible that it can be employed to generate adducts bearing a variety of functional groups that may then be selectively paired to enable different cyclization manifolds, thereby leading to a diverse collection of products. The growing interest in diversity-oriented synthesis has led to increased attention to this paradigm for library synthesis, which has inspired many advances in the design and implementation of MCRs for the construction of diverse heterocyclic scaffolds.

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Section: Resultssupporting

confidence: 87%

Applications of Multicomponent Reactions to the Synthesis of Diverse Heterocyclic Scaffolds

Sunderhaus

Martin

2009

Chemistry A European J

694

174

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“…The observed UV−vis signal of grafted chain fragments can however result from washed-out occluded polymer chains, since entangled polymer chains can be relatively immobile inside the polymer networks and may remain in the membrane after preparation. 43 The thermal stress test experiment under air atmosphere was therefore extended to 7 days to test this hypothesis. The absorbance signature of the decomposition products in the water continued to increase in apparent linear manner.…”

Section: Resultsmentioning

confidence: 99%

Stability and Degradation Mechanisms of Radiation-Grafted Polymer Electrolyte Membranes for Water Electrolysis

Albert

Lochner

Schmidt

et al. 2016

ACS Appl. Mater. Interfaces

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Radiation-grafted membranes are a promising alternative to commercial membranes for water electrolyzers, since they exhibit lower hydrogen crossover and area resistance, better mechanical properties, and are of potentially lower cost than perfluoroalkylsulfonic acid membranes, such as Nafion. Stability is an important factor in view of the expected lifetime of 40 000 h or more of an electrolyzer. In this study, combinations of styrene (St), α-methylstyrene (AMS), acrylonitrile (AN), and 1,3-diisopropenylbenzene (DiPB) are cografted into 50 μm preirradiated poly(ethylene-co-tetrafluoroethylene) (ETFE) base film, followed by sulfonation to produce radiation-grafted membranes. The stability of the membranes with different monomer combinations is compared under an accelerated stress test (AST), and the degradation mechanisms are investigated. To mimic the conditions in an electrolyzer, in which the membrane is always in contact with liquid water at elevated temperature, the membranes are immersed in water for 5 days at 90 °C, so-called thermal stress test (TST). In addition to testing in air atmosphere tests are also carried out under argon to investigate the effect of the absence of oxygen. The water is analyzed with UV-vis spectroscopy and ion chromatography. The ion exchange capacity (IEC), swelling degree, and Fourier transform infrared (FTIR) spectra of the membranes are compared before and after the test. Furthermore, energy-dispersive X-ray (EDX) spectroscopic analysis of the membrane cross-section is performed. Finally, the influence of the TST to the membrane area resistance and hydrogen crossover is measured. The stability increases along the sequence St/AN, St/AN/DiPB, AMS/AN, and AMS/AN/DiPB grafted membrane. The degradation at the weak-link, oxygen-induced degradation, and hydrothermal degradation are proposed in addition to the "swelling-induced detachment" reported in the literature. By mitigating the possible paths of degradation, the AMS/AN/DiPB grafted membrane is shown to be the most stable membrane and, therefore, it is a promising candidate for a membrane to be used in a water electrolyzer.

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“…27 One such study compared the molecular mass of the homopolymer formed in solution and that which formed occluded at the surface of a grafted substrate. 105 It was found that the occluded homopolymer had a significantly higher molecular mass (approximately one order of magnitude) than that which formed in the surrounding solution and this was regardless of the solvent used during the grafting reaction. 105 This was rationalised based on the different viscosity near the substrate and in solution with the higher viscosity region decreasing chain mobility and therefore termination.…”

Section: Characterisation Of Grafted Chainsmentioning

confidence: 98%

CHAPTER 11. Grafting of Functional Monomers on Biomaterials

Grøndahl¹,

Luk²

2014

Smart Materials Series

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Grafted Fluoropolymers as Supports for Solid-Phase Organic Chemistry: Preparation and Characterization

Cited by 12 publications

References 0 publications

Applications of Multicomponent Reactions to the Synthesis of Diverse Heterocyclic Scaffolds

Applications of Multicomponent Reactions to the Synthesis of Diverse Heterocyclic Scaffolds

Stability and Degradation Mechanisms of Radiation-Grafted Polymer Electrolyte Membranes for Water Electrolysis

CHAPTER 11. Grafting of Functional Monomers on Biomaterials

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