The application of a novel profluorescent nitroxide to monitor thermo-oxidative degradation of polypropylene

Micallef, Aaron S.; Blinco, James P.; George, Graeme A.; Reid, Damien A.; Rizzardo, Ezio; Thang, San H.; Bottle, Steven E.

doi:10.1016/j.polymdegradstab.2005.01.030

Cited by 64 publications

(53 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Notably after 30 h, significant fluorescence could be detected, yet the polymer displayed no visible indication of degradation. This mirrors the performance in thermooxidative degradation [11] where profluorescent nitroxides impart stability into the polymer matrix and signal the levels of radical degradation reactions occurring. Notably there was no increase in fluorescence from polypropylene blanks photolysed under the same conditions.…”

Section: Resultsmentioning

confidence: 84%

“…To demonstrate the application of TMAO as a probe, it was incorporated into polypropylene at low levels (Ͻ0.05 %) by using established methodology. [11] The polymer was irradiated in a Heraeus Sun Test CPS+ at an energy of Figure 3. Notably after 30 h, significant fluorescence could be detected, yet the polymer displayed no visible indication of degradation.…”

Section: Resultsmentioning

confidence: 99%

“…Profluorescent probes synthesised to date, however, commonly link the fluorophore to the nitroxide through ester, amine, amide or sulfonamide groups. We recently showed that it is possible to combine phenanthrene [11] and stilbene [12] fluorophores with an isoindoline nitroxide in a C-C bond framework that is not susceptible to hydrolysis or enzymatic cleavage. These fused aromatic nitroxides also exhibit some advantages over less rigid fiveand six-membered nitroxides, including superior thermal and chemical stability and narrower EPR linewidths.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The First Example of an Azaphenalene Profluorescent Nitroxide

Blinco¹,

McMurtrie²,

Bottle³

2007

Eur J Org Chem

Self Cite

View full text Add to dashboard Cite

The synthesis of the first example of an azaphenalene‐based fused aromatic nitroxide TMAO, [1,1,3,3‐tetramethyl‐2,3‐dihydro‐2‐azaphenalen‐2‐yloxyl, (5)], is described. This novel nitroxide possesses some of the structural rigidity of the isoindoline class of nitroxides, as well as some properties akin to TEMPO nitroxides. Additionally, the integral aromatic ring imparts fluorescence that is switched on by radical scavenging reactions of the nitroxide, which makes it a sensitive probe for polymer degradation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

show abstract

Section: Resultsmentioning

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The First Example of an Azaphenalene Profluorescent Nitroxide

Blinco¹,

McMurtrie²,

Bottle³

2007

Eur J Org Chem

Self Cite

View full text Add to dashboard Cite

show abstract

“…The cleavage of the covalent connection between both moieties would negate the quenching performance. 128 Therefore, the connection of commercially available nitroxides and fluorophores via esterification, 122,123,[129][130][131][132][133][134] amidation, [135][136][137] or sulfonamidation [138][139][140] employed in the early stages of the PFN research are less suitable for efficient PFNs (refer to Scheme 10). The resulting compounds contain long, hydrolysis sensitive linkages.…”

Section: Synthesismentioning

confidence: 99%

“…158 Thermal polymer degradation has also been investigated extensively, including studies on initiator free, 128 as well as AIBN 159 and peroxide 144 doped polymer samples.…”

Section: Figurementioning

confidence: 99%

From UV to NIR light, photo-triggered 1,3 dipolar cycloadditions as a modern ligation method in solution and on surface

Lederhose¹

View full text Add to dashboard Cite

angefertigt.Ich erkläre hiermit, dass ich die vorliegende Arbeit im Rahmen der Betreuung durch Prof. tracking. In addition, the trigger wavelength of the pyrene functionalized tetrazole was extended deep into the NIR range via the combination of the NITEC with upconversion nanoparticles (UCNPs). Assisted by the UCNPs, photoinduced ligation of both, small and macromolecules was obtained with irradiation at 974 nm. Full conversion and rapid formation of the desired pyrazoline cycloadducts were observed. In addition, a block copolymer featuring the biological relevant biotin moiety was prepared via NITEC at 974 nm, demonstrating the suitability of the approach for applications in the field of biology. Biotin was found to retain bioactivity after being exposed to the NITEC reaction conditions. The efficient penetration ability of the NIR irradiation applied was verified by 'through tissue' conjugation experiments. After the NITEC reaction was demonstrated to be a powerful ligation tool in solution, the concept was employed for the modification of surfaces in a λ-orthogonal approach. The selective ability of the pyrene tetrazole and an UV-active diaryl tetrazole to undergo independent NITEC reactions at 410 -420 nm, and 320 nm respectively, was demonstrated in solution. Importantly, the UV-active tetrazole remains unreacted if exposed to visible light, even for prolonged irradiation times. Subsequently, a surface grafted with pyrene functional tetrazole and UV-active tetrazole was prepared and utilized for formation of advanced patterned surfaces.

show abstract

Spin Probes and Spin Labels

Smirnova

Voinov

Smirnov

2009

Encyclopedia of Analytical Chemistry

View full text Add to dashboard Cite

Electron paramagnetic resonance (EPR) spectroscopy is a versatile and exceptionally sensitive technique for detecting and studying molecular systems possessing unpaired electronic spins. It finds substantial use in characterizing paramagnetic metal ions and organic free radicals. The scope of EPR applications in analytical chemistry can be expanded significantly by means of spin labels and spin probes — exogenous EPR‐active species that are introduced solely for the purpose of gaining information on the system under study. These labels and probes are persistent free radicals or paramagnetic metal ions designed to be partitioned or attached to specific molecular sites. To be suitable for analytical applications, spin labels and probes should readily report on properties of interest, exhibit distinguishable from background EPR signals, and leave the system only minimally perturbed by their presence. In this article, we describe a series of spin labels and probes as well as the associated EPR methods that are tailored to specific analytical applications of EPR spectroscopy — from assessing local oxygen and proton concentration to profiling electrostatic properties of biopolymers and lipid bilayers. The primary focus is bioanalytical applications of spin label/probe methods, with an emphasis on the synergy between the rational design of spin‐bearing molecules using the tools of organic chemistry and desired analytical capabilities.

show abstract

The application of a novel profluorescent nitroxide to monitor thermo-oxidative degradation of polypropylene

Cited by 64 publications

References 26 publications

The First Example of an Azaphenalene Profluorescent Nitroxide

The First Example of an Azaphenalene Profluorescent Nitroxide

From UV to NIR light, photo-triggered 1,3 dipolar cycloadditions as a modern ligation method in solution and on surface

Spin Probes and Spin Labels

Contact Info

Product

Resources

About