Protection in radiolysis of n-hexadecane—2. Radiolysis of n-hexadecane in the presence of additives

Soebianto, Yanti S.; Katsumura, Yosuke; Ishigure, Kenkichi; Kubo, Junichi; Koizumi, Takeo

doi:10.1016/1359-0197(92)90209-x

Cited by 8 publications

(11 citation statements)

References 19 publications

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“…Similar phenomena were observed before [13]. (2) Protection effects by additives (2,31 In the presence of aromatic additives the following results were observed; (i) reduction of Hz evolution (Fig. 3), (ii) reduction of the solvent degradation ( Fig.…”

Section: Introductionsupporting

confidence: 78%

Radiation induced degradation of polymers ‐an approach by using liquid paraffins as a model system

Katsumura¹

1997

Angew. Makromol. Chem.

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Paraffins, n-hexadecane and squalane, were employ_ed as a model of polymers and radiation induced reactions in the polymers have been simulated. After vacuum irradiation, products were identified and their yields were determined by a variety of techniques. In the presence of the aromatic additives, the reduction of the degradation, so called protection effect, was clearly observed. Both energy and charge transfer play important roles in the protection effect. The same system was adapted to the irradiation under aerated condition in order to clan'fy the radiation induced oxidation. Furthermore, corresponding experiments using polypropylene were also performed and validity of the model system and phase effect were discussed. On the basis of the above results, it was revealed that the model experiment is valuable to understand the radiation induced reactions in polymers, especially amorphous phase of the polymers.Recently, the same model system has been extended to the thermal degradation at the temperamre ranges of 300 -400'C. When radiation was introduced, both a significant acceleration of the degradation and an enhancement of H? evolution were clearly observed. This is suggesting a potential application of radiations to the degradation of polymers at elevated temperatures.induced reactions in polymers were simulated. The protection effect was also investigated. Ln order to confirm the experimental findings observed in the model system, similar experiment was done in polypropylene. It was revealed that this approach is very useful and powerful to understand the radiation induced degradation processes in polymers [ 1-51.Similar system was extended to the experiment on radiation thermal cracking in order to evaluate whether radiation would be helpful to the thermal cracking and, further, applicable to the general thcrmal degradation processes. It was found that, under a certain condition, irradiation accelerates the thermal degradation an order of 100 times [6-61.i n the present experiment, liquid paraffins were chosen as a polymer model, in whichPaper presented at

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Section: Introductionsupporting

confidence: 78%

Radiation induced degradation of polymers ‐an approach by using liquid paraffins as a model system

Katsumura¹

1997

Angew. Makromol. Chem.

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“…The relative increase in molecular hydrogen with increasing LET is much greater for PS than for the other polymers examined here. The presence of functional groups such as those in PMMA and PS may lower the yield of CH bond breakage and thereby H 2 formation by siphoning some of the initial energy deposited in the polymer 36. It is also possible that H atoms are formed with the same yields for all the polymers but that additional reactions are responsible for their disappearance with PS and, to a lesser extent, with PMMA.…”

Section: Resultsmentioning

confidence: 99%

Hydrogen production in ?-ray and helium-ion radiolysis of polyethylene, polypropylene, poly(methyl-methacrylate), and polystyrene

Chang

LaVerne

2000

J. Polym. Sci. A Polym. Chem.

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“…Similar observations were already described for a different crown ether (dicyclohexano 18 crown-6), that exhibited weak radiolytic degradation in toluene compared with that in the aliphatic solvents octanol or cyclohexane. 31,32 Table 2 presents also the impact of solvent on calixarene stability in the form of G-values. These G-values are calculated based on the loss of calixarene at the end of exposure (expressed as molecules lost) and the total energy exposure (expressed in eV) of the entire volume of solution.…”

Section: Aromatic Substitutionmentioning

confidence: 99%

High‐performance liquid chromatography with electrospray ionisation mass spectrometry and diode array detection in the identification and quantification of the degradation products of calix[4]arene crown‐6 under radiolysis

Lamouroux

Aychet

Lelièvre

et al. 2004

Rapid Comm Mass Spectrometry

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The extraction of 135Cs from high-activity liquid waste, arising from reprocessing of spent nuclear fuel, can be achieved by using calix[4]arene crown-6 compounds. The radiolytic degradation of di(n-octyloxy)calix[4]arene crown-6 (octMC6), in aliphatic or aromatic solvent in contact with 3 M nitric acid, was studied by high-performance liquid chromatography directly coupled to electrospray ionisation mass spectrometry (LC/ESI-MS). More than 50 distinct degradation products were observed, and about 30 of these were identified. These compounds can be assigned to three categories, namely, products of reactions involving radical cleavage or addition, of oxidation reactions, or of aromatic substitution reactions. The major product, corresponding to substitution by an NO2 group, was quantified by external standard calibration using a purified synthetic sample. Despite the observation of all these degradation compounds, octMC6 appears to be remarkably stable under these drastic conditions, combining hydrolysis (HNO(3) 3 M) and an extreme exposure to radiolysis (10(6) Gy). Less than 35% degradation of octMC6 was observed in aromatic solvent under these conditions.

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Protection in radiolysis of n-hexadecane—2. Radiolysis of n-hexadecane in the presence of additives

Cited by 8 publications

References 19 publications

Radiation induced degradation of polymers ‐an approach by using liquid paraffins as a model system

Radiation induced degradation of polymers ‐an approach by using liquid paraffins as a model system

Hydrogen production in ?-ray and helium-ion radiolysis of polyethylene, polypropylene, poly(methyl-methacrylate), and polystyrene

High‐performance liquid chromatography with electrospray ionisation mass spectrometry and diode array detection in the identification and quantification of the degradation products of calix[4]arene crown‐6 under radiolysis

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