Polyethylene hydroperoxide decomposition products

Lacoste, J.; Carlsson, D. J.; Falicki, S.; Wiles, D. M.

doi:10.1016/0141-3910(91)90125-b

Cited by 115 publications

(56 citation statements)

References 16 publications

(9 reference statements)

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“…However, the excimer fluorescence band of o-PFS shifts from (314 nm to 316 nm), and m-PFS excimer fluorescence band shows shift from (313 nm to 316 nm), and p-PFS excimer fluorescence band shows shift from (322 nm to 332 nm). It is more likely that this red shift occurs as result of photodegradation of the polymeric chains, and can be attributed to the formation of conjugated double bonds along the polymer chain during the photodegradation by hydrogen abstraction process (Lacoste, Carlson, Falicki, & Wiles, 1994). The fluorescence band shift of these isomers is in good agreement with that reported with irradiated polystyrene (David et al, 1978), and other poly (substituted styrene) films (Subramanian, 2002).…”

Section: Effect Of Uv-irradiation On Fluorescence Spectra Of Pure Andsupporting

confidence: 80%

UV-Irradiation Effect on the Photodegradation of Plasticized Poly (Ortho, Meta, and Para-Fluorostyrene) Isomers in Solid Films

Ani¹,

Anabtawi²

2012

IJC

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The photostability of thin films of poly (Fluorostyrene) isomers was studied by irradiation with UV-light, in presence of air at room temperature. The irradiated polymer films were exposed to different intervals of time and the degradation process was investigated with absorption, fluorescence and FT-IR spectroscopic methods. The influence of phthalate and terephthalate plasticizers on photo-oxidative degradation was also investigated. Blending with these plasticizers was found to decrease the stability of the irradiated polymers. The same observation was noticed in the photodegradation of other substituted polystyrenes films. The intensity of absorption was also found to increase with time of irradiation and in the intensity of a new absorption band at longer wavelength. In addition the formation on new fluorescence band at longer wavelength for the irradiated film is an evidence of photodegradation of the irradiated polymer films. The FT-IR spectra of irradiated polymers and for blended polymer films with phthalates and terephthalate, showed an increase in the absorption bands of these isomers indicating the possibility of degradation. The mechanism of photodegradation of these isomers was found to be similar to that of polystyrene. The order of photostability of these isomers was found that poly (p-fluorostyrene) is the most stable isomer and, poly (o-fluorostyrene) is the lowest stable isomer towards irradiation effect.

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Section: Effect Of Uv-irradiation On Fluorescence Spectra Of Pure Andsupporting

confidence: 80%

UV-Irradiation Effect on the Photodegradation of Plasticized Poly (Ortho, Meta, and Para-Fluorostyrene) Isomers in Solid Films

Ani¹,

Anabtawi²

2012

IJC

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“…Irradiation of the PMS film at different exposure time was accompanied by the gradual quenching in the intensity of the excimer band, as well as a small red shift in the excimer fluorescence band (313 -315 nm). It is more likely that this red shift occurs as result of photodegradation of the polymeric chains, and can be attributed to the formation of conjugated double bonds along the polymer chain during the photodegradation by hy- drogen abstraction process [41] [43].…”

Section: Effect Of Uv-irradiation Time On Fluorescence Spectra Of Purmentioning

confidence: 99%

Irradiation Effect on Photodegradation of Pure and Plasticized Poly (4-Methylstyrene) in Solid Films

Safi¹,

Mouamin²,

Sieadi³

et al. 2014

MSA

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The photodegradation of irradiated thin films of poly (para-methylstyrene) with 265 nm radiations in the presence of airand as a function of irradiation time has been studied using UV-VIS, fluorescence and FT-IR Spectroscopic techniques. The influence of phthalate and terephthalate plasticizers on stability of poly (para-methylstyrene) towards irradiations was also investigated. Blending with phthalate plasticizers was found to cause a higher efficiency of photodegradation than that obtained in doping with terephthalate plasticizers. The intensity of absorption was also found to increase with time of irradiation and in change in the shape of the spectra at longer wavelength, thus indicating a possibility of photodegradation of polymer chains. The analysis of the FT-IR spectra of the irradiated and non-irradiated samples, shows a predominant absorption associated with carbonyl compounds with 1740 cm −1 . In addition, the observed increase in the intensities of the carbonyl and hydroxyl regions of the FT-IR spectra, have provided an evidence for the photodegradation as well as photo-oxidation of polymeric chains. The presence of the plasticizer in the polymer backbone was found to accelerate the photodegradation of polymeric chains.

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“…For the unstabilized LDPE samples (Fig-3) [25,26,27,28]. These unsaturations are also visible to 1641 cm -1 .…”

Section: Attenuated Total Reflection Fourier Transform Infrared Spectmentioning

confidence: 84%

“…For the stabilized LDPE samples (Fig-2) we observe: -Two peaks with a very weak intensity: one at 888 cm -1 is assigned to vinylidene >C=CH 2 groups and the other at 831 cm -1 corresponding to the vinyl R 2 C=CHR groups [25,26,27,28]. These unsaturations are also visible to 1635 cm are attributed to the stretching vibration of C-O bond, this latter belongs to ether R-O-R and alcohol RCH 2 -OH groups [19,29].…”

Section: Attenuated Total Reflection Fourier Transform Infrared Spectmentioning

confidence: 99%

Natural Ageing of Stabilized and Unustabilized Ldpe Films Used as Greenhouses Covering Materrials: Atr-Ftir and Sem Analysis

.¹

2015

IJRET

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This article focuses on the study of both stabilized and unstabilized low-density polyethylene films aged under natural weathering in the middle of Morocco (Sidi Kacem city). The study was undertaken on three samples for each LDPE films: a new sample taken as reference; another exposed to outdoor weathering for one year; and a sample exposed for two years. The outdoor exposure effects were followed by analysis of the total reflection Fourier transform infrared spectroscopy (ATR-FTIR). This technique provides information on the main chemical functions and evaluates the internal causes of natural ageing of our samples. The infrared spectra show the formation of hydroperoxides -O-OH, carbonyls >C=O, aliphatic esters R-(CO)-O-R, ether R-O-R, vinyl C=C, vinylidene >C=CH 2 and trans-vinylene RHC=CRH in the amorphous regions. These compounds lead to initiate the mechanism of photo-oxidation of the unstabilized LDPE samples. Therefore, the increase in the formation of oxidation products into the aged samples (LDPEUS) indicates an accelerated degradation of these latter on climatic factors (UV, O2, humidity, rain ...). The UV stabilizer (free radicals scavengers) added to the formulation of LDPE films can delay the attack of the amorphous phase and prevent the formation of compounds that can cause and accelerate photo-oxidation. The results obtained by the infrared have been confirmed by observing the morphology of the samples with scanning electron microscopy technology (SEM).

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Polyethylene hydroperoxide decomposition products

Cited by 115 publications

References 16 publications

UV-Irradiation Effect on the Photodegradation of Plasticized Poly (Ortho, Meta, and Para-Fluorostyrene) Isomers in Solid Films

UV-Irradiation Effect on the Photodegradation of Plasticized Poly (Ortho, Meta, and Para-Fluorostyrene) Isomers in Solid Films

Irradiation Effect on Photodegradation of Pure and Plasticized Poly (4-Methylstyrene) in Solid Films

Natural Ageing of Stabilized and Unustabilized Ldpe Films Used as Greenhouses Covering Materrials: Atr-Ftir and Sem Analysis

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