A Comparative Study of the Degradability and Recyclability of Different Classes of Degradable Polyethylene

Al‐Malaika, S.; Chohan, S.; Coker, M.; Scott, Gerald; Arnaud, René; Dabin, Philippe; Fauve, A.; Lemaire, Jácques

doi:10.1080/10601329508010283

Cited by 22 publications

(19 citation statements)

References 10 publications

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“…It has been suggested that such changes in molecular weight [29][30][31] are due to the formation of cross-links, through the vinyl group, which competes with the chain scission at relatively early stage of the photolysis [32]. It was also shown [29] that there is also a good correlation between the reduction in molecular weight and the buildup of carbonyl-containing compounds as the main photoxidation products during accelerated UV exposure…”

Section: Polymers With In-chain Ketonesmentioning

confidence: 83%

“…The photodegradation behavior of commercially produced films of photolytic polymers has been examined under laboratory accelerated photoaging conditions at 60 C [29]. Figure 16.2 shows that exposure of the E-CO polymer (origin: Dupont) to light results in immediate and rapid photoxidation without an induction period and this is clearly seen to be associated with a very fast rate of reduction in its molar mass (MW drops from about 300,000 to 50,000-20,000) particularly at the early stages of photoxidation, followed by a much slower decrease to 6000-2000 on prolonged UV exposure well beyond polymer embrittlement [29].…”

Section: Polymers With In-chain Ketonesmentioning

confidence: 99%

“…Figure 16.2 shows that exposure of the E-CO polymer (origin: Dupont) to light results in immediate and rapid photoxidation without an induction period and this is clearly seen to be associated with a very fast rate of reduction in its molar mass (MW drops from about 300,000 to 50,000-20,000) particularly at the early stages of photoxidation, followed by a much slower decrease to 6000-2000 on prolonged UV exposure well beyond polymer embrittlement [29]. It has been suggested that such changes in molecular weight [29][30][31] are due to the formation of cross-links, through the vinyl group, which competes with the chain scission at relatively early stage of the photolysis [32]. It was also shown [29] that there is also a good correlation between the reduction in molecular weight and the buildup of carbonyl-containing compounds as the main photoxidation products during accelerated UV exposure…”

Section: Polymers With In-chain Ketonesmentioning

confidence: 99%

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Photodegradable Polymers

Al‐Malaika

Hewitt

Sheena

2010

Photochemistry and Photophysics of Polymer Materials

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Polymers are used in a wide range of fields either as replacement materials or for unique applications. Designing polymers for end-use target applications must take into account the entire life cycle of the product starting from raw materials to production, product lifetime(s), and waste. The environmental load engendered from such an activity cannot be overemphasized and efforts are currently being made to reduce the negative image and impact of polymers without undermining their usefulness and benefits to progress and society. The true impact of polymers on society, resources, and the environment is continually being reassessed and great strides have been made to address some of the issues and challenges relating to aspects of polymer durability and degradability.This chapter deals with the photochemistry of photodegradable polymers, primarily hydrocarbon based. The discussion will be limited to that of the initial abiotic Photochemistry and Photophysics of Polymer Materials, Edited by Norman S. Allen

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Section: Polymers With In-chain Ketonesmentioning

confidence: 83%

Section: Polymers With In-chain Ketonesmentioning

confidence: 99%

Section: Polymers With In-chain Ketonesmentioning

confidence: 99%

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Photodegradable Polymers

Al‐Malaika

Hewitt

Sheena

2010

Photochemistry and Photophysics of Polymer Materials

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“…In addition, in some ageing cases (see for instance [41,42] resulting from the partial conversion of carboxylic acids by sodium hypochlorite according to the following reaction [43].…”

Section: Ftir Analysismentioning

confidence: 99%

A kinetic model for predicting the oxidative degradation of additive free polyethylene in bleach desinfected water

Mikdam

Colin

Minard

et al. 2017

Polymer Degradation and Stability

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. A B S T R A C TThe chemical interactions between additive free PE and bleach were investigated by FTIR spectrophotometry and viscosimetry in molten state after immersion (for a maximum duration of one hundred days) in bleach solutions maintained at a temperature of 60°C, a free chlorine concentration of 100 ppm, and a pH = 4, 5 or 7. It was found that the polymer undergoes a severe oxidation from the earliest days of exposure in a superficial layer of about 50-100 μm thick, almost independent of the pH value. In this layer, oxidation leads to the formation and accumulation of various carbonyl products (mostly ketones and carboxylic acids) but also, after about 2-3 weeks of exposure, to a dramatic decrease in the average molar mass due to the large predominance of chain scissions over crosslinking. It was also found that the oxidation rate is maximum at pH = 5, and of the same order of magnitude at pH = 4 and 7. Based on the equilibrium diagram giving access to the relative predominance of the three main chemical species as a function of the pH value of the bleach solution, it was assumed that oxidation is initiated by radical species coming firstly from hypochlorous acid (ClOH) and secondarily from chlorine (Cl 2 ), given that hypochlorite ions (ClO − ) are totally insoluble into the PE matrix. In addition, for explaining the surprisingly large value of the oxidized layer thickness despite the high reactivity of the involved radicals, it was assumed that ClOH and Cl 2 do not decompose into radicals in the water phase, but migrate deeply into the PE matrix prior to dissociating into Cl% and HO% radicals and then, initiating a radical chain oxidation. The validity of the kinetic model derived from this scenario was successfully checked by comparing the numerical simulations with all the experimental data collected in this study. This model predicts the general trends of the oxidation kinetics and its dependence on the pH value, but also gives access to the transport properties of the chlorinated disinfectants and their radical species, and the rate constants of the radical attack.

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“…9 Additionally, if not controlled, photofragmentation, which increases litter, rather than photodegradation of these materials may occur. 10 Degradable polymers have been developed without antioxidant packages or with pro-oxidants that allow slow degradation over time. They present similar advantages and disadvantages to photodegradable polymers in their cost structure, performance properties, use of non-renewable resources, and the production of degradation products other than CO 2 and water such as ketones, branched alkenes, alcohols, and esters.…”

Section: Sustainable Polymer Optionsmentioning

confidence: 99%