Thermal oxidation of polyethylene in compost environment

Weiland, Michèle; David, Christiane

doi:10.1016/0141-3910(94)90207-0

Cited by 23 publications

(4 citation statements)

References 14 publications

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“…UV-treated and untreated samples exposed to SF1 exhibited largest reduction in T g . Similar reduction in T g due to degradation was observed by many researchers. ,, In contrary to the above observations, an increase in glass transition temperature was observed for the thermally treated when compared to untreated polycarbonate. According to the Flory’s theory, the T g of a polymer depends on the electronic interactions between the macromolecules and the free volume surrounding them.…”

Section: Resultssupporting

confidence: 89%

Biodegradation of Physicochemically Treated Polycarbonate by Fungi

Artham

Doble

2009

Biomacromolecules

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Two fungal strains isolated from soil and a commercial white-rot fungus, Phanerochaete chrysosporium NCIM 1170 (SF2), were tested for biodegradation of untreated, UV-, and thermal-treated bisphenol A polycarbonate (PC). The isolated strains based on 18S rDNA analysis were characterized as Engyodontium album MTP091 (SF1) and Pencillium spp. MTP093 (SF3). About 5.4% weight loss and 40% reduction in M(n) were observed for UV-treated polycarbonate in one year with SF2 strain. An increase in surface energy and oxygen content and a reduction in methyl index indicated oxidation of PC during this period. PC exposed to the SF1 strain showed a 15 degrees C decrease in glass transition temperature, indicating an increase in the number of chain ends and, hence, an increase in the free volume of polymer. No bisphenol A, the monomer of PC, was detected during the study. NMR and FTIR spectra showed the formation of methyl groups due to pretreatments. EDAX analysis exhibited surface oxidation of the PC. The current study advocates that biodegradation of PC can be enhanced by pretreatments.

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Section: Resultssupporting

confidence: 89%

Biodegradation of Physicochemically Treated Polycarbonate by Fungi

Artham

Doble

2009

Biomacromolecules

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“…Photooxidation reduces the molecular weight of the polymer and triggers a great variety of physical and chemical changes, favoring the production of carbonyl groups 2, 3. The thermal treatment has been used4 to make polyethylene more susceptible to biodegradation; at temperatures higher than the melting point the thermal treatment decreases the fusion heat and increases the carbonyl content 5…”

Section: Introductionmentioning

confidence: 99%

Biodegradation of physicochemically treated LDPE by a consortium of filamentous fungi

Manzur

Limón-González

Favela‐Torres

2004

J of Applied Polymer Sci

104

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Samples of low density polyethylene previously subjected to physicochemical treatments-thermal treatment (TT) at 105 and 150°C or accelerated aging treatment (AAT)-were subjected to biodegradation by a consortium of four fungi during 9 months. Morphological, structural, and surface changes and mineralization were evaluated. TT samples showed decreases in the onset melting temperature (T o ), melting point (T m ), relative crystallinity (⌽), and mean crystallite size (L 110 ). The degradation products in all treated samples were carbonyl and double bonds groups. The biological treatment (BT) affected the properties of all treated samples. T o at 3 months decreased with respect to sample at 0 months; the changes were higher in TT samples; the samples then remained without significant changes. Increases in ⌽ were observed in TT samples within a 3-month BT, after which reductions occurred. After a 9-month BT, increases in L 110 were registered in all samples (up to 2.6 nm). The highest mineralization value (3.26%) was obtained with the AAT. The reported changes suggested that the fungi mainly digest the amorphous phase of polyethylene in the first stage of the experiment, but later they also digest small crystals. Superficial growth of microorganisms occurred, and penetration of hyphae was observed in most oxidized samples.

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“…In another study, LDPE films containing Co-acetylacetone, Co-stearate, and Mn-stearate degraded rapidly in dry oven air at 60ЊC, while the degradation was much slower in compost. 23 After 8 weeks in the compost no further degradation was seen in the films during 5 days in an oven at 60ЊC. When the transition metal contents of LDPE films was measured by using X-ray fluorescence (XRF) …”

Section: Resultsmentioning

confidence: 99%

“…(a) the methanol fraction with carboxylic stearate remained in the films, but was somehow acids, and (b) the acidic methanol fraction with dicardeactivated during the composting and could no boxylic acids and ketoacids. The numbered peaks are longer initiate the degradation in dry oven, as obidentified in Table II. served by Weiland et al 23 were identified as homologous series of mono-and dicarboxylic acids. In addition a homologous serie…”

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confidence: 99%

Susceptibility of starch-filled and starch-based LDPE to oxygen in water and air

Hakkarainen

Albertsson

Karlsson

1997

J. Appl. Polym. Sci.

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ABSTRACT:The susceptibility of starch-filled and starch-based polyethylenes to oxygen in water and air was analyzed and compared. LDPE containing 7.7% starch and a prooxidant formulation in the form of masterbatch (LDPE-MB) was compared to pure LDPE, LDPE with 7.7% starch (LDPE-starch), and a blend with 70% starch and 30% ethylene maleic anhydride (starch-EMA). Thermal ageing at 80ЊC in air and water was followed by monitoring the molecular weight changes, the formation of carbonyl groups, and degradation products by SEC, FTIR, and GC-MS. It was demonstrated that LDPE-MB was the most susceptible material to degradation in both environments, although the degradation was faster in air than in water. The slower degradation in water is explained by a deactivation or leaching out of the pro-oxidant during the aging. The degradation of pure LDPE and starch-EMA is faster in water than in air. LDPEstarch was the only material that did not degrade during 11 weeks in water at 80ЊC. The addition of starch to LDPE made this material even more stable than pure LDPE to aging in water. The molecular weight distribution of LDPE-MB narrowed during aging in air. In water, on the other hand, the MWD of LDPE-MB, LDPE, and LDPEstarch broadened. The lower oxygen concentration in water increases the probability for molecular enlargement reactions in comparison to the case in air. Mono-and dicarboxylic acids were the major products identified in both environments. Ketoacids were formed in both air and water, but ketones and hydrocarbons were only identified after aging in air. Either these products are not formed or they remain in the polymer matrix rather than migrate out into the water. Lactic acid and 2-furancarboxaldehyde were only identified in the starch-EMA material degraded in water at 80ЊC. LDPE, LDPEstarch, and starch-EMA did not form any degradation products during 11 weeks at 80ЊC in air in agreement with the neglible molecular weight changes observed.

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Thermal oxidation of polyethylene in compost environment

Cited by 23 publications

References 14 publications

Biodegradation of Physicochemically Treated Polycarbonate by Fungi

Biodegradation of Physicochemically Treated Polycarbonate by Fungi

Biodegradation of physicochemically treated LDPE by a consortium of filamentous fungi

Susceptibility of starch-filled and starch-based LDPE to oxygen in water and air

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