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| Deroine, Morgan; Cesar, Guy; Le Duigou, Antoine; Davies, Peter; Bruzaud, Stephane. |
| In this study, natural degradation and biodegradation of poly(3-hydroxybuyrate-co-3-hydroxyvalerate) (PHBV) films were followed in different marine environments. First of all, ageing of PHBV films was investigated in natural seawater for 180 days and degradation was followed by means of weight loss measurements, scanning electron microscopy (SEM), differential scanning calorimetry and steric exclusion chromatography. In a second part, biodegradation tests were performed on PHBV powder, by following carbon dioxide (CO2) release(,) to highlight the PHBV bioassimilation of marine microorganisms. Three different marine environments were considered for biodegradation tests: a solid inoculum with foreshore sand, a solid-liquid inoculum with sand and seawater and... |
| Tipo: Text |
Palavras-chave: PHBV; Natural ageing; Degradation; Biodegradation; Seawater. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00296/40735/42020.pdf |
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| Deroine, Morgan; Le Duigou, Antoine; Corre, Yves-marie; Le Gac, Pierre-yves; Davies, Peter; Cesar, Guy; Bruzaud, Stephane. |
| The aim of this study is to establish a baseline for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) lifetime prediction in a marine environment, by means of mechanical and physico-chemical characterization of specimens immersed in continuously renewed and filtered natural seawater in the laboratory at different temperatures (4, 25 and 40°C). Samples were also aged at sea in Lorient harbour in order to compare laboratory and natural degradation mechanisms and kinetics. Due to its morphology, hydrolysis of PHBV in natural seawater is quite slow, and samples were observed to undergo preferentially an enzymatic surface degradation. Increasing the aging temperature in the laboratory promotes the water uptake and causes hydrolysis. As two degradation... |
| Tipo: Text |
Palavras-chave: Poly(3-hydroxybutyrate-co-3-hydroxyvalerate); Accelerated ageing; Hydrothermal degradation; Seawater. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00188/29972/28425.pdf |
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| Deroine, Morgan; Le Duigou, Antoine; Corre, Yves-marie; Le Gac, Pierre-yves; Davies, Peter; Cesar, Guy; Bruzaud, Stephane. |
| Accelerated ageing was performed in distilled water at different temperatures (25, 30, 40 and 50°C) on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), which is a biodegradable biopolymer, in order to estimate its lifetime in aqueous environment. In a first part, degradation mechanisms were followed by gravimetry, tensile tests and steric exclusion chromatography. Both immersion and relative humidity have been examined. In a second part, the strain at break was used as an indicator for lifetime prediction with an Arrhenius extrapolation. The study revealed the presence of only one irreversible degradation mechanism, i.e. hydrolytic degradation, which is temperature dependant. So, within the approach assumptions, the lifetime in distilled water of PHBV... |
| Tipo: Text |
Palavras-chave: Poly(3-hydroxybutyrate-co-3-hydroxyvalerate); Accelerated ageing; Hydrothermal degradation; Lifetime prediction. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00203/31396/29785.pdf |
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| Deroine, Morgan; Le Duigou, Antoine; Corre, Yves-marie; Le Gac, Pierre-yves; Davies, Peter; Cesar, Guy; Bruzaud, Stephane. |
| Pollution of nature by plastics is a major environmental problem and the challenge for the future is to manage the lifetime of polymers better. The aim of this study is to establish a baseline on degradation mechanism and degradation kinetics for lifetime prediction of polylactide (PLA) in a marine environment. The ageing of PLA was accelerated by raising temperature in distilled water, filtered and renewed seawater and natural seawater. Samples were immersed in distilled water for six months at different temperatures (25, 30, 40 and 50°C) in order to evaluate the influence of temperature on PLA degradation kinetics and to predict lifetime. Then, samples were immersed in seawater both in the laboratory and at sea, in order to compare the effects of... |
| Tipo: Text |
Palavras-chave: PLA; Accelerated ageing; Hydrothermal ageing; Degradation. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00173/28376/26689.pdf |
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| Kedzierski, Mikael; Villain, Jonathan; Falcou-prefol, Mathilde; Kerros, Marie Emmanuelle; Henry, Maryvonne; Pedrotti, Maria Luiza; Bruzaud, Stephane. |
| The study of microplastic pollution involves multidisciplinary analyses on a large number of microplastics. Therefore, providing an overview of plastic pollution is time consuming and, despite high throughput analyses, remains a major challenge. The objective of this study is to propose a protocol to determine how many microplastics must be analyzed to give a representative view of the particle size distribution and chemical nature, and calculate the associated margin error. Based on microplastic data from Tara Mediterranean campaign, this approach is explained through different examples. In this particular case, the results show that only 3% of the collected microplastics need to be analyzed to give a precise view on the scale of the North West... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00481/59305/62058.pdf |
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