Influence of the repeated extrusion on the degradation of polyethylene. Structural changes in low density polyethylene

Dostál, Jiřı́; Kašpárková, Věra; Zatloukal, Martin; Muras, J.; Šimek, Lubomı́r

doi:10.1016/j.eurpolymj.2008.05.028

Cited by 49 publications

(49 citation statements)

References 18 publications

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“…Besides mechanical, also rheological properties are changed [9,10,11]. This has direct effect on the processability and needs to be considered during the following technological processes.…”

Section: Introductionmentioning

confidence: 98%

Processability and mechanical properties of extensively recycled high density polyethylene

Oblak

González-Gutiérrez

Zupančič

et al. 2015

Polymer Degradation and Stability

151

120

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Section: Introductionmentioning

confidence: 98%

Processability and mechanical properties of extensively recycled high density polyethylene

Oblak

González-Gutiérrez

Zupančič

et al. 2015

Polymer Degradation and Stability

151

120

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“…Uno de los polímeros sintéticos más utilizados a nivel mundial, es el polietileno (Dostál et al 2008), que presenta una buena resistencia química, es inodoro y no es tóxico. Sin embargo, es conocido por su alta resistencia a la degradación .…”

Section: Introductionunclassified

Degradación Acelerada De Películas De Polietileno Con Quitosano Compatibilizadas Con Anhídrido Maléico

Félix

Castillo

Castillo‐Ortega

et al. 2017

Rev. Int. Contam. Ambie.

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Palabras clave: extrusión, propiedades mecánicas, espectroscopía de infrarrojo, degradación en tierra RESUMEN La utilización de polímeros sintéticos como materia prima para empaques desechables genera altos volúmenes de contaminantes persistentes en el ambiente. Una manera de resolver el problema del acumulamiento de plásticos, es la producción de materiales poliméricos biodegradables. En este trabajo se presenta la preparación y pruebas de degradación acelerada de películas preparadas a partir de mezclas de polietileno lineal de baja densidad con quitosano, utilizando anhídrido maléico como compatibilizante. Las películas de polietileno con un 15 % de quitosano perdieron 40 % del valor inicial de resistencia a la tensión después de 360 h de degradación acelerada. En contraste con el 20 % de pérdida que presentó la película de polietileno puro durante el mismo periodo. Las películas con quitosano, además, redujeron 13 % de su peso después de estar bajo tierra de vivero durante 180 días, un valor considerablemente mayor que el 0.05 % que presentó la película de polietileno. La presencia de anhídrido maléico como compatibilizante favoreció un ligero aumento en la degradación de las películas de polietileno con quitosano.Key words: extrusion, mechanical analysis, infrared spectroscopy, degradation in soil ABSTRACTThe use of synthetic polymers as material for the production of disposable packaging, generates high volumes of persistent environmental pollutants. One way to solve the problem of the accumulation of plastics is the production of biodegradable polymeric materials. This work presents the preparation and testing of the degradation capability of films prepared from blends of linear low density polyethylene with chitosan, using maleic anhydride as a compatibilizer. Polyethylene films with 15 % chitosan, lost 40 % of the initial values of tensile strength after 360 h of accelerated degradation, in contrast Rev. Int. Contam. Ambie. 33 (Especial sobre Ingeniería Ambiental. Universidad Estatal de

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“…This group has its concentration increased with temperature as a result of and increase in kinetic formation of it: the heat provided increases the oxygen reaction rate with macroradicals [4][5][6][7][8][9][10][11][12][13][14][15][16][17] . On the other hand, number of extrusions yields more alkyl radicals to react with oxygen.…”

Section: Parameters Influence On Transvinylene Concentrationmentioning

confidence: 99%

“…Pinheiro, Chinelatto and Canevarolo [4,5] observed the same behavior for HDPE during multiple extrusions in twin screw extruder and internal mixer processing. Dostál et al [17] suggested that the predominant mechanism of LDPE degradation during multiple extrusions is the chain scission in the early processing, followed by chain branching due to macroradicals recombination in the later stages. Moss and Zweifel [9] studied the degradation of HDPE under multiple extrusions in a single screw extruder and observed that the Phillips' HDPE type showed an increase in molecular weight, whereas reduction was observed for the Ziegler-Natta's type.…”

Section: Introductionmentioning

confidence: 99%

Influence of Reprocessing in the formation of functional groups during low density polyethylene aging

et al. 2012

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Abstract:In recent years, the interest in polymer recycling has increased. However, in every reprocessing step the material undergoes shear stress and is affected by temperature and oxygen. The aim of this paper is to investigate the influence of multiple extrusion in the generation of functional groups, namely hydroperoxide, carbonyl, and transvinylene. Low density polyethylene was reprocessed three times in a single screw extruder. In each recycling step hot pressed films were prepared. These films were submitted to a heat treatment in an oven with air circulation and renovation to proceed with aging tests at different times and temperatures. The results obtained showed that all functional groups had their concentration increased with the increase in number of reprocessing, the aging time and temperature of the heat treatment. The factorial design was applied to verify the influence of these parameters. All the parameters had significant effects, since their regression coefficients had the same order of magnitude, with the most influential parameter being the aging temperature, followed by the aging time and number of extrusions. Most of the interactions were influential, indicating that the formation of functional groups depends upon their interaction, and not only on their isolated effects.

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Influence of the repeated extrusion on the degradation of polyethylene. Structural changes in low density polyethylene

Cited by 49 publications

References 18 publications

Processability and mechanical properties of extensively recycled high density polyethylene

Processability and mechanical properties of extensively recycled high density polyethylene

Degradación Acelerada De Películas De Polietileno Con Quitosano Compatibilizadas Con Anhídrido Maléico

Influence of Reprocessing in the formation of functional groups during low density polyethylene aging

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