Effect of extrusion and photo-oxidation on polyethylene/clay nanocomposites

Dintcheva, Nadka Tzankova; Al‐Malaika, S.; Mantia, Francesco Paolo La

doi:10.1016/j.polymdegradstab.2009.04.012

Cited by 94 publications

(85 citation statements)

References 49 publications

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“…As regards the elastic modulus, the addition of PPgMA leads to a significant reduction of the rigidity of the material (higher upon increasing the MA content), in agreement with previous results on similar systems [17]. The behavior is completely different as far as the nanocomposites are concerned: the elastic modulus keeps practically unchanged, and some reductions (however, not higher than 5%) are experienced only in the S31-filled nanocomposite at higher PPgMA content.…”

Section: Resultssupporting

confidence: 89%

“…These phenomena have been reported for several kinds of polymer used and were mainly attributed to a reduction of the photo-oxidation induction time [9][10][11][12][13][14][15][16][17]. This, in turn, was attributed to several factors, such as the presence of iron ions catalyzing the photo-oxidation process [9,10], the formation of catalytic acidic sites or radicals following the decomposition of the organo-modifier (involving both the alkyl chain and the ammonium ions) [10][11][12]17]. As regards the nanocomposites containing nanosized calcium carbonate, it was found [18] that the photo-oxidation rate increases in comparison to the pristine polymer matrix, and it was proposed that this might be attributed to several causes (nucleation phenomena, catalytic effects, presence of impurities or light sensitizers).…”

mentioning

confidence: 64%

“…With particular concern to the CL15A nanocomposite, the subtended area is significantly smaller, as already shown by the CI data, suggesting that the presence of PPgMA actually reduces the photo-oxidation products formation in the carbonyl region. This can be explained by considering that the acid sites formed onto the clay platelets during photooxidation (due to the Hoffmann elimination of the organomodifier [17]) are partially hindered by the presence of the maleic anhydride which creates a physical barrier. However, the results are even more interesting when the S31 nanocomposite is taken into account.…”

Section: Resultsmentioning

confidence: 99%

“…It is also known from the literature [20] that this general purpose PP usually contains small amounts of phenolic primary antioxidants and phosphite secondary antioxidants. However, it is known from the Literature that they are able to protect against thermal-oxidation during the processing [9,11,14,17], but they have only an indirect influence on the photo-oxidation behaviour (for instance, by interfering with the formation of double bonds), which could be seen only as far as the final conditions are concerned, while the mechanisms and paths are not altered; furthermore, all of the systems prepared and investigated here contain practically the same amount of antioxidants, therefore their presence does not influence the comparisons. The nanosized fillers were a precipitated calcium carbonate, supplied by Solvay (Belgium) under the commercial name of Socal ® 31 (in the following indicated as S31), with a calcite rhombohedral crystal structure, cube-like crystal shape and a mean particle diameter 50-100 nm [21], and a montmorillonite clay produced by Southern Clay Products (USA) and commercialized as Cloisite ® 15A (further indicated as CL15A; modified with dimethyldihydrogenated tallow-quaternary ammonium chloride quaternary surfactant; quaternary concentration = 12 meq·(100 g) -1 clay; d 001 = 3.15 nm; density = 1.66 g·cm -3 ).…”

Section: Experimental 21 Materialsmentioning

confidence: 99%

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Accelerated weathering of PP based nanocomposites: Effect of the presence of maleic anhydryde grafted polypropylene

Morreale¹,

Dintcheva²,

Mantia³

2013

Express Polym. Lett.

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The use of nanometric-scale sized fillers for the preparation of thermoplastic polymer composites is of topical interest in the academia, because of the significant improvements achievable in terms of technological properties, such as the elastic modulus, the tensile strength, the barrier properties, the flexural modulus [1][2][3][4][5][6][7][8]. These enhancements are promising and attracting also the interest from industrial world, in sight of several applications which could benefit from them. On the other hand, it is known [3] that polymer based nanocomposites have been struggling to conquer mainstream volume market shares, and this can be attributed to some weaknesses. One of these is represented by their environmental stability, especially when outdoor applications (i.e. furnishing, building, packaging, automotive) are concerned. It is known from the literature that polymer/silicate nanocomposites can show significant effects due to photo-oxidation (in particular, higher photo-oxidation rates and thus reduction of the mechanical prop- Abstract. Polymer nanocomposites are currently a topic of great interest. The increasing importance they are gaining also in the standpoint of industrial applications, is giving concerns regarding their environmental stability and, in general, their behaviour in outdoor applications, under direct solar irradiation. Papers available in the literature have highlighted the different influences of different nanosized fillers, in particular clay-based nanofillers; however, few data are available regarding other nanosized fillers. Furthermore, the research on polymer nanocomposites has clearly pointed out that the use of compatibilizers is required to improve the mechanical performance and the dispersion of polar fillers inside apolar polymer matrices, especially when complex mechanisms such as intercalation and exfoliation, typical of clay-filled nanocomposites, are involved. In this work, the photo-oxidation behaviour of polypropylene/clay and polypropylene/calcium carbonate nanocomposites containing different amounts of maleic anhydride grafted polypropylene (PPgMA) and subjected to accelerated weathering, was investigated. The results showed significant differences between the two nanofillers and different degradation behaviours in presence of the compatibilizer. In particular, PPgMA modified the dispersion of the nanofillers but, on the other hand, higher amounts proved to lead to the formation of some heterogeneities. Furthermore, PPgMA proved to positively affect the photo-oxidation behaviour by decreasing the rate of formation of the degradation products.

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Section: Resultssupporting

confidence: 89%

mentioning

confidence: 64%

Section: Resultsmentioning

confidence: 99%

Section: Experimental 21 Materialsmentioning

confidence: 99%

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Accelerated weathering of PP based nanocomposites: Effect of the presence of maleic anhydryde grafted polypropylene

Morreale¹,

Dintcheva²,

Mantia³

2013

Express Polym. Lett.

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“…Cabe resaltar que el área relativa de esta banda aumentó conforme avanzó el tiempo de exposición. Estos resultados son consistentes con literatura científica relacionada con el mecanismo de degradación del PE (Day et al 1997, Dintcheva et al 2009, Ojeda et al 2011, Dintcheva et al 2010.…”

Section: Resultados Y Discusiónunclassified

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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Stabilization of Polymers

Al‐Malaika

Sheena

2017

Encyclopedia of Polymer Science and Technology

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This review covers the fundamental aspects of polymer stabilization with emphasis on the underlying mechanisms of oxidative degradation of polymers, and the many factors that affect their stability and durability. The basic mechanisms of antioxidant action in polymer stabilization and the effects of chemical and physical factors that impact performance are presented. The different classes of antioxidants are discussed with specific examples. Recent progress made in several areas of stabilization targeted at improving the stability and durability of polymers is highlighted, for example, graftable and macromolecular antioxidants, bio‐based (natural/biological) antioxidants, polymer nanocomposites, photovoltaics, fuel cells and orthopedic implants.

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Effect of extrusion and photo-oxidation on polyethylene/clay nanocomposites

Cited by 94 publications

References 49 publications

Accelerated weathering of PP based nanocomposites: Effect of the presence of maleic anhydryde grafted polypropylene

Accelerated weathering of PP based nanocomposites: Effect of the presence of maleic anhydryde grafted polypropylene

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

Stabilization of Polymers

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