Etude de mélanges de polyéthyléne et de polystyrène par diffraction de rayons X et par densimétrie

Lahrouni, A.; Arman, J.

doi:10.1016/0014-3057(94)00187-1

Cited by 3 publications

(5 citation statements)

References 11 publications

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“…Since DSC measurements showed that the crystallinity of the 50% PS : 50% PE blends from different processes was almost equivalent (about 51%), these data suggest that there are voids inside the extruded blends. Lahrouni 26 also has attributed the difference between the measured and the calculated density to the presence of voids in PS/PE blends. Shrinkage during PE crystallization is about 10%.…”

Section: Densitymentioning

confidence: 94%

Mechanical properties and creep resistance in polystyrene/polyethylene blends

Simonsen

Rochefort

2000

J. Appl. Polym. Sci.

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ABSTRACT:Recycled plastics, predominantly high-density polyethylene (PE), are being processed in the shape of dimension lumber and marketed as "plastic lumber." One drawback to these products is their low creep resistance or high creep speed. The objective of this study was to examine the feasibility of reducing the creep speed of PE-based products by blending the PE with a lower-creep plastic, in this case polystyrene (PS). Various blends of PE and PS were prepared in either a laboratory extruder or a bowl mixer and then compression-molded. The mechanical properties, creep behavior, morphology, and thermal properties of extruded and compressionmolded samples were determined. The modulus of elasticity of the extruded blends could be estimated by a weighted average of PS and PE, even in the absence of a compatibilizer. Processing strongly affected the morphology and mechanical properties of the blends. For 50% PS : 50% PE blends, the stress-strain curves of the extruded samples showed PE-like behavior, whereas those from compressionmolded samples were brittle, PS-like curves. Flexural strength was 50% higher in the extruded samples than in those from compression molding. The creep experiments were performed in three-point bending. Creep speed was lower in 50% PS : 50% PE and 75% PS : 25% PE blends than in pure PS. Creep speed of 75% PS : 25% PE was lowest of all the extruded blends. PE formed the continuous phase even when the PS content was as high as 50 wt %. For a 75% PS : 25% PE blend, cocontinuous phases were observed in the machine direction. A ribbonlike PSdispersed phase was observed in the 25% PS : 75% PE and 50% PS : 50% PE samples. Blending low-creep-speed PS with high-creep-speed PE appeared to successfully improve the performance of the final composite.

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Section: Densitymentioning

confidence: 94%

Mechanical properties and creep resistance in polystyrene/polyethylene blends

Simonsen

Rochefort

2000

J. Appl. Polym. Sci.

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“…The crystallinity of oligomers was also studied by X‐ray diffraction. Lahrouni and Arman32 carried out the crystallinity rate ( X c ) with crystallinity area ( A c ) and amorphous area ( A a ). Like the authors, X c was calculated from the equation: …”

Section: Resultsmentioning

confidence: 99%

Oligomers of poly(anhydride): Study of interaction in coating binder

Lasne-Deschamps

Faÿ

Sire

et al. 2012

J of Applied Polymer Sci

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Polyanhydrides are largely used in biomedical and pharmaceutical fields because of their biodegradability and controlled degradation. In this work, oligomers were investigated as film binders for environmental applications. To overcome the main disadvantages of polyanhydrides (low solubility in common solvents and high melting points), oligomers based on sebacic acid were prepared. Characterization was carried out by nuclear magnetic resonance and electrospray ionization to obtain chemical structures of the products. The formation of weak interactions, which confer cohesion between chains, allows film properties to be observed. The impact of the solvent polarity on the specific organization was investigated by a combination of focused methods: capillary viscosimetry, IR spectroscopy, polarized light microscopy, and X-ray diffraction.

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“…Operators typically focus on problems such as production instability (i.e., helical, draw resonance, oscillating frost line, bubble sagging, tearing, fluttering, and breathing) 12 and others caused by poor dispersion, lack of cohesion, and inadequate viscosity paring when dealing with polymer blends. Laboratory quality assessment such as tensile tests (ASTM D882), Elmendorf tear strength (ASTM D1922), density (i.e., an indication of local polymer compositions 13 ), and crystalline morphology (lamellar, spherulitic, etc.) using microscopy 14 are performed at a low frequency on small samples cut off from the rolls.…”

Section: Introductionmentioning

confidence: 99%

“…14,23 X-ray scattering through a thin sample reveals information about the structure, composition, and properties. In polymer film analysis, X-ray pole figures yield details of crystalline phase orientation 13,14 while a variation of this method, the wide-angle X-ray diffraction (WAXD), refers specifically to sub-nanometer sized crystalline structures. 23 These probes either provide a rapid estimation of the properties of a single localized point on the sample or the average properties of a larger area.…”

Section: Introductionmentioning

confidence: 99%

“…Birefringence, or the decomposition of a light ray as it passes through anisotropic materials, may be used in the determination of the average total (both crystalline and amorphous) orientation of the film. ,, Fourier transform infrared spectroscopy (FTIR) was used for determining the specific orientation factors of the crystalline and amorphous phases. , X-ray scattering through a thin sample reveals information about the structure, composition, and properties. In polymer film analysis, X-ray pole figures yield details of crystalline phase orientation , while a variation of this method, the wide-angle X-ray diffraction (WAXD), refers specifically to sub-nanometer sized crystalline structures . These probes either provide a rapid estimation of the properties of a single localized point on the sample or the average properties of a larger area.…”

Section: Introductionmentioning

confidence: 99%

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Potential of Hyperspectral Imaging for Quality Control of Polymer Blend Films

Gosselin

Rodrigue

González‐Núñez

et al. 2009

Ind. Eng. Chem. Res.

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A visible−near-infrared (VIS-NIR) hyperspectral imaging sensor is proposed for online nondestructive monitoring of polymer film blends produced by extrusion blowing. Such a sensor provides a much higher spatial resolution of analysis compared to probes or probe arrays, which should help in detecting smaller localized defects inducing poor film quality (mechanical, optical, barrier properties) at a macroscopic scale. Multiresolutional multivariate image analysis (MR-MIA) was used to extract those spectral and textural features from images that are the most highly correlated to film composition distribution and mechanical properties. When applied to a low-density polyethylene/polystyrene (LDPE/PS) blend produced under various operating conditions, the imaging sensor was able to monitor the two dominant effects on mechanical properties: (1) the effect of film composition (raw materials) and (2) the stretching effect caused by postextrusion conditions (process).

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Etude de mélanges de polyéthyléne et de polystyrène par diffraction de rayons X et par densimétrie

Cited by 3 publications

References 11 publications

Mechanical properties and creep resistance in polystyrene/polyethylene blends

Mechanical properties and creep resistance in polystyrene/polyethylene blends

Oligomers of poly(anhydride): Study of interaction in coating binder

Potential of Hyperspectral Imaging for Quality Control of Polymer Blend Films

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