Search results for "phthalate"

Structure development in poly(ethylene terephthalate) quenched from the melt at high cooling rates: X-ray scattering and microhardness study

2000

The structure and microhardness of poly(ethylene terephthalate) (PET) cooled from the melt, using a wide range of cooling rates, was studied. PET thin films rapidly cooled from the melt (cooling rates larger than 5°C/s) show a continuous variation of structure and properties depending on cooling rate. Results highlight differences in the micro-mechanical properties of the glass suggesting the occurrence of amorphous structures with different degrees of internal chain ordering. The comparative X-ray scattering study of two glassy PET samples (7500 and 17°C/s) reveals the occurrence of frozen-in electron density states giving rise to an excess of scattering for the amorphous sample solidified…

From single fiber to macro-level mechanics: A structural finite-element model for elastomeric fibrous biomaterials

2014

In the present work, we demonstrate that the mesoscopic in-plane mechanical behavior of membrane elastomeric scaffolds can be simulated by replication of actual quantified fibrous geometries. Elastomeric electrospun polyurethane (ES-PEUU) scaffolds, with and without particulate inclusions, were utilized. Simulations were developed from experimentally-derived fiber network geometries, based on a range of scaffold isotropic and anisotropic behaviors. These were chosen to evaluate the effects on macro-mechanics based on measurable geometric parameters such as fiber intersections, connectivity, orientation, and diameter. Simulations were conducted with only the fiber material model parameters a…

Phthalate esters in coffee brew samples: Analytical method by GC-MS, profile, levels and sources

2012

The present study was aimed to develop a procedure for the analysis of trace concentration of phthalate esters (PEA) in coffee brew stored in plastic cups. Phthalates are esters of phthalic acid, generally have high boiling points, lowvolatility are insoluble in water andpredominantly fat-soluble. Phthalates with higher molecular weights, such as bis(2-ethylhexyl) phthalate (DEHP) are largely used as additives and plasticizers in plastic material (PVC), while those with lower molecular weights are components of solvents, adhesive, wax, ink, pharmaceutical products, insecticide materials and cosmetic. Dimethyl phthalate and diethyl phthalate are present in plastics based on cellulose esters …

Reprocessing of polyethyleneterephthalate and characterisation of monopolymer blends of virgin and recycled polymers

1997

Recycling of polyethyleneterephthalate (PET from bottles is considered by changing both reprocessing machines and the effect of humidity. The rheological and mechanical properties of this recycled material remain very close to that of the virgin material provided that a careful drying is carried out before any melt operation. The reprocessing has been carried out mainly in view of the use of this secondary material in blends with virgin PET-monopolymer or homopolymer blends. Indeed, this use is a common industrial practice to reuse plastic scraps. Most monopolymer blends show properties between those of the two components but in some cases lower than those expected on the basis of an additi…

A statistical design of experiments for optimizing the MALDI-TOF-MS sample preparation of polymers. An application in the assessment of the thermo-me…

2011

[EN] The sample preparation procedure for MALDI-TOF MS of polymers is addressed in this study by the application of a statistical Design of Experiments (DoE). Industrial poly (ethylene terephthalate) (PET) was chosen as model polymer. Different experimental settings (levels) for matrixes, analyte/matrix proportions and concentrations of cationization agent were considered. The quality parameters used for the analysis were signal-to-noise ratio and resolution. A closer inspection of the statistical results provided the study not only with the best combination of factors for the MALDI sample preparation, but also with a better understanding of the influence of the different factors, individua…

1985

Investigations with ca. 100 organic liquids in a temperature range from −20°C to 90°C result in a survey of the solubility behaviour of PVC. The experimental results were compared with the predictions of the solubility parameter theory: Accepting δ = 9,75 (cal/cm3)1/2 as the solubility parameter for PVC, all solvents (except ketones in which PVC is soluble independent of their solubility parameters) are located within the range of δPVC ± 0,75. Only three of the 100 liquids examined turned out to be (endothermal) theta-solvents, namely the aromatic solvents o-xylene, phenetole and dimethyl phthalate. The theta-temperatures in o-xylene and phenetole were determined viscometrically by means of…

CCDC 1402188: Experimental Crystal Structure Determination

2015

Related Article: Georges Mouchaham, Marion Gualino, Nans Roques, Carine Duhayon, Stéphane Brandès, Jean-Pascal Sutter|2015|CrystEngComm|17|8906|doi:10.1039/C5CE01070E

CCDC 1491309: Experimental Crystal Structure Determination

2016

Related Article: Verónica Jornet-Mollá, Yan Duan, Carlos Giménez-Saiz, João C. Waerenborgh, Francisco M. Romero|2016|Dalton Trans.|45|17918|doi:10.1039/C6DT02934E

CCDC 633306: Experimental Crystal Structure Determination

2007

Related Article: O.Fabelo, J.Pasan, F.Lloret, M.Julve, C.Ruiz-Perez|2007|CrystEngComm|9|815|doi:10.1039/b706035c

Evaluation of anti-androgenic activity of di-(2-ethylhexyl)phthalate

2005

International audience; DEHP is a widely used platiciser in the manufacture of PVC-based materials. It is known to disrupt the reproductive tract development in male rats. We have performed the Hershberger assay with DEHP on an immature castrated rat model to check if DEHP antagonise the testosterone propionate androgenic effect on the accessory sex organs development. DEHP significantly decreased the BC/LA muscles, the prostate, and the seminal vesicles relative weights from 100, 200, and 400 mg/kg bw/day, respectively. DEHP increased the liver relative weight from 100 mg/kg bw/day. A study was also performed on MDA-MB453 cell line stably transfected with pMMTVneo-Luc with DEHP and its maj…