scholarly journals Migration of Bisphenol A from Can Coatings into Beverages at the End of Shelf Life Compared to Regulated Test Conditions

Beverages ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 3 ◽  
Author(s):  
Carina Stärker ◽  
Frank Welle
Keyword(s):  
Bisphenol A ◽  
Shelf Life ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Energy Drinks ◽  
Food Simulants ◽  
Test Conditions ◽  
Food Simulant ◽  
Migration Modeling ◽  
Ethanol In Water

Beverage cans are used for energy drinks, soft-drinks, sparkling waters, and beer. Bisphenol A is still part of the formulation of epoxy coatings of beverage cans. Due to concerns that bisphenol A acts as an endocrine-active substance, the migration of bisphenol A is restricted. Typically, the migration from beverage cans is tested at elevated temperatures into food simulants, like 20% ethanol in water. However, comparison tests of the migration of bisphenol A at the end of shelf life, with the migration into ethanolic food simulants, are not available in the scientific literature. The aim of the study was to determine the migration of the migration of bisphenol A into real beverages, compared to routine migration tests into the European official food simulant of 20% ethanol at 40 °C and 60 °C after storage for 10 days. As a result, bisphenol A-containing coatings show a considerably higher migration when tested at 60 °C in comparison to 40 °C. On the other hand, migration into energy drinks and coke, from the same coatings at the end of shelf life when stored at room temperature, was below the detection limit in either case. As expected, migration values of bisphenol A below the analytical detection limits were observed for any test conditions from the coating labeled bisphenol A-free. Spiking tests show that bisphenol A is stable in real beverages. Therefore, it can be concluded that the accelerated migration tests with 20% ethanol at the test conditions 10 d at 40 °C and 10 d at 60 °C significantly overestimate the real migration into beverages at the end of shelf life. This overestimation of the migration of bisphenol A is due to swelling of the epoxy can coating by the ethanolic food simulant. These findings were supported by migration modeling based on diffusion coefficients predicted for polyethylene terephthalate.

scholarly journals Investigation of bisphenol a diglycidyl ether, bisphenol f diglycidyl ether and their hydroxy and chlorohydroxy derivatives stability in water-based food simulants

2004 ◽  
Vol 22 (SI - Chem. Reactions in Foods V) ◽  
pp. S272-S275
Author(s):  
I. Poustková ◽  
J. Dobiáš ◽  
J. Poustka ◽  
M. Voldřich
Keyword(s):  
Acetic Acid ◽  
Bisphenol A ◽  
Epoxy Resins ◽  
High Performance ◽  
Diglycidyl Ether ◽  
Phase Gradient ◽  
Bisphenol F ◽  
Food Simulants ◽  
Bisphenol A Diglycidyl Ether ◽  
Food Simulant

Varnishes used as the inner coatings of food cans are often based on epoxy resins or vinylic organosols. The epoxy resins can be produced from bisphenol A (BPA) and bisphenol F (BPF) and they also contain bisphenol A diglycidyl ether (BADGE) of bisphenol F diglycidyl ether (BFDGE) as stabilising components. These compounds may break down during storage and also by influence of food simulants. The stability of BADGE and BFDGE was studied using reverse-phase gradient high performance liquid chromatography (RP-HPLC) with fluorescence detection (FLD). Four experiments were compared: (i) BPA solution at the concentration 3 μg/ml of each food simulant, (ii) BADGE solution at the concentration 3 μg/ml of each food simulant, (iii) BFDGE solution at the concentration 3 μg/ml of each food simulant and (iv) mixture of all bisphenols solution at the concentration 3 μg/ml of each food simulant. Distilled water, 10% ethanol, 95% ethanol and 3% acetic acid were used as food simulants. It was observed that BPA, BADGE and BFDGE were most stabile in 95% ethanol and least stabile in 3% acetic acid. Creation of hydroxy and chlorohydroxy derivatives was in each food simulant different so it cannot be predicted.

scholarly journals Functional nano fillers in epoxy-dicyandiamide adhesives for prolonged shelf life and efficient cure

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Jan Christoph Gaukler ◽  
Ulrich Müller ◽  
Jan Kristian Krüger ◽  
Wulff Possart
Keyword(s):  
Elevated Temperature ◽  
Bisphenol A ◽  
Light Microscopy ◽  
Shelf Life ◽  
Ftir Spectroscopy ◽  
Room Temperature ◽  
Network Formation ◽  
Curing Temperature ◽  
Modulated Dsc

AbstractShelf life at room temperature and curing behaviour at elevated temperature are studied for hot-curing accelerated epoxies (EP, diglycidylether of bisphenol A plus dicyandiamide (Dicy)) by FTIR-spectroscopy and modulated DSC. The accelerator is added either directly or with nano-zeolite filler to the EP. Due to the immobilisation of the accelerator in the pores of the nano-zeolite, the shelf life of this EP is 5 times longer than for the EP containing free accelerator. While the free accelerator acts during the whole heating step to curing temperature, the nano-zeolite does not release the accelerator before ca. 100 °C. As monitored by light microscopy, the released accelerator not only supports the curing but also stimulates the dissolution of the solid Dicy. As the result, network formation at 170 °C finishes within less than 25 minutes for the nano-filled EP.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Spherulite Structures in a Melt Spun Fe-Ni Austenitic Steel

1985 ◽  
Vol 43 ◽  
pp. 52-53
Author(s):  
G. M. Michal ◽  
T. K. Glasgow ◽  
T. J. Moore
Keyword(s):  
Austenitic Steel ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Large Range ◽  
Amorphous Structure ◽  
Nucleation And Growth ◽  
Ni Alloys ◽  
Melt Spun ◽  
Crystal Fibers ◽  
Rapidly Solidified

Large additions of B to Fe-Ni alloys can lead to the formation of an amorphous structure, if the alloy is rapidly cooled from the liquid state to room temperature. Isothermal aging of such structures at elevated temperatures causes crystallization to occur. Commonly such crystallization pro ceeds by the nucleation and growth of spherulites which are spherical crystalline bodies of radiating crystal fibers. Spherulite features were found in the present study in a rapidly solidified alloy that was fully crysstalline as-cast. This alloy was part of a program to develop an austenitic steel for elevated temperature applications by strengthening it with TiB2. The alloy contained a relatively large percentage of B, not to induce an amorphous structure, but only as a consequence of trying to obtain a large volume fracture of TiB2 in the completely processed alloy. The observation of spherulitic features in this alloy is described herein. Utilization of the large range of useful magnifications obtainable in a modern TEM, when a suitably thinned foil is available, was a key element in this analysis.

FANSTEEL 85 METAL

Alloy Digest ◽  
1981 ◽  
Vol 30 (6) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Creep Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Good Combination ◽  
Bend Strength ◽  
Temperature Performance

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.

Antioxidant activity of cookiessupplemented with sugarbeet dietary fiber

2011 ◽  
pp. 151-157 ◽  
Author(s):  
Marijana B. Saka ◽  
Julianna F. Gyura ◽  
Aleksandra Mišan ◽  
Zita I. Šereš ◽  
Biljana S. Pajin ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Shelf Life ◽  
Dietary Fiber ◽  
Wheat Flour ◽  
Room Temperature ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Functional Characteristics

The antioxidant activity of cookies prepared by the addition of sugarbeet dietary fibers was investigated in order to estimate their influence on functional characteristics and shelf-life of cookies. Treated fiber (TF) was obtained from sugarbeet by extraction with sulfurous acid (75 °C at pH = 5.7during 60 min) and treatment with hydrogen peroxide (20 g/LH2O2 at pH = 11 during 24 h). The fiber obtained was dried (80 °C), ground and sieved. TF was investigated in comparison with commercially available Fibrex®. The cookies were prepared by the addition of 0, 7, 9 and 11% of sugarbeet dietary fiber as a substitute for wheat flour in the formulation of cookies. The antioxidant properties of cookies were tested every 7 days using a DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity test during 6 weeks of storage at room temperature (23 ± 1 ºC). The obtained results indicated that substitution of wheat flour with Fibrex® in the formulation of cookies upgraded the antioxidant activity, i.e. the functional characteristics of Fibrex®-enriched cookies and could prolong their shelf-life. In contrast, TF did not increase the antioxidant activity of TF-enriched cookies. The better antioxidant activities of Fibrex®-enriched cookies could be attributed to the presence of ferulic acid.

Strong Coupling: Polariton Bose Condensation

2017 ◽  
Author(s):  
Alexey V. Kavokin ◽  
Jeremy J. Baumberg ◽  
Guillaume Malpuech ◽  
Fabrice P. Laussy
Keyword(s):  
Strong Coupling ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Dissipative System ◽  
Bose Condensation ◽  
Einstein Condensation ◽  
Strong Coupling Regime ◽  
Stimulated Scattering ◽  
Exciton Polaritons ◽  
Bose Einstein

In this Chapter we address the physics of Bose-Einstein condensation and its implications to a driven-dissipative system such as the polariton laser. We discuss the dynamics of exciton-polaritons non-resonantly pumped within a microcavity in the strong coupling regime. It is shown how the stimulated scattering of exciton-polaritons leads to formation of bosonic condensates that may be stable at elevated temperatures, including room temperature.

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

Effects of Elevated Temperatures on the Compressive Strength of HFCC

2011 ◽  
Vol 261-263 ◽  
pp. 416-420 ◽  
Author(s):  
Fu Ping Jia ◽  
Heng Lin Lv ◽  
Yi Bing Sun ◽  
Bu Yu Cao ◽  
Shi Ning Ding
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Relative Strength ◽  
Ordinary Concrete ◽  
Residual Compressive Strength ◽  
Fly Ash Concrete ◽  
The Relationship

This paper presents the results of elevated temperatures on the compressive of high fly ash content concrete (HFCC). The specimens were prepared with three different replacements of cement by fly ash 30%, 40% and 50% by mass and the residual compressive strength was tested after exposure to elevated temperature 250, 450, 550 and 650°C and room temperature respectively. The results showed that the compressive strength apparently decreased with the elevated temperature increased. The presence of fly ash was effective for improvement of the relative strength, which was the ratio of residual compressive strength after exposure to elevated temperature and ordinary concrete. The relative compressive strength of fly ash concrete was higher than those of ordinary concrete. Based on the experiments results, the alternating simulation formula to determine the relationship among relative strength, elevated temperature and fly ash replacement is developed by using regression of results, which provides the theoretical basis for the evaluation and repair of HFCC after elevated temperature.

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