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Boborodea A.,Certech ASBL | O'Donohue S.,Agilent Technologies
International Journal of Polymer Analysis and Characterization | Year: 2016

This study presents the possibility of reducing the volume of solvent necessary for gel permeation chromatography analysis by up to 20 times when using two 2.1-mm internal diameter (ID) columns instead of the traditional three 7.5-mm ID columns. The low solvent consumption method was optimized by evaluating the number of theoretical plates at different flow rates. By injecting a broad polystyrene standard 16 times, good reproducibility and accuracy of weight average molecular weights (Mw) and peak surface areas were obtained for the optimized method. 2016 Copyright © Taylor & Francis Group, LLC


Boborodea A.,Certech ASBL | Cleaver G.,Agilent Technologies
International Journal of Polymer Analysis and Characterization | Year: 2016

The increasing polyphenylene sulfide (PPS) world demand due to its unique mechanical and chemical properties has augmented the pressure on development of analytical methods to evaluate its molecular weight distribution and structure. This article presents gel permeation chromatography with triple detection (GPC3D) performed in chloronaphthalene at 210°C on a commercially available instrument as a possible method to elucidate the structure properties of linear and branched PPS. The procedure allows measurement in a single run of the true molecular weight distributions and intrinsic viscosities, the Mark-Houwink parameters, and the number of long chain branches. © 2016, Copyright © Taylor & Francis Group, LLC.


Boborodea A.,Certech ASBL | Brookes A.,Agilent Technologies
International Journal of Polymer Analysis and Characterization | Year: 2015

The increasing world demand for polyphenylene sulfide (PPS) due to its unique properties has augmented the pressure on development of analytical methods to evaluate its molecular weight distribution and structure. Whilst gel permeation with triple detection (GPC3D) has been considered for PPS analysis, its development and effectiveness has been impaired because of, firstly, the high temperature needed to maintain solubility (>205°C), and, secondly, a very low dn/dc for the polystyrene calibration standards in 1-chloronaphthalene. This article presents practical recommendations to overcome these early difficulties by discussing the results obtained on PPS samples analyzed with a commercially available GPC3D instrument. © 2015, Copyright © Taylor & Francis Group, LLC.


Boborodea A.,Certech ASBL | Collignon F.,Certech ASBL | Brookes A.,Agilent Technologies
International Journal of Polymer Analysis and Characterization | Year: 2015

This study presents the possibility of replacing the 1,2,4-trichlorobenzene (TCB) recommended by ASTM D 6474 for the analysis by gel permeation chromatography (GPC) of linear polyethylenes with dibutoxymethane (DBM, butylal), a halogen-free and less toxic solvent. The molecular weight distributions as well as the K and alpha parameters of the Mark-Houwink-Sakurada relationship were measured for polyethylene solutions in TCB and DBM, using a GPC system with triple detection (light scattering, differential refractive index, and viscometer). For commercial metallocene polyethylene resins typically used for film and packaging applications, the GPC method in DBM provided results comparable to those obtained in TCB. © 2015 Taylor & Francis Group, LLC.


Kartheuser B.,CERTECH asbl | Costarramone N.,University of Pau and Pays de l'Adour | Pigot T.,University of Pau and Pays de l'Adour | Lacombe S.,University of Pau and Pays de l'Adour
Environmental Science and Pollution Research | Year: 2012

Background, aim: The aims of the NORMACAT project are: to develop tools and unbiased standardized methods to measure the performance and to validate the safety of new materials and systems integrating photocatalysis, to develop new photocatalytic media with higher efficiency and to give recommendations aimed at improving the tested materials and systems. Method: To achieve this objective, it was necessary to design standardized test benches and protocols to assess photocatalytic efficiency of materials or systems used in the treatment of volatile organic compounds (VOCs) and odour under conditions close to applications. The tests are based on the validation of robust analytical methods at the parts per billion by volume level that not only follow the disappearance of the initial VOCs but also identify the secondary species and calculate the mineralization rates. Results: The first results of inter-laboratory closed chamber tests, according to XP B44-013 AFNOR standard, are described. The photocatalytic degradation of mixtures of several defined pollutants under controlled conditions (temperature, relative humidity, initial concentration) was carried out in two independent laboratories with the same photocatalytic device and with various analytical procedures. Comparison of the degradation rate and of the mineralization efficiency allowed the determination of the clean air delivery rate in both cases. Formaldehyde was the only by-product detected during photocatalytic test under standardized experimental conditions. The concentration of transient formaldehyde varied according to the initial VOC concentration. Moreover the photocatalytic reaction rate of formaldehyde in mixture with other pollutants was analysed. It was concluded that formaldehyde concentration did not increase with time. Conclusion-perspective: This type of experiment should allow the comparison of the performances of different photoreactors and of photocatalytic media under controlled and reproducible conditions against mixtures of pollutants including formaldehyde. © 2012 Springer-Verlag.


Boborodea A.,Certech ASBL | Mirabella F.M.,Mirabella Practical Consulting Solutions Inc.
International Journal of Polymer Analysis and Characterization | Year: 2014

Temperature rising elution fractionation (TREF) became the preferred technique to characterize the short chain branching distribution of polyethylene copolymers. Due to technical limitations, preparative TREF (PTREF) is usually done in xylene, while trichlorobenzene is used in analytical TREF (ATREF). Attempts to correlate the TREF elution temperatures based on data published by different authors erroneously showed higher elution temperatures for xylene than for trichlorobenzene. Our study rectifies this error. The experiments were done in both solvents on the same analytical TREF instrument. For the analyzed polyethylene copolymers, we found that the average elution temperature in xylene is 3.7° ± 1°C lower than in trichlorobenzene. © 2014 Copyright Taylor & Francis Group, LLC.


Boborodea A.,Certech ASBL | Luciani A.,Certech ASBL
International Journal of Polymer Analysis and Characterization | Year: 2014

Fast analytical temperature rising elution fractionation (ATREF) is a recently proposed method to evaluate the molecular structure of polyolefins with unimodal distributions. In this article, we compare the results obtained by this method and the classical slow cooling rate ATREF. An interpretation of previous results found in the literature is proposed in order to explain one of the limitations usually associated with this technique. Practical recommendations are given to build columns adapted to this technique and to efficiently adjust the method parameters. © 2014 Taylor & Francis Group, LLC.


Boborodea A.,Certech ASBL | Michel J.,Total Research and Technology | Luciani A.,Certech ASBL
International Journal of Polymer Analysis and Characterization | Year: 2014

Conventional analytical temperature rising elution fractionation (ATREF) is performed using slowly crystallized polymers in about 16 h. In this work, we developed a fast ATREF method in which the polymer sample is directly injected on the column at room temperature, thus reducing the analysis time to about 1 h. The method was tested using four metallocene polyethylenes with unimodal short chain branching distributions and different densities, previously analyzed by ATREF using a cooling rate of 0.1°C/min. The obtained results demonstrate that the fast ATREF method is very effective and accurate in evaluating short chain branching distribution for polyolefins having unimodal distributions. © 2014 Copyright Taylor & Francis Group, LLC.


Boborodea A.,Certech ASBL | Luciani A.,Certech ASBL
LCGC North America | Year: 2013

This article presents a new method to evaluate the temperature shift observed in analytical temperature rising elution fractionation (ATREF). The evaluation is based on the dependence of the measured peak temperature as a function of heating rates. Application of the proposed method does not require any knowledge of the fluid circuit characteristics geometry and avoids the use of narrow preparative TREF standards. The results are found to be more accurate than the method that is usually applied.


Patent
Certech A.S.B.L. | Date: 2012-02-29

An extinguisher has a cylinder capable of containing a fire-extinguishing product, and means for releasing the fire-extinguishing product from the cylinder and comprising at least one compressed gas cartridge, at least two tanks, each capable of containing at least one additive product, and means for releasing at least one additive product from each of the at least two tanks and for mixing with the fire-extinguishing product during the release of the fire-extinguishing product. At least one of the tanks is removable relative to the extinguisher. A cartridge having a plurality of tanks is usable in the extinguisher.

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