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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 Source


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. Source


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. Source


Kartheuser B.,Certech ASBL | Costarramone N.,University of Pau and Pays de lAdour | Pigot T.,University of Pau and Pays de lAdour | Lacombe S.,University of Pau and Pays de lAdour
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. Source


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. Source

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