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Vangronsveld E.,Huntsman Polyurethanes
International Wood Products Journal | Year: 2012

Methylene diphenyl diisocyanate (MDI) is being used increasingly as an alternative resin in the composite wood industry for environmental, indoor air, production capacity or quality reasons. This paper gives an overview of the hazards, classification, regulations and exposure risks related to the use of MDI and MDI bonded wood products. Its aim is to provide factual scientific information to address some of the concerns regularly encountered when introducing MDI as a resin. Like all chemicals, MDI has its hazards and is regulated within existing regulatory frameworks like Globally Harmonized System (GHS) the European Regulation for the REACH, Evaluation, Authorization and Restriction of Chemicals (REACH) and Classification, Labelling & Packaging (CLP). It is important to understand the risks associated with chemicals in the workplace to raise awareness with workers. Understanding safety issues has equal value in identifying where to implement risk reduction measures so workers are protected, and in ensuring investments are economically feasible. The inhalation exposure risks of MDI are given based on an extensive dataset and compared with other agents present in the workplace, i.e. wood dust and formaldehyde. In addition, this paper addresses the risk for consumers for the use of MDI bonded composite wood products (CWPs). The conclusion is that MDI has been classified as a hazardous chemical; however, safe use can be demonstrated within the REACH framework. The exposure risks of MDI, compared to other chemical agents present in the workplace, are significantly lower and can be reduced further if actions are taken to control wood dust. Furthermore, there is no need for concern regarding exposure to consumers if MDI bonded CWPs are used in buildings or homes. © 2012 IWSc.

Hamdy M.S.,Wageningen University | Hamdy M.S.,Helwan University | Scott E.L.,Wageningen University | Carr R.H.,Huntsman Polyurethanes | Sanders J.P.M.,Wageningen University
Catalysis Letters | Year: 2012

The photocatalytic conversion of an aqueous solution of l-tryptophan (Trp) to kynurenine (KN) was investigated under the illumination of different light sources. Results show that Trp converted to KN with a selectivity of 64% under the illumination of a medium pressure (MP) Hg lamp. KN selectivity was increased to >90% when black light (BL) was used a light source. The novel use of BL in the photocatalytic conversion of Trp to KN significantly reduces the energy consumption compared with MP light. © 2012 The Author(s).

Alexander A.-M.,University of Glasgow | Hargreaves J.S.J.,University of Glasgow | Mitchell C.,Huntsman Polyurethanes
Topics in Catalysis | Year: 2012

Metal nitrides may be of interest as potential sources of activated nitrogen which can be reacted with target organic molecules. Accordingly, the reduction of nitrogen within Ni 3N, Cu 3N, Zn 3N 2 and Ta 3N 5 under a 1/3 Ar/H 2 flow at elevated temperature has been determined as a simple test of lattice nitrogen reactivity. As anticipated by consideration of their stability, Ni 3N and Cu 3N are reduced completely at 250 °C with up to 30 % of their total lattice nitrogen yielding ammonia. The elimination of N2 results in the formation of pores which are particularly pronounced in the case of the denitrided Cu system. In the case of Zn 3N 2, the lattice nitrogen is less reactive with incomplete denitridation being observed at 400 °C and the amount of ammonia produced being 15 % of the total nitrogen available. Although Ta 3N 5 contains the least reactive nitrogen of the four samples studied, it can be regenerated by ammonolysis which is an important consideration in any envisaged application. © Springer Science+Business Media, LLC 2012.

Harikrishnan G.,Indian Institute of Technology Kharagpur | Patro T.U.,Indian Institute of Technology Bombay | Patro T.U.,Defense Institute of Advanced Technology | Unni A.R.,Huntsman Polyurethanes | Khakhar D.V.,Indian Institute of Technology Bombay
Soft Matter | Year: 2011

Remarkable evolutionary changes in cell morphology during reactive polymer nanocomposite foaming are observed by controlled foaming of suspensions of montmorillonite clay in the oligomeric polyurethane component. Delaminated nanoplatelets, when present as a networked cluster in suspensions, are shown to have very high efficiency in generating gas embryos for bubble nucleation. In the post-nucleation foaming period, clay nanoplatelets show an additional de-wetting behavior. The packing fraction of clay platelets in suspension and the consequent suspension rheology affect the final foam morphology. © 2011 The Royal Society of Chemistry.

Alexander A.-M.,University of Glasgow | Alexander A.-M.,Ohio State University | Hargreaves J.S.J.,University of Glasgow | Mitchell C.,Huntsman Polyurethanes
Topics in Catalysis | Year: 2013

The denitridation behaviour of binary iron, cobalt and rehnium nitrides under H2 /Ar has been investigated. The iron nitride was found to lose over 70 % of its as prepared nitrogen content at 400 C. The cobalt nitride was completely denitrided at 250 C. Rhenium nitride lost close to 90 % of its nitrogen at 350 C. In addition, Co-Re4 prepared by ammonolyis was investigated, whilst only traces of NH3 were lost from this material under H2/Ar at 400 C, with H2/N2 it proved to be an active ambient pressure ammonia synthesis catalyst in accordance with previous literature. © 2013 The Author(s).

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