Werner D.,Northumbria University |
Garratt J.A.,Northumbria University |
Pigott G.,Nufarm UK Ltd
Journal of Soils and Sediments | Year: 2013
Purpose: We review 2,4-dichlorophenoxyacetic acid (2,4-D) and other phenoxy herbicide sorption experiments. Methods: A database with 469 soil-water distribution coefficients Kd (in liters per kilogram) was compiled: 271 coefficients are for the phenoxy herbicide 2,4-D, 9 for 4-(2,4-dichlorophenoxy)butyric acid, 18 for 2-(2,4-dichlorophenoxy)propanoic acid, 109 for 2-methyl-4-chlorophenoxyacetic acid, 5 for 4-(4-chloro-2-methylphenoxy)butanoic acid, and 57 for 2-(4-chloro-2-methylphenoxy)propanoic acid. The following parameters characterizing the soils, solutions, or experimental procedures used in the studies were also compiled if available: solution CaCl2 concentration, pH, pre-equilibration time, temperature, soil organic carbon content (foc), percent sand, silt and clay, oxalate extractable aluminum, oxalate extractable iron (Oxalate Fe), dithionite-citrate-bicarbonate extractable aluminum, dithionite-citrate-bicarbonate extractable iron (DCB Fe), point of zero negative charge, anion exchange capacity, cation exchange capacity, soil type, soil horizon or depth of sampling, and geographic location. Kd data were also compiled characterizing phenoxy herbicide sorption to the following well-defined sorbent materials: quartz, calcite, α-alumina, kaolinite, ferrihydrite, goethite, lepidocrocite, soil humic acid, Fluka humic acid, and Pahokee peat. Results: The data review suggests that sorption of 2,4-D can be rationalized based on the soil parameters pH, foc, Oxalate Fe, and DCB Fe in combination with sorption coefficients measured independently for humic acids and ferrihydrite, and goethite. Conclusions: Soil organic matter and iron oxides appear to be the most relevant sorbents for phenoxy herbicides. Unfortunately, few authors report Oxalate Fe and DCB Fe data. © 2012 Springer-Verlag.
Thatcher R.J.,University of York |
Thatcher R.J.,University of Bristol |
Newby T.E.,University of York |
Price P.,Nufarm UK Ltd |
And 2 more authors.
RSC Advances | Year: 2014
The polymerisation inhibitor, 2-nitrophenol reacts with radicals generated in self-initiated thermal styrene polymerisation to form the unexpected benzoxazine 1. We propose the mechanism for the formation of 1 and show that it is produced by a radical mediated C-H activation. © 2014 the Partner Organisations.
Ma Y.,University of York |
Loyns C.,Nufarm UK Ltd |
Price P.,Nufarm UK Ltd |
Chechik V.,University of York
Organic and Biomolecular Chemistry | Year: 2011
Disproportionation of TEMPO in acids leads to the formation of an N-oxoammonium salt, which can further decompose under thermal conditions, yielding the corresponding hydroxylamine, N 2O, CO 2 and a series of dimerisation products. Overall, acid-catalysed thermal decay of TEMPO leads to ca. 80% yield of hydroxylamine. © 2011 The Royal Society of Chemistry.
NuFarm UK Ltd | Date: 2012-08-20
The invention concerns a formulation and method which allow for the efficient delivery of antipolymerants of low solubility into processes for the production of ethylenically unsaturated monomers, and associated process streams, and which avoid the potential health and safety problems and economic disadvantages which are associated with the methods of the prior art and facilitate the safe and efficient production of these monomers. Specifically, the invention provides an antipolymerant composition for the prevention of unwanted polymerisation reactions during the production and processing of ethylenically unsaturated compounds, the composition comprising a concentrated liquid formulation, wherein said concentrated liquid formulation is a suspension concentrate which comprises: (a) at least one compound selected from the group comprising phenols, quinones, thiazines, hydroxylamines and aromatic amines; (b) at least one dispersing agent; and (c) at least one polar or non-polar liquid carrier. Optionally the composition additionally comprises at least one stable free radical compound, typically a nitroxyl compound, and/or at least one thickening agent and/or at least one preservative agent.
NUFARM UK Ltd | Date: 2011-07-08
The invention relates to a retarder composition for the control of unwanted polymerisation reactions during the production and processing of ethylenically unsaturated compounds, the composition comprising at least one di-substituted quinone compound and at least one hydroxylamine compound. Optionally, the composition also comprises at least one stable free radical nitroxyl compound and one or more formulation adjuvants. The invention also envisages a process stream comprising at least one ethylenically unsaturated compound, and a method for the prevention of unwanted polymerisation reactions during the production and processing of ethylenically unsaturated compounds. The composition has been found to be far more effective than expected, given that the individual components show little or no efficacy when used alone, and poses much less hazard to humans than the compositions of the prior art.