Herbicide-polyurethane derivatives

Monomeric herbicides of diethanolamine derivatives were also prepared, followed by melt polycondensations with dicarboxylic acids to give the corresponding herbicide polyesters (Scheme 3.14) [139]. Solution polycondensation was used in the synthesis of the herbicide-polyurethane derivatives by the reaction of diethanolamine derivatives with HMDI. The linear polymers were crosslinked by reaction with HMDI (5, 10 %) to afford swellable polymeric materials. The preformed amine-containing polyester was also modified with 2,4-D. The hydrolysis rate of 2,4-D from the polymers was measured under different simulated conditions. 

Carbamic acid esters (methanes) and their derivatives are important precursors to agrochemicals (herbicides, fungicides, and pesticides) as well as to pharmaceuticals. Also, they can be transformed to isocyanates, which are major building blocks for polyurethanes, widely used in construction, transportation, and several other fields. Presently, the main technical process for the manufacture of isocyanates is phosgena-tion of the corresponding amines. Since the global consumption of polyurethane raw... 

The biochemical reaction catalyzed by epoxygenase in plants combines the common oilseed fatty acids, linoleic or linolenic acids, with O2, forming only H2O and epoxy fatty acids as products (CO2 and H2O are utilized to make linoleic or linolenic acids). A considerable market currently exists for epoxy fatty acids, particularly for resins, epoxy coatings, and plasticizers. The U.S. plasticizer market is estimated to be about 2 billion pounds per year (Hammond 1992). Presently, most of this is derived from petroleum. In addition, there is industrial interest in use of epoxy fatty acids in durable paints, resins, adhesives, insecticides and insect repellants, crop oil concentrates, and the formulation of carriers for slow-release pesticides and herbicides (Perdue 1989, Ayorinde et al. 1993). Also, epoxy fatty acids can readily and economically be converted to hydroxy and dihydroxy fatty acids and their derivatives, which are useful starting materials for the production of plastics as well as for detergents, lubricants, and lubricant additives. Such renewable derived lubricant and lubricant additives should facilitate use of plant/biomass-derived fuels. Examples of plastics that can be produced from hydroxy fatty acids are polyurethanes and polyesters (Weber et al. 1994). As commercial oilseeds are developed that accumulate epoxy fatty acids in the seed oil, it is likely that other valuable products would be developed to use this as an industrial chemical feedstock in the future. 

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