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Phosphorous-Based FRs
Published in Asim Kumar Roy Choudhury, Flame Retardants for Textile Materials, 2020
Inorganic phosphorous derivatives, mostly nondurable or semidurable, entail primarily phosphoric acid and its ammonium salts, e.g., diammonium phosphate (DAP, (NH4)2 HPO4) are highly effective FRs and smoldering inhibitors. While only 15% of either of them is required for flame retardancy, 50–70% of its sodium salt is required to have the same effect.
Role of Nanoclay Polymers in Agriculture: Applications and Perspectives
Published in Surender Kumar Sharma, Nanohybrids in Environmental & Biomedical Applications, 2019
Nanoclay polymer composites are prepared according to the standard procedure by Liang and Liu (2007). The chemicals required for the preparation are as follows: a source of ammonia (urea and diammonium phosphate (DAP) granule fertilizer), acrylic acid, acryl amide, the cross-linker (N, N¢-methylene bisacrylamide) and ammonium persulfate. Briefly, acrylic acid and acryl amide are dissolved in distilled water and then neutralized (neutralization degree = 60%) with the sources of ammonia listed above in a three-necked flask with a condenser, a thermometer and an opening for nitrogen gas to be added in the reaction mixture. In the three-necked flask, clay is added and dispersed by placing the flask on a magnetic stirrer with a heating control. Under a nitrogen atmosphere, N, N¢-methylene bisacrylamide is added to the mixture solution and stirred on the magnetic stirrer at room temperature for 30 minutes. After a radical initiator, vigorous stirring with a gradual increase in temperature (70°C) is started and ammonium persulfate is added to the mixture. The resulting product after polymerization is washed several times with distilled water, dried at 100°C to a constant weight and screened.
Flame Retardance of Fabrics
Published in Menachem Lewin, Stephen B. Sello, Handbook of Fiber Science and Technology: Chemical Processing of Fibers and Fabrics, 2018
Phosphorylation: It is not surprising, therefore, that considerable efforts were made to develop fully durable FR treatments with low add-ons of chemicals that would overcome the above problems. The first endeavors in this direction were made on phosphorylation of cellulose by phosphoric acid and diammonium phosphate [306–310]. The phosphorus content of these materials is high and lower only than in red phosphorus. Phosphorylation can be carried out with many agents: ortho-, meta-, pyro-, poly-hexameta-phosphoric acid, ortho-, pyro-, poly-, meta-phosphorous acid, POCl3, di-ammonium phosphate, and urea-phosphoric acid. The phosphorylation is carried out by a pad-dry-cure procedure, usually with high yields. The cellulose is severely degraded by the drying and curing at the relatively high temperatures and the low pH values involved. The form of the original acid and its valency have no effect on the phosphorylation reaction. Substituents of high carbon content decrease the acid effectiveness. The flame resistance of the cellulose esterified with ethyl-, phenyl-, or boron-substituted phosphoric acid is inferior [307]. Halogen-substituted phosphoric acids cause greater degradation on curing. Urea assists the phosphorylation and it is believed that it serves as a limited swelling agent for the cellulose and a solvent for the phosphorylating agent, since it is in the molten state in the range of curing temperatures used -130–170°C [308]. The addition of urea also decreases the extent of degradation of the cellulose. Below 170°C, an ammonium cellulose ester is formed.
Life cycle assessment of cane sugar production: The environmental contribution to human health, climate change, ecosystem quality and resources in México
Published in Journal of Environmental Science and Health, Part A, 2019
Ramiro Meza-Palacios, Alberto A. Aguilar-Lasserre, Luis F. Morales-Mendoza, Jorge R. Pérez-Gallardo, José O. Rico-Contreras, Alejandro Avarado-Lassman
About nitrogen fertilizers, for example, the diammonium phosphate (DAP) has a concentration equal to 18–46 (18% of ammoniacal nitrogen and 46% of total phosphorus). At the LCI data, an average of 0.885 kg of DAP/ton of sugarcane was reported. This data should be separated by its content of nitrogen and phosphorus to facilitate its inclusion in SimaPro software. In Eq. (1), an example of how to estimate nitrogen and phosphorus percentage is shown: