Diureas

Post-curing and chemical modification improves chemical and solvent resistance (20). Paraformaldehyde and acetylene diurea are added to a hot borax solution. Toluenesulfonamide (p and o), a few drops of phosphorous acid. Brilliant Yellow 6G [2429-76-7] Rhodamine E3B, and Rhodamine 6GDN [989-38-8] are added. After heating, the mass is cured in an oven at 150°C. The resulting cured resin is thermoset but can be ground to fine particle sizes. 

About 69% of the total 1988 U.S. consumption of isobutyraldehyde, went into the production of isobutyl alcohol and isobutyraldehyde condensation and esterification products. The other principal isobutyraldehyde derivative markets (as a percentage of total 1988 U.S. isobutyraldehyde consumption) are neopentyl glycol (15%) isobutyl acetate (6%) isobutyric acid (5%) isobutyUdene diurea (2.5%) and methyl isoamyl ketone (1.7%). 

Isobutyhdene diurea (IBDU), a slow release fertilizer, is formed from isobutyraldehyde and two moles of urea. 

Fig. 1. United States agricultural crop markets for manufactured controlled release fertilizers, 1990. (a) Total percentage ( 14 million) of market value by crop and (b) total percentage (6,800 t) of consumption by product type. IBDU is isobutyUdene diurea PCF, polymer-coated fertilizer UF,...

Gra.nula.r Compositions. Granular compositions of UF reaction products are divided into three classes, each based on their degree of water solubihty as affected by their polymer distributions, ie, ureaform, the least water-soluble class methylene ureas and methylene diurea/dimethylene triurea (MDU/DMTU) compositions, the shortest-chain MU oligomers and the most water-soluble. 

Urea—Other Aldehyde Reaction Products. Urea can also react with other aldehydes to form slow release nitrogen fertilizers. However, cost constraints associated with higher aldehydes have either precluded or limited broad commercial development of these products. Two exceptions are isobutyhdene diurea (IBDU), registered trademark of Vigoro Industries, and crotonyHdene diurea (CDU), registered trademark of Chisso-Asahi Fertilizer Co. 

Isohutyhdene Diurea., This is the condensation product of urea and isobutyraldehyde. Unlike the condensation of urea with formaldehyde, which forms a distribution of different UF polymer chain lengths, the reaction of urea with isobutyraldehyde forms a single oligomer. Although similar in chemical stmcture to methylene diurea (MDU), its physical properties are quite different (Table 4). 

Isobutylene diurea Croton dene diurea Ox amide Melamine... 

Isobutyhdene diurea [6104-30-9] is a nonhygroscopic white crystalline soHd available in fine (0.5—1.0 mm), coarse (0.7—2.5 mm), and chunk (2.0—3.0 mm) particle sizes. The AAPFCO official definition requires a minimum nitrogen content of 30% with 90% of the nitrogen in water-insoluble form prior to grinding (3). 

Crotonylidene Diurea. (CDU). Crotonjlidene [1129 2-6] is produced by the acid catalyzed reaction of urea with either crotonaldehyde or acetaldehyde. The condensation reaction produces a ring-stmctured compound. Table 4 hsts select properties. 

Dihamstoff, m. diurea (urazine). diheteroatomig, a. diheteratomic. dlhezaedrisch, a. Crysi.) dihexahedral. dihydratisch, a. dihydric. 

Isobutyl heptyl ketone (IBHK), 14 585 Isobutylidene diurea (IBDU)... 

G. M., and Rao, K.P.C. (1999) Synthesis and characterization of tetranitropropane diurea (TNPDU) a high density explosive. HEMRL Technical Report No. HEMRL/RES/99/4. 

DiharnStoff (Ger for Diurea). See Note under 4-Aminourazole in Vol 1, p A272-L and Diurea in this Vol... 

Diurea. See in Vol 1, A472-L under 4-Amino-Urazole and in Vol 5, D1523-L... 

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