1,4-phenylene diisocyanate

A segmented polyurethane eonsisting of poly(oxybutane-l,4-diyl) bloeks joined through junetion units derived from 1,3- and 1,4-phenylene diisocyanate and arranged alternately ... 

The most widely used method for the dehydration of primary nitroalkanes involves their treatment with phenyl isocyanate and triethylamine, introduced in 1960 by Hoshino and Mukaiyama (7). A probable mechanism for the formation of the nitrile oxide is shown in Scheme 6.4. This method is known to be very effective for the preparation of aliphatic or aromatic nitrile oxides. In some cases, the separation of the byproduct A,A -diphenylurea from the reaction mixture may be troublesome. In order to circumvent this problem, 1,4-phenylene diisocyanate was introduced (82,83). The polymeric urea that is formed as a byproduct is largely insoluble in the reaction mixture and can easily be removed. 

To purify solution-phase libraries of amides and sulfonamides, a scavenger approach based upon the removal of excess reactants by polymerization and simple filtration has been employed [45]. Co-polymerization of 1,4-phenylene diisocyanate and pentaethylenehexamine was used to remove the excess amine as an insoluble, filterable urea. An excess of acyl or sulfonyl chloride can also be scavenged by polyamine and diisocyanate, depending on the order of addition (Scheme 16). The desired amides 46 and sulfonamides were obtained in good yield (> 64%) and with high purity (87% on average). 

Preparation of 46 [45] Procedure for the formation of amides 46 or sulfonamides using an acid chloride or sulfonyl chloride, respectively, and excess amine To a solution of the acid chloride or sulfonyl chloride (0.1 mmol) in dichloromethane (1 niL) was added a solution of the amine (3 equiv.) in dichloromethane (1 mL). The mixture was stirred at rt for 30 min and then a solution of 1,4-phenylene diisocyanate (6 equiv.) in dichloromethane (4 mL) was added. The resulting mixture was stirred at rt for 40 min and then a solution of pentaethylenehexamine (2.5 equiv.) in dichloromefhane (4 mL) was added. After stirring for 1 h, the heterogeneous mixture was filtered. Concentration of the filtrate under reduced pressure afforded the expected amide 46 or sulfonamide. 

Instead of binding excess reagents to a solid phase they can be precipitated via polymer formation. Thus, excess amines used in acylation or sulfonation reactions can be precipitated as insoluble polymeric ureas by first adding excess 1,4-phenylene-diisocyanate and secondly penta-ethylene hexamine [138]. 

Reactivity Studies and Cast Elastomers Based on fra/is-Cyclohexane-l,4-Diisocyanate and 1,4-Phenylene Diisocyanates... 

Besides aliphatic diisocyanates, an aromatic isocyanate was also used to prepare polyurethanes. A new renewable copolymer (Scheme 17) was synthesized from reactive bis-hydroxylated poly(3-hydroxybutyrate-co-3-hydroxyvalerate) oligomers (PHBHV-diol), isosorbide, and 1,4-phenylene diisocyanate. The molar number-average molecular weights (M of most of the copolyesters were about... 

Suitable starting compounds are polyesters from poly(ethylene oxide) and adipic acid, also poly(propylene oxide) or poly(oxytetramethylene) with molecular weights around 2,000, whose hydroxy end groups can be reacted with very reactive diisocyanates such as 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, and diphenylmethane-4,4 -diisocyanate. 

Dogan et al. (2013) prepared blends of poly(lactic acid) with TPU through addition of 1,4-phenylene diisocyanate coupling agent. Characterization techniques included mechanical, thermal, morphological, and rheological properties. 

Polyurea membranes have been produced in the reaction between L-Lysine ethyl ester dihydrochloride with 1,4-phenylene diisocyanate, followed by dissolving the polymer in DMAc/LiCl (5%) and obtaining the membrane by evaporation of the solvent [56]. By the addition to the membrane synthesis mixture of N-a membrane-benzyloxycarbonyl-D-glutamic acid (ZD-Glu) or N-a-benzyloxycarbonyl-L-glutamic acid (ZL-Glu), and extraction of these imprint molecules using a solution of ethanol in water, a molecularly imprinted membrane is obtained, which has an affinity for Z-D-Glu or Z-L Glu. The material thus obtained was used for enantioselective electrodialysis, the imprinted molecule being retained in the membrane, and transport being allowed only for the other enantiomer. 

Poly( 1,4-phenylene diisocyanate-CY -poly( 1,4-butanediol)) X9339-41 -3 Poly(oxy-1,4-butanediyl ),a-hydro- o-hydroxy-, polymer with 1,4-diisocyanato benzene R (CsH4N202 (C4H80) HjO) ... 

Functionalized linear polyphosphazenes can be included into copolymers as demonstrated through the formation of a polyurethane material with fiuorinated linear phosphazene polymeric content.A precursor material is formed from 2-methyl-1,4-phenylene diisocyanate and poly(tetramethylene glycol). This material is then reacted with a fiuorinated phosphazene (42) in the presence of 2,2-bishydroxymethyl-l-butanol to yield a cross-linked polyurethane-polyphosphazene material. The methacrylate moiety also has been demonstrated to create cross-linked phosphazene-organic hybrid materials. Poly(bis-methacrylate)phosphazene (43) was formed under mild (ambient) conditions to prevent premature cross-linking. 

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