2,4-Toluene diisocyanate polyurethane synthesis

We will return to these reactions later in connection with polyurethanes because one monomer in polyurethanes is toluene diisocyanate, and the first step in its synthesis is the production of dinitrotoluene. 

Phosgene is a key intermediate used in synthesis of many chemicals, a major one being toluene diisocyanate, a monomer in polyurethanes. Phosgene is made from chlorine and carbon monoxide through the overall reaction... 

Hafnium triflate has also been used for acylation and alkylation of aromatic compounds.64 It has also been used in aromatic nitration in a process (6.18) that eliminates the usual waste acid from such reactions.65 The products are intermediates in the synthesis of toluene diisocyanates used in making polyurethanes. The catalyst could be reused with... 

Ding YS, Register RA, Yang C, Cooper SL. Synthesis and characterization of sulphonated polyurethane ionomers based on toluene diisocyanate. Polymer 1989 30(7) 1204-12. 

If a small amount of glycerol is added to the reaction mixture of toluene-2,6-diisocyanate and ethylene glycol during the synthesis of polyurethane foam, a much stiffer foam is obtained. Explain. 

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