Synthesis and properties of oligodiuretane diisocyanates and oligotetraurethanes based on a mixture (2.4÷2.6) of toluene diisocyanate

Abstract

By the reaction of a mixture of isomers (2.4-2.6) of toluene diisocyanate with aliphatic, individual or oligomeric diols (such as polyoxypropylene glycols of different molecular weight) in cyclohexanone, oligodiurethane diisocyanates with the diol component of different nature and length in their structure are synthesized in the first stage. In the second stage, the synthesized oligodiurethane diisocyanates were blocked by monofunctional aliphatic alcohols of normal structure with different lengths of fatty radical. The structure of the latter is confirmed by the absence of absorption bands characteristic of free –NCO groups in the IR spectra. Both series of isolated oligodiureta diisocyanates and oligotetraurethanes are characterized by refractive index and Ubellode drop temperature, molecular weights, content of free –NCO groups, and IR spectra. They are well soluble in esters, ethers, chlorinated and aromatic hydrocarbons, ketones, and aprotic solvents; they are poorly soluble in aliphatic hydrocarbons. The presence in the structure of such compounds of polar urethane groups simultaneously with relatively high molecular weight suggests that they will be useful not only as plasticizers, but also as modifiers of the properties of polymers and composite materials.