Synthesis and physical–mechanical study of nitrated oligodivinyldiol based polyurethanes

Novel frost-resistant polymers based on oligodivinylisoprenediol with a molecular weight ~ 4000 (VID) and its chemically modified analogues (NVID-1, NVID-2, NVID-3) and isophorone diisocyanate have been synthesized for the first time. In order to improve the adhesive and mechanical properties of the NVID-based polymer while maintaining a low glass transition temperature, targeted chemical modification of oligodivinylisoprenediol was carried out for the first time by introducing polar nitro groups into the oligomer chain. As a result, three modified oligodiols (NVID-1, NVID-2, NVID-3) were obtained with a nitro group content in the range from 0.54% to 2.62%. It was found that the dynamic viscosity of the compositions increases with the content of nitro groups in the oligomer. The properties of the polymers were characterized using DSC, TGA, mechanical tensile and adhesion tests. The test results indicate that in the studied range of nitro group content, the glass transition temperature is close to constant and ranges from − 77 °C to -78 °C. The degradation temperatures of all compounds exceed 250 °C. An increase in the concentration of oligodiol nitro groups from 0% to 2.02% led to a more than twofold increase in both the tensile strength and the adhesion strength to the aluminum substrate, the values being from 0.4 MPa to 0.93 MPa and from 0.15 MPa to 0.41 MPa, respectively.