Preparation, Structure and Properties of Urethane-Containing Elastomers Based on Epoxy Terminal Oligomers

Simple and Efficient Synthesis of Oligoetherdiamines: Hardeners of Epoxyurethane Oligomers for Obtaining Coatings with Shape Memory Effect

In this work, new polymers with a shape memory effect for self-healing coatings based on oligomers with terminal epoxy groups, synthesized from oligotetramethylene oxide dioles of various molecular weights, were developed. For this purpose, a simple and efficient method for the synthesis of oligoetherdiamines with a high yield of the product, close to 94%, was developed. Oligodiol was treated with acrylic acid in the presence of a catalyst, followed by the reaction of the reaction product with aminoethylpiperazine. This synthetic route can easily be upscaled. The resulting products can be used as hardeners for oligomers with terminal epoxy groups synthesized from cyclic and cycloaliphatic diisocyanates. The effect of the molecular weight of newly synthesized diamines on the thermal and mechanical properties of urethane-containing polymers has been studied. Elastomers synthesized from isophorone diisocyanate showed excellent shape fixity and shape recovery ratios of >95% and >94%, respectively.

Modified oligoether-diamine synthesis for the preparation of crystallizable polymers based on epoxyurethane oligomers

A modified synthetic method for amino-terminated oligo tetramethylene oxides is presented. Diamines were synthesized via a three-step route from oligo tetramethylene oxide diol with an average molecular weight of 2000. The final step – oligoether-diphthalimide hydrazinolysis – has been improved. The yield of the target product has been shown to be more than 1.5 times higher when the molar ratio of the reacting components was changed. The oligoether-diamine and the reaction intermediates have been identified by 1H and 13C NMR spectroscopy. It has been demonstrated that the synthesized amine can be used as a curing agent for epoxy urethane oligomers. It is shown that the glass transition temperature of the cured elastomers is lower than −70 °C. These elastomers can be recommended for the use in the conditions of the Arctic and the Far North or Far South of the globe.

Synthesis and Study of Physical and Mechanical Properties of Urethane-Containing Elastomers Based on Epoxyurethane Oligomers with Controlled Crystallinity

The influence of the molecular weight of oligoamine, oligoether, and the type of diisocyanate on the physical and mechanical properties of elastomers with urethane hydroxyl hard segments was studied. For this purpose, oligoetherdiamines with molecular weights ~1008 and ~1400 g mol⁻¹ were synthesized by a three-stage method. Epoxyurethane oligomers were synthesized according to a two-step route with an oligodiisocyanate as an intermediate product. A series of 12 elastomers with controlled crystallinity were synthesized from these elastomers and amines. The deformation and strength properties of the elastomers were studied.