SYNTHESIS OF THERMOPLASTIC POLYURETHANE USING AROMATIC DIOLS AS A CHAIN EXTENDER AND DEVELOPMENT OF ADHESIVE COMPOSITIONS BASED ON IT

Thermoplastic polyurethane based on oligobutyleneglycoladipinate, 4,4'-diphenylmethanediisocyanate and a chain extender has been synthesized, as which it is proposed to use aromatic diol - 2,2-bis-[4-(2-hydroxyethoxy)phenyl]propane. The synthesis was carried out in a one-step method with a ratio of reagents providing a lack of isocyanate groups. The final product was a linear copolymer with terminal hydroxyl groups. To compare properties using a similar technology, a thermoplastic was obtained in which the role of the chain extension was performed by aliphatic diol - 1,4-butanediol. The sample obtained with the participation of aromatic diol is amorphous, low-modulus and there is no residual deformation after rupture. The use of aliphatic diol leads to the formation of a crystallized high-modulus polymer with high residual deformation and hardness. The observed differences are associated with the introduction of side methyl groups and simple ether bonds into the structure of a rigid polymer block formed by an aromatic diol. The latter violate the ordering of the packaging of macromolecules and increase their ability to elastic recovery. In addition, the content of aromatic fragments in the hard block increases due to the use of aromatic diol. They contribute to the amorphization of the polymer, increase its strength, and also increase the temperature of the beginning of destruction and the coke residue. At the same time, the thermoplastics under discussion are inferior to the analog synthesized using aliphatic diol in terms of temperatures corresponding to the half-life of the decomposition stage and the completion of the decomposition stage. This is due to the presence of in the hard block of the first, relatively non-thermally stable simple ether bonds. On the basis of the proposed thermoplastic, a two-component adhesive has been developed, which, in terms of bonding strength, surpasses household adhesives, which include polyurethane thermoplastic obtained using aliphatic diol. For citation: Bakirova I.N., Mineeva T.A. Synthesis of thermoplastic polyurethane using aromatic diols as a chain extender and development of adhesive compositions based on it. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 11. P. 106-113. DOI: 10.6060/ivkkt.20246711.7040.