Хорижий лингвистика ва лингводидактика 3-jild 7-son (2025) · 105-111-betlar
EFFECT OF 1,4-BUTANEDIOL CHAIN EXTENDER ON THE REACTION MECHANISM OF POLYURETHANE FORMATION
Azizkulova, Shakhnoza, Азизкулова, Шахноза, Azizqulova, Shaxnoza
Annotatsiya
This study investigates the polymerization mechanism of 1,4-butanediol, used as a chain extender in the synthesis of polyurethane based on 4,4′-methylenediphenyl diisocyanate (4,4′-MDI), as well as the effect of the diisocyanate concentration on the macromolecular structure and physicomechanical properties of the polymer. During the reaction, the hydroxyl (–OH) groups of 1,4-butanediol react with the isocyanate (–NCO) groups of 4,4′-MDI to form urethane (–NHCOO–) linkages, resulting in polymer chain extension, an increase in the content of hard segments, and improved phase organization of the polymer structure. The effects of 1,4-butanediol (3–8 wt%) and 4,4′-MDI (60–75 wt%) on the polymerization kinetics, macromolecular chain growth, and crosslink density were systematically evaluated. The results demonstrated that compositions containing 4–6 wt% 1,4-butanediol and 68–70 wt% 4,4′-MDI promoted the formation of a homogeneous polyurethane macromolecular structure, providing high mechanical strength, optimum elasticity, and excellent thermal stability. Deviations from these composition ranges resulted in an increased content of residual isocyanate (–NCO) groups, non-uniform formation of the three-dimensional polymer network, and increased brittleness of the material. These findings demonstrate that optimizing the contents of the chain extender and diisocyanate is an effective approach for controlling the molecular architecture and enhancing the performance characteristics of polyurethane materials.
Smart GridsArtificial IntelligenceRenewable Energy IntegrationOptimization TechniquesDistributed Generation
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