The effect of polyamide and polyether blocks' length on the structure and properties of poly[(tetramethylene terephthalate)-block-(oxytetramethylene)-block-(lauro- lactam)] elastomer

The ternary multiblock system--terpoly(ester-b-ether-b-amide) TPEEA with the following chemical structure: poly[(tetramethylene terephthalate)-block-(oxytetramethylene)-block-(laurolactam)] marked as-(PBT-b- PTMO-b-PA12)- sub n has been obtained. This is a system in which the third component, PBT block in this case, characterized with properly chosen molecular weight is dissolved in PA12 blocks hard phase and partially dissolved in PTMO blocks soft phase. The effect of the changes of PA12 and PTMO blocks lengths on the structure and phase separation of TPEEA obtained has been determined with using DSC, DMTA and WAXS methods. The significant effect of intermediate phase on the elastomer characteristics as well as important influence of this phase composition on the thermal properties of the continuous phase and separation degrees of hard and soft phases have been confirmed. It has been stated the composition and part of intermediate phase determine many application features of TPEEA and first of all decide about high flexible properties of the product. It has been proved that PBT as a third component introduced into the diblock system (PA-b-PTMO) sub n in some conditions (M sub nPA12 > 2000, 1000 < M sub nPTMO < 1400, DP sub PBT < 7) plays a role of the elastomer structure stabilizer as a compatibilizer on the domain--matrix border.