Study On Preparation And Properties Of Pp/Pet/Poe-g-Mah Shape Memory Blends

Because of excellent function, thermally stimulated shape memory polymer has potency in many fields. So recent years, it receives great attention. In this paper, a novel thermostimulative shape memory PP/PET blends with physical cross-linked network were prepared by melt blending with POE-g-MAH as reactive compatibilizer. Effects of POE-g-MAH content on the shape memory effect, mechanical, rhelolgical and thermal properties of PP/PET blends were investigated using scanning electron microscopy (SEM), polarized optical microscopy (POM), differential scanning calorimetry (DSC), mechanical testing machines, HAAKE torque rheometer and capillary rheometer. And the relationships between phase morphology and basic properties of the blends were also discussed.POE chain segment of reactive compatibilizers POE-g-MAH exist a interaction with the PP matrix of PP/PET system, and the MAH chain segment can react with the end-hydroxyl of PET. Therefore, POE-g-MAH is helpful to improve the compatibility of PP/PET blending systems, improve two phase interface bonding, make the PP/PET blends have good comprehensive performance.In the system of PP/PET/POE-g-MAH blends, POE-g-MAH can enhance the interfacial adhesion between PP and PET and improve phase morphological structure. So the shape memory effect and combined mechanical properties of the blends were improved. Furthermore, the blends possessed good thermal property. The experimental results showed that when the blend ratio of PP/PET/POE-g-MAH was90/10/7. the blend possessed the best mechanical and thermal properties. Meanwhile, when the blend ratio was90/10/7, the PP/PET/POE-g-MAH blends exhibited the best shape memory effect at stretch ratio of80%, stretch rate of25mm/min, and recovery temperature of170℃. Moreover, from the shape memory investigation results, a new shape memory mechanism for this type of SMP system was concluded. In this SMP blends, dispersed PET acted as fixed phase whereas continuous PP phase acted as reversible or switch phase. During the deformation process, the droplets of fixed phase keep the original shape, whereas the molecular orientation occurred in reversible phase and internal stress was kept in the system. Consequently, heating up the material and releasing the stress would deform the shape back to the original shape.