Thermal and crystalline properties of biodegradable PCL/PBAT shape memory blends

In this work, a biodegradable polycaprolactone (PCL)/poly (butyleneadipate- co -terephthalate) (PBAT) shape memory blend was prepared by melt blending. The influence of PBAT on the thermal properties of PCL was investigated by thermogravimetric (TG) measurement, differential scanning calorimetry (DSC), polarized optical microscopy (POM), and X-ray diffraction (XRD) methods. The results of TGA and DSC showed that with the increase of PBAT, thermal properties of the blends were improved. The crystallization test revealed that as the mass fraction of PBAT increased, crystallinity of PCL gradually decreased and its crystal size decreased. The thermal and shear stability of the PCL/PBAT shape memory blend were analyzed. With the increase of PBAT mass fraction, the equilibrium torque of PCL/PBAT shape memory blend increased gradually, from 1.5 to 2.5 Nm, but compared with the balancing torque of pure PCL of 4.56 Nm, both were smaller than it. Finally, taking the melting point as the switch temperature ( T s ) of the blend, the bending test showed that the shape memory fixation rate and recovery rate were 96% and over 80%, respectively. Because of its biodegradability, good thermomechanical properties, low cost, and other advantages, the PCL/PBAT shape memory blend showed a high application issues. Graphical abstract