Miscibility and thermal behavior of poly (ɛ-caprolactone)/long-chain ester of cellulose blends

The long-chain cellulose ester (LCCE) cellulose laurate, poly(ɛ-caprolactone) (PCL) and their blends were characterized by tensile strength, Fourier transform infrared spectroscopy (FTIR), dynamic mechanical thermal analysis, thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The compatibility of the blends was investigated and the TEM results showed that PCL tended to disperse as discrete particles in LCCE. FTIR revealed that there were several specific interactions between the chains of PCL and LCCE: the interaction between CH and OC, CO⋯OC or CO⋯OC dipole–dipole interactions. The addition of PCL into LCCE increased slightly the tensile stress at break and the elongation up to 90/10 LCCE/PCL (w/w), which suggested partial compatibility between the polymers. In agreement with this, TGA showed that the compatibility of PCL and LCCE enhanced the thermal stability of LCCE in the blends. Together, these results indicated the existence of intermolecular interactions between the two polymers.