The effect of the Mw of PEG in PCL/CA blends

The thermal and mechanical properties of blends of poly(epsilon-caprolactone) (PCL) with cellulose acetate (CA) (PCL/CA) in different proportions (100/0, 80/20, 60/40, 40/60, 20/80 and 0/100 wt%) with or without 10 wt% of poly(ethylene glycol) (PEG 400 and PEG 1500) were investigated by differential scanning calorimetry and tensile property measurements, respectively. The morphology of the materials was also studied by scanning electron microscopy (SEM). The addition of PEG increased the melting temperature (T-m) of PCL and CA in all formulations, except for pure PCL, and also increased the crystallinity of pure PCL and its blends, except for the 40/60/PEG 400 and 20/80/PEG 400 blends. SEM showed phase separation of the polymers. PEG reduced the tensile strength and elongation at break of pure PCL, but increased the tensile strength of blends containing >= 60% of CA and decreased the Young's modulus of all materials. (c) 2005 Elsevier Ltd. All rights reserved.