Porous biodegradable blends of poly(L-lactic poly(ε-caprolactone):: polyester acid) and physical properties, morphology, and biodegradation

Poly(L-lactic acid) (PLLA), poly(epsilon-caprolactone) (PCL), and their films without or blended with 50 wt% poly(ethylene glycol) (PEG) were prepared by solution casting. Porous films were obtained by water-extraction of PEG from solution-cast phase-separated PLLA-blend-PCL-blend-PEG films. The effects of PLLA/PCL ratio on the morphology of the porous films and the effects of PLLA/PCL ratio and pores on the physical properties and biodegradability of the films were investigated. The pore size of the blend films decreased with increasing PLLA/PCL ratio. Polymer blending and pore formation gave biodegradable PLLA-blend-PCL materials with a wide variety of tensile properties with Young's modulus in the range of 0.07-1.4 GPa and elongation at break in the range 3-380%. Pore formation markedly increased the PLLA crystallinity of porous films, except for low PLLA/PCL ratio. Polymer blending as well as pore formation enhanced the enzymatic degradation of biodegradable polyester blends. (c) 2006 Society of Chemical Industry.