Modification of poly(L-lactic acid) with L-lactic acid / citric acid oligomers

Abstract

The surface modification of polymeric biomaterials can be achieved by surface immobilization of bioactive molecules, increased hydrophilicity, and balanced hydrophilicity and hydrophobicity. Poly (L-Lactic Acid) (PLLA) is hydrophobic and possesses no reactive groups in the structure. In the present work, an effort has been made to blend PLLA with functionalized L-lactic acid / citric acid oligomer (PLCA) in order to improve the hydrophilicity of the PLLA. The compatibility of PLLA and PLCA was studied by using differential scanning calorimetry (DSC). The blends were also characterized for their water absorption, contact angle, tensile strength and hydrolytic degradation. The DSC results showed that PLLA/PLCA blends exhibited a single glass transition temperature (Tg), which lies in between that of PLLA and PLCA thus asserting compatibility at the molecular level. The studies on water absorption, contact angle and hydrolytic degradation showed that addition of PLCA to PLLA enhanced the hydrophilicity of PLLA.