SYNTHESIS AND CHARACTERIZATION OF BIODEGRADABLE MEDICAL POLYURETHANE FOAM: INFLUENCE OF ISOCYANATES AND POLYOLSMOLAR RATIO

Abstract

In this research, biodegradable medical polyurethane foam was synthesized from biocompatible material that suitable for medical applications. Polycaprolactone diol (PCL) and polypropylene glycol (PPG) was used as soft segment, while butane diisocyanate (BDI) and lysine triisocyanate (LTI) was used as hard segment. Degradability of polyurethane was improved by the addition of chain extender synthesized from DL-lactic acid (LA) and ethylene glycol (EG). Polyurethane was prepared with various polyols molar ratios and type of polyisocyanate.The FTIR spectra showed the functional group of urethane linkage and the disappearance of free isocyanate group in polyurethane structure. The increasing of PPG content result in the decrease of glass transition temperature (Tg), compressive strength except for PU-BDI-30 and PU-BDI-50 while the water adsorption increase with the high PPG content directly affected on the degradation of polyurethane during hydrolytic degradation in phosphate buffer saline (PBS) solution at 60 oC. However, the degradation of polyurethane during enzymatic degradation in PBS with lipase was not showed the significant difference. LTI provided polyurethane with higher Tg, compressive strength and degradability than BDI. The toxicity from degradation product was evaluated using L929 cell with MTT assay, the results demonstrated that synthesized polyurethane foam did not have toxicity.