Biodegradation Study by Pseudomonas sp. of Flexible Polyurethane Foams Derived From Castor Oil

Abstract

The synthesis and biodegradation of polyurethane foams obtained from environmentally benign processeswere studied.Flexible polyurethane foams based on castor oil modified with maleic anhydride (MACO) were synthesized.The synthesis involved a single-stage process by mixing castor oil/MACO (weight ratios 75:25and 25:75) and 2-4 toluene diisocyanate (TDI) in stoichiometric amount of OH:NCO. The biodegradabilitystudies with cultures of a Pseudomonas sp. strain (DBFIQ-P36) involved incubation periods of 2 months at37 C. Polymers were characterized before and after biodegradation by Fourier Transform InfraredSpectroscopy (FT-IR), INSTRON mechanical tester, and Scanning Electron Microscopy (SEM). The resultsshowed that the addition of MACO produces a considerable increase in the rate of degradation and animportant change in the chemical and morphological structures. This is due to the presence of estergroups that are vulnerable to chemical hydrolysis and enzymatic attack. The eco-toxicity after thebiodegradation was evaluated. Toxic compounds such as primary amines were identified by Gas ChromatographyeMassSpectrometry (GCeMS) in combination with Nuclear Magnetic Resonance (NMR) asdegradation products.