Synthesis and characterization of novel biocompatible palm oil-based alkyds

Novel alkyds of short, medium, and long oil length were synthesized using a two-stage alcoholysis-polyesterification method from bio-sourced starting materials. Alcoholysis reaction mixtures of palm kernel oil and glycerol underwent transesterification to convert triglycerides to monoglycerides within 3h. Kinetic studies showed that the polyesterification reaction rates obeyed second order kinetics up to 15min, followed by chain branching and crosslinking. The alkyd chemical structure was confirmed by nuclear magnetic resonance and Fourier Transform infrared spectroscopy. Gel permeation chromatography revealed that the average molecular weight of the alkyds was confined to < 2,000Da which is advantageous for the production of nanoscale drug carriers. Differential scanning calorimetry showed that the alkyds possess low glass transition temperatures within a very narrow range of -49.3 degrees C-52.7 degrees C. Thermogravimetric analysis revealed good thermal stability with alkyd degradation occurring above 200 degrees C. Cell viability assay confirmed that the alkyds were non-toxic to 3T3 mouse fibroblasts following exposure of cell cultures for 24h to solutions of concentration ranging from 3 to 100g/mL. These findings highly recommend consideration of the novel, bio-sourced alkyds for pharmaceuticals manufacture and controlling drug delivery. Practical applications: A family of short, medium, and long oil length alkyds was synthesized as novel biomaterials from fully bio-sourced and renewable starting materials. The alkyds are characterized by molecular weights below 2,000Da, low T-g around -50 degrees C and high thermal stability. The alkyds to exhibit favorable biocompatibility as demonstrated by non-toxicity towards to 3T3 mouse fibroblasts in cell culture. Thus the novel bio-sourced alkyds offer significant potential as excipients for pharmaceuticals manufacture and controlling drug delivery.