Castor oil was modified by transesterification with pentaerithritol. In a parallel step, starch was divided into monosaccharide units by glycosylation in order to obtain products with high hydroxyl content. The values of hydroxyl index were measured according to the content of pentaerithritol and starch used in the synthesis. Novel simultaneous interpenetrating polymer networks (SINs) of polyurethane (PU) and poly(methyl methacrylate) (PMMA) in different weight ratios of 100/0, 90/10, 80/20, 70/30, 60/40 and 50/50 were prepared based on polyol-glucosides. The polyurethane network was created by reacting the poliol-glucosides with isophorone diisocyanate maintaining a molar ratio NCO/OH = 1. The PMMA network was synthesized using benzoyl peroxide as initiator and ethylene glycol dimethacrylate as the crosslinker. The SINs were characterized in their mechanical properties, such as Shore A hardness, tensile strength and elongation at break. Thermal stability of SINs was measured using thermogravimetric analysis (TGA). Surface morphology measured using scanning electron microscope (SEM) showed two-phase morphology for all the SINs. SINs based on polyurethane from castor oil modified and poly(methyl methacrylate) show limited compatibility at low concentrations of PMMA, but are totally incompatible at higher concentrations of PMMA.
Castor oil; starch; glycosylation; SINs; poly(methyl methacrylate) (PMMA)
