Hybrid Filaments from Biomass: Engineering of Alginate Properties with Maleic Anhydride Grafted Linseed Oil.

Linseed oil was graft modified with maleic anhydride and introduced into alginate by co-extrusion, producing alginate hybrid filaments. A straightforward grafting of maleic anhydride onto the oil backbone produced the modified oil. Additional esterification with -dodecanol was also investigated. The structures of the modified oils were verified with 2D-NMR. The modified oil was mixed with alginate and extruded into CaCl, forming thin filaments with diameters in the 130-260 μm range. The impact of oil integration into the alginate filaments was assessed, with special emphasis on stress-at-break, and compared to values predicted by an empirical model relating the "stress to alginate concentration" ratio to prevailing conditions during filament drawing. Analogous alginate filaments were prepared with hydrochloric-, oxalic- and phytic acid calcium salts for comparison with alginate-oil hybrids to reveal the induced impact, with respect to the composition and charge, on the tensile performance.