Calcium alginate powder increased thermo-compressed sodium-alginate film strength by 208%
Seaweed-derived alginate is biodegradable and biocompatible, but sodium-alginate films are mechanically weak. With glycerol plasticizer, calcium-alginate powder at 2.5-20 wt% was added before thermo-compression. SEM/EDS indicated good interfaces and moisture declined with CA content. At 20 wt%, tensile strength reached 11.7 MPa and modulus 234.7 MPa, increases of 208% and 907% over unfilled SA, showing effective reinforcement by an ionically distinct alginate filler.