Mechanical, hydrophobic and thermal properties of an organic-inorganic hybrid carrageenan-polyvinyl alcohol composite film

This paper presents that carrageenan (CG) extracted with ultrasonic assisted alkali treatment has good physicochemical properties like uniform porosity and high gel-strength. After grafting with polyvinyl alcohol (PVA), the CG-PVA film was novel plasticized and strengthened by bio-polyol and common cation (Ca2+ or K+). The bio- plasticizer derived from liquefied lignocellulosic biomass (banana pseudo-stem). The elongation of the composite film is significantly increased by 439.31% when adding 3 wt% bio-polyol. Compared with calcium ion, potassium ion is more effective on promoting copolymer chains helix transition and up to 44.30 MPa higher tensile strength was obtained. MR analysis verifies the crosslinking reaction among frameworks of composite films. SEM characterization and contact angle measurement indicate that surface roughness of the hybrid film increases because of CaCO3 deposition caused by Ca2+ reacted with CO2 in the air or artificial produced. TG results show that the thermal stability of the hybrid film is also improved. The renewable and degradable organic -inorganic hybrid film has potential for packaging applications.