Mechanochemical Activation of Carboxy Methyl Cellulose and Its Thermoplastic Polyvinyl Alcohol/Starch Biocomposites with Enhanced Physicochemical Properties

Abstract

Polyvinyl alcohol (PVA) / starch (S) /Carboxy methyl cellulose (CMC) composite films were prepared from PVA, three different loading of CMC and soluble starch aqueous suspensions by casting method in the presence of plasticize containing glycerol. The effects of the CMC addition on the some physical properties of the resulted blend films were investigated. Tensile tests demonstrated positive results from mechanochemical treatment. With the addition of 20% CMC was an increase in the tensile strength and percentage elongation at break. The thermal properties of polyvinyl alcohol (PVA)/Starch(S)/Carboxymethyl cellulose (CMC) blends were investigated by thermogravimetry (TGA) and derivative thermogravimetry (DTG). At least four degradation distinct stages were identified in the PVA/S/CMC blends by means of using TGA, being assigned to the mass loss due to the plasticizer leaching, and to the degradation of the starch, CMC and PVA fractions. The thermal stability of PVA/S/CMC blends is higher than that of PVA/S suggesting that the addition of CMC improved the thermal stability of PVA/S blend. The SEM (Scanning electron microscopy) indicates morphological structure of the polyvinyl alcohol/starch films in the different percent of CMC.