The purpose of this study is to improve the performance properties of K-carrageenan (K-CRG) by utilizing nanosilica (NSI) as the reinforcing agent. The composite films were prepared by solution casting method. NSI was added up to 1.5% in the K-CRG matrix. The prepared films were characterized for mechanical (tensile strength, tensile modulus, and elongation at break), thermal (differential scanning calorimetry, thermogravimetric analysis), barrier (water vapour transmission rate), morphological (scanning electron microscopy), contact angle, and crystallinity properties. Tensile strength, tensile modulus, and crystallinity were found to have increased by 13.8, 15, and 48% whereas water vapour transmission rate was found to have decreased by 48% for 0.5% NSI loaded K-CRG composite films. NSI was found to have formed aggregates for concentrations above 0.5% as confirmed by scanning electron microscopy. Melting temperature, enthalpy of melting, and degradation temperature of K-CRG increased with increase in concentration of NSI in K-CRG. Contact angle also increased with increase in concentration of NSI in K-CRG, indicating the decrease in hydrophilicity of the films improving its water resistance properties. This knowledge of the composite film could make beneficial contributions to the food and pharmaceutical packaging applications. 1. Introduction Biopolymers are the polymeric materials obtained from renewable agriculture by-products, waste of food processing industry, and other natural resources (animals, plants, and algae). They are attracting considerable attention as potential replacement for petroleum based plastics due to the increased consciousness for sustainable development. Biopolymers maintain the carbon dioxide balance after their degradation and are readily biodegradable, which will save energy on waste disposal. However, limited performance and high cost of these materials are restricting their competitiveness to traditional thermoplastics. One way to enhance the material properties and to broaden the possible applications for biopolymers is to produce nanocomposites using it [1]. K-carrageenan (K-CRG) is a generic name for a family of polysaccharides, obtained by extraction from certain species of red seaweeds. K-CRG is a water-soluble biopolymer (at elevated temperature) with a linear chain of partially sulphated galactans, which presents high potential as a gel-forming material [2]. Structure of K-CRG is shown in Figure 1. Figure 1: Chemical structure of K-carrageenan. Nanosilica (NSI) filled polymer matrix composites have received
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