Production and optimisation of biodegradable LDPE packaging films strengthened with inorganic filler through response surface methods using central composite design

The current study emphasis on the optimisation of degradation of starch-blend LDPE films using nanosilica/modified nanosilica as a property-enhancing filler in order to establish an optimal composition used as a biodegradable packaging film. Weight loss and tensile and tear strength loss were used to determine the individual influence of the essential parameters defining degradability. The Central Composite Design (CCD) approach of Response Surface Methodology was used to optimise the process parameters. The obtained equation for film degradation is quadratic in nature and significant for the process, according to an ANOVA (analysis of variance) study. The addition of starch and modified nanosilica content in the matrix by 60% and above 0.6 g (1.5%) reduces the tensile and tear strength from 19.057 N/mm(2) to 3.64 N/mm(2) and 189.041 N/mm to 27.36 N/mm respectively, however increases the Young's modulus and stiffness to 582.76 MPa and 33654.62 N/m. The optimum composition of starch, LDPE and modified nanosilica was found to be 32, 8 and 0.6 g, respectively, showing an enhanced stiffness, tear strength and Young's modulus of 29591.84 N/m, 155.5 N/mm and 464.25 N/mm(2) along with induced biodegradability of 13.08% under garden soil and 12.07% under vegetable waste.