Biodegradation of low-density polyethylene film/plasticized cassava starch blends with central composite design for optimal environmental pollution control

The present study investigated the optimization of biodegradation parameters of low-density polyethylene (LDPE) film/plasticized cassava starch (PCS) blends for optimal environmental pollution control. Six sample blends, 0- 50 wt.% of PCS were produced at the ratios of (0:100, 1:9, 1:4, 1:2.3, 1:1.5 & 1:1) by varying composition of LDPE film and PCS through solvent casting method. Central Composite Design (CCD) of Response surface methodology (RSM) was utilized to optimize the process parameters of concentration and time that resulted in percentage weight loss, elongation at break, tensile and tear strengths (response). Analysis of variance (ANOVA) revealed that the equation obtained for biodegradation is quadratic and hence significant for the process. Addition of 50 wt.% of PCS to the blend reduced the tensile strength from 15.08 - 5.25 MPa, tear strengths from 164.13 - 82.67 N/mm and elongation at break from 18.93 - 9.32 mm, while water absorption was typical of Fickian behavior. Optimal biodegradation of 12.59% at parametric conditions of 43 wt.% PCS and 66 days via RSM was achieved which conforms with a minimum requirement of 12% degradation at 2 months soil burial by NF U52-001 standard. The produced films were characterized by Furrier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) analysis. From the statistical analysis, the optimum biodegradation (12.59%) was achieved at 43 wt.% PCS concentration. As a result, the optimized conditions obtained from this study propose that a 43 wt.% optimal concentration of bio-filler is required for excellent mechanical properties with improved biodegradation for sustainable environmental pollution control.