Cellulose-Reinforced Starch Biocomposite: Optimization of the Effects of Filler and Various Plasticizers using Design-Expert Method

In this study, the effect of cellulose as a reinforcement agent and different ratio of glycerol/sorbitol as plasticizers to improve properties in starch biocomposite are optimized with Design-Expert method for the first time. Thermoplastic starch granule is produced with plasticized and cellulose-reinforced starch by a twin extruder. After conditioning, the starch granule, is molded into sheet using a hot press with thick plates. Dynamic mechanical thermal analysis show that cellulose increases the glass transition temperature to 120 degrees C. Optimum point of the starch composite obtained by Design-Expert software 7.1.5, is run with 5 wt% cellulose, 17.5 wt% glycerol and 17.5wt% sorbitol that has water vapor permeability value equally of 7.81E-10g s(-1) m(-1) Pa-1, tensile strength of 0.85 MPa, Young ' s modulus equally of 377.65 MPa, and elongation at break of 7.08%. Field emission scanning electron microscopy of the optimized biocomposite shows uniform distribution of cellulose in the matrix. Hydroxyl stretching vibrations at 3286 cm(-1) is a result of new hydrogen bonding between cellulose and starch molecules and peaks at 3366 and 1702 cm(-1) are attributed to glycerol and sorbitol, respectively in the Fourier transform infrared spectra.

Automated summary

The performance of starch biocomposite is enhanced by optimizing the ratio of plasticizers and using cellulose as a reinforcement agent. The optimized composite shows excellent water vapor permeability, high strength, and good toughness.