Effect of Lignin Content on the Degradation of the Composite Material Prepared from Thermoplastic Starch and Sugarcane Pith

To investigate the effect of lignin content on the material prepared from thermoplastic starch and sugarcane pith (TPS/BP), individual alkaline and combined acid and alkaline pretreatments were employed to obtain BP with different contents of lignin for preparation of TPS/BP. Degradation by microbial organisms using shaking flask and observation of morphology by using SEM were investigated. The deepen scratch-like structure on the surface of BP was observed, which is possibly due to the removal of lignin. Lignin content was decreased by 15% after pretreatment at 100 °C using 5% NaOH solution. The biodegradability of the resultant TPS/BP was improved by 61.76% after 10 days’ digestion at 30 °C with a rotatory speed of 150 rpm. The biodegradability of TPS/BP with lower lignin content of 4–5% was significantly enhanced, with complete degradation after 10 days’ digestion in shaking flask.