Modification of Rice Straw for Good Thermoplasticity via Graft Copolymerization of ε-Caprolactone onto Acetylated Rice Straw Using Ultrasonic-Microwave Coassisted Technology

Developing renewable resources for industrial applications, rather than using severely depleted natural fossil, is the biggest need of recent times. In this regard, rice straw (RS) has already been considered as an alternative material. However, some structural modifications need to be performed to make RS suitable for different applications. The objective of this study was to improve thermoplasticity of RS, required for industrial purposes. Acetylated rice straw-graft-poly(e-caprolactone) (ARS-g-PCL) copolymers were synthesized via ring-opening polymerization (ROP) of e-CL onto ARS in the presence of stannous octoate (Sn(Oct)2), N,N-dimethylacetamide (DMAC), using a rapid and efficient sonochemistry-assisted microwave process. The effects of microwave power, ultrasonic power, reaction time, temperature, and amount of e-caprolactone on grafting percentage (PG) were examined. The sonochemistry-assisted microwave process significantly increased graft efficiency. The optimized conditions for obtaining the ma...