Acetylation of wheat straw holocellulose for a biodegradable film

Holocellulose extracted from wheat straw was acetylated and used to prepare biodegradable composite film. An efficient catalytic system for the acetylation of holocellulose was explored by evaluating the influence of type and the amount of catalyst on the degree of substitution (DS) of acetylated holocellulose (AHC). The DS of AHC reached 2.16 when using p -toluene sulfonic acid and sulfuric acid as co-catalyst. AHC was further used to prepare composite film in the presence of reinforcer and plasticizer, and the influence of DS value of AHC on the properties of composite film was investigated. The tensile strength, elongation at break and Young’s modulus of the composite film derived from AHC with DS value of 2.16 were 9.51 MPa, 82.66% and 54.43 MPa when using chitosan and polyvinyl alcohol as the reinforcers, sorbitol and glycerol as the plasticizers. The UV-blocking performance and degradation of AHC-based composite film were also performed. It was found that about 90% UV light was absorbed and 59.2% was decomposed after biodisintegrating for 30 d. The excellent comprehensive performance of the AHC-based composite film reveals application prospect of holocellulose in the field of biodegradable materials.