Cellulose acetate synthesized from cold‐sheared cellulose shows improved ability to toughen poly(lactic acid)

Abstract Cellulose acetate (CA), synthesized by solid–liquid acetylation of low crystalline cellulose (LCCell) obtained by cold shearing in a short time under environmentally benign conditions, effectively enhanced the crystallization of poly(lactic acid) (PLA). The composite of PLA compounded with CA from LCCell exhibited higher crystallinity of PLA and flexural modulus than those from pristine PLA. CAs obtained from crystalline and recrystallized cellulose also improved the mechanical strength of PLA by compounding, but their effects were weaker than that of CA from LCCell. The factor of the effectiveness of CA obtained from LCCell is the higher miscibility with PLA originating from the sufficiently released interchain hydrogen bonds in the cellulose fibrils by cold shearing, which allows the dissolution of macroscopic aggregation of the CA chains in the composite.