Effect of fiber surface treatments on the properties of short sisal fiber/poly(lactic acid) biocomposites

Sisal fiber (SF)-reinforced poly(lactic acid) (PLA) biocomposites were prepared from biodegradable PLA and surface-untreated or -treated short SF by melt mixing and subsequent compression molding. It is found that the surface treatments facilitate good adhesion between SFs and PLA matrix, which is consistent with the higher mechanical properties of the treated-SF/PLA biocomposites. Moreover, the surface treatments have similar effects on the biodegradability and water absorption of the biocomposites with the order as following: neat PLA < acetylated SF (A-SF)/PLA biocomposite ≈ silane-treated SF (S-SF)/PLA biocomposite < permanganate-treated SF (P-SF)/PLA biocomposite < mercerized SF (M-SF)/PLA biocomposite < untreated fiber (U-SF)/PLA biocomposite. In terms of overall consideration of the properties, acetylation treatment seems to be the most desirable surface method owing to the maximum tensile strength and water resistance, medium impact strength, and minimum degradability of the A-SF/PLA biocomposite. © 2012 Society of Plastics Engineers