Enhanced Interphase Adhesion from Bio-pretreated Straw Fiber in Biodegradable Composite Pot: In-Depth Investigation of Degradation Interphase Behavior

Abstract

Biodegradability of fiber-based bio-pot is not only determined by the properties of individual fiber and resin components but also significantly influenced by the behavior of the fiber−resin interphase. Herein, we fabricated bio-pots by utilizing bio-pretreated straw fiber and keratin-modified resin and clarified the interphase degradation mechanism by fiber and composite pot characterization, respectively. The bio-pots exhibited enhanced mechanical properties and hydrophobicity due to improved interfacial adhesion. However, the pretreatment reduced the hemicellulose content in the fibers from 30.06% to 15.84%, resulting in a decrease in the biodegradation rate of bio-pot. Scanning electron microscope and nano-indentation results elucidated that the reinforcing effect of resin on pretreated fibers diminished the interphase's susceptibility to moisture and soil microbials, leading to decreased mechanical loss during natural degradation (e.g., from degradation rate 44.0% for blank samples to 37.4% for 10 day pretreated fiber-based pots at the modulus). The significance of the results may improve bio-pot environmental sustainability and predict its life cycle through interphase degradation. Additionally, the results demonstrate the great future potential on recycling of waste natural fiber and development of composite bio-pot with controllable biodegradability.