Pretreatment and modification of corn straw cellulose and the preparation of its composite by blending with poly(butylene adipate‐co‐terephthalate)

Abstract Blending agricultural residual corn straw (CS) with poly(butylene terephthalate/adipic acid) (PBAT) is beneficial for solving significant environmental and economic issues. However, the high polarity and hydrophobic nature of lignin encapsulating CS cellulose limits its application in composites. Therefore, it is essential to enhance the compatibility between CS and PBAT through modification, aiming to improve interfacial interactions and overall composite performance. In the study, CS was pretreated using UV/TiO₂ photocatalytic oxidation to produce pretreated cellulose (CS‐C). This process removed the majority of lignin and hemicellulose, leading to a higher cellulose content and disruption of amorphous components. Hydrophilic CS and CS‐C cellulose were modified with nano‐TiO₂, named as CS‐M and CS‐CM, respectively. CS‐CM cellulose not only exhibited a higher cellulose content but also demonstrated superior dispersibility. Four types of composites were prepared by blending corn straw cellulose with PBAT. CS‐CM/PBAT exhibited optimal interfacial compatibility at 10 wt% corn straw content. The incorporation of CS‐CM cellulose enhanced the impact strength and significantly improved the bending strength of PBAT. Pretreatment and modification improved the overall mechanical properties, crystallization, and thermal stability of the composite. Moreover, the inclusion of corn straw cellulose promoted the degradation of PBAT, with CS‐C/PBAT and CS‐CM/PBAT experiencing weight losses of 90.27% and 87.55%, respectively, after 6‐days of hydrolysis by Fusarium solani cutinase. Highlights The cellulose content of corn straw (CS) was increased by UV/TiO₂ pretreatment. Mechanical properties of PBAT were enhanced by blending with TiO₂‐modified CS. Blending PBAT with TiO₂‐modified CS enhanced its enzymatic degradation.