Abstract
One of the major obstacles for polyhydroxybutyrate (PHB), a biodegradable and biocompatible polymer, in commercial applications is its poor elongation at break (~3%). In this study, the effects of nanocellulose contents and their types, including cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) on the crystallization, thermal, and mechanical properties of PHB composites were systematically compared. We explored the toughening mechanisms of PHB by adding CNCs and cellulose CNFs. The results showed that when the morphology of bagasse nanocellulose was rod-like and its content was 1 wt %, the toughening modification of PHB was the best. Compared with pure PHB, the elongation at break and Young’s modulus increased by 91.2% and 18.4%, respectively. Cellulose nanocrystals worked as heterogeneous nucleating agents in PHB and hence reduced its crystallinity and consequently improved the toughness of PHB. This simple approach could potentially be explored as a strategy to extend the possible applications of this biopolymer in packaging fields.
Highlights
In the past few decades, the negative environmental impacts caused by petroleum-based polymers and the depletion of petroleum resources have been an important issue
Three-layer composite film by an electrospinning coating technique and reported that in comparison with pure PHB, the elongation at break of the multilayer film was increased by 135.7%, and the Young’s modulus and tensile strength were decreased by 11.5% and 35.6%, respectively
The sample was subjected to ultrasonic treatment for 5 min to obtain a uniform nanocellulose suspension (The experimental chart of the best choice of acid hydrolysis temperature, acid hydrolysis time, and acid hydrolysis concentration can be found in the Supplementary Material)
Summary
In the past few decades, the negative environmental impacts caused by petroleum-based polymers and the depletion of petroleum resources have been an important issue. The reinforcing of PHB has been frequently carried out, and natural fibers are always involved due to its biocompatibility and biodegradability [7] As both nanocellulose and PHB are renewable materials, PHB-based biodegradable nanocomposites have great application prospects in the packaging field. Cherpinski et al [24] prepared a PHB/CNF/PHB three-layer composite film by an electrospinning coating technique and reported that in comparison with pure PHB, the elongation at break of the multilayer film was increased by 135.7%, and the Young’s modulus and tensile strength were decreased by 11.5% and 35.6%, respectively. The process optimization of PHB toughening by nanocellulose and its mechanism was evaluated in this paper
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
