Investigations on rheological and mechanical behavior of poly(3‐Hydroxybutyrate)/cellulose nanocrystal based nanobiocomposites

Abstract

The work focused on the formation of percolation network by cellulose nanocrystals (CNCs) in poly(3-hydroxybutyrate) (PHB) matrix, which affects the rheological and mechanical properties of the polymer. Rheological investigations revealed the formation of a percolation network in the fabricated PHB/CNC films with a percolation threshold at a CNC loading of approximately 2 wt%. This observation was further confirmed by both mechanical analysis and modeling studies using Halpin-Kardos and Ouali models. The tensile modulus of the PHB/CNC films was found to be significantly higher (by 58%) than pristine PHB, leading to toughened and more flexible films. Fractured morphology showed the formation of bridge between the CNC and PHB matrix. The rheological parameters (linear and non-linear) were studied in detail to understand the viscoelastic properties of PHB/CNC nanocomposites. Rheological analysis was conducted over a wide range of temperature, and was coupled with differential scanning calorimetry measurements to examine the effect of temperature on the elastic modulus of the nanobiocomposites, especially near the crystallization temperature. The present study is expected to provide a better understanding of the effect of CNC dispersion on the structure-property relation of PHB/ CNC nanocomposites. POLYM. COMPOS., 00:000-000, 2015.

Influence of Epoxidized Canola Oil (eCO) and Cellulose Nanocrystals (CNCs) on the Mechanical and Thermal Properties of Polyhydroxybutyrate (PHB)—Poly(lactic acid) (PLA) Blends

“…This increase in properties has been reported to be associated with the efficient dispersion of CNCs, which allows for a high interfacial adhesion between them and the matrix. In agreement with these results, Bhardwaj et al [10,29] have reported an increase in E (from 1321 MPa to 1412 MPa) and σ UTS (from 36 MPa ± 1.4 MPa to 45 MPa ± 1.8 MPa) with a 5 wt % addition of CNCs. In addition, their work concludes that concentrations as low as 2 wt % of CNCs in the PHB matrix could lead to higher improvements in mechanical properties as this allows for better dispersion and intercalation reinforcement into the PHB matrix.…”

“…Cellulose nanocrystals (CNCs)—which can be obtained from an assortment of biomass products such as coconut fibers and wood—have been previously used as reinforcing agents for biopolymers such as PHB, PLA and poly (vinyl alcohol) (PVA), improving their mechanical properties [22,28]. These materials are highly abundant in nature, eco-friendly, and renewable [22,28,29]. Arrieta et al [22] investigated hot-pressed PLA and PLA-PHB blended films (3:1 ratio) with the addition of 5 wt % pristine CNCs material [22].…”

“…Finally, CNCs were explored as additional reinforcing filler, and were added to both neat PHB and PHB/PLA/eCO blends. Based on the previous work of Arrieta et al, CNCs were added at 5 wt % and 10 wt % [29]. The individual and synergistic effects of these blends and additives were studied.…”

Magnetic Cellulose Nanocrystal Based Anisotropic Polylactic Acid Nanocomposite Films: Influence on Electrical, Magnetic, Thermal, and Mechanical Properties

“…In our previously reported studies 58 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 (Table S2). For the perpendicularly oriented samples, the percentage crystallinity improved by ~4% at 3 wt% MGCNC loading.…”

Effects of Cellulose Nanocrystals and Cellulose Nanofibers on the Structure and Properties of Polyhydroxybutyrate Nanocomposites

“…Other researchers [50] stated that under higher CNCs loading, CNCs begin to aggregate in the form of clusters on the surface of the polymer, and the side effects on mechanical properties are more significant.…”