Comparison of Mechanical Reinforcement Effects of Cellulose Nanofibers and Montmorillonite in Starch Composite

Abstract

Both cellulose nanofibers (CNF) and montmorillonites (MMT) are nanoscale reinforcement fillers that have shown reinforcing effects in polymer nanocomposites. CNFs belong to one‐dimensional nanofibers while MMT is part of two‐dimensional clay platelets, which show difference in shape, size, and composition. This study systematically compares their morphology and dispersion properties in a corn starch (CS) matrix, interactions with the matrix, and the resulting reinforcing effects on the CS matrix. Transparent CS/CNF and CS/MMT nanocomposites comprising up to 7 wt% nanofillers are obtained via solution casting. Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), Scanning Electron Microscope (SEM), and tensile testing, thermogravimetry analysis (TGA), moisture uptake (Mu), and light transmittance (Tr) are used to examine the above‐mentioned properties of CS composites. It is found that the tensile properties, optical transparency, and water barrier properties of CS films are significantly improved whether adding a certain amount of CNF or MMT. However, the tensile strength increment of CS composites reinforced with CNF is slightly higher than that of MMT‐reinforced CS composites due to higher aspect ratio of CNF. From the results, it can be concluded that CNF is highly compatible with starch and can reinforce the starch phase efficiently to prepare green nanocomposite films.

A Comprehensive Review on the Emerging Roles of Nanofillers and Plasticizers towards Sustainable Starch-Based Bioplastic Fabrication

“…The higher decomposition rate was attributed to the aluminium ions in nanoclay, which acted as Lewis acids to catalyse the hydrolysis process [74]. Li et al [61] also reported the improvement of the tensile strength of bioplastic from 48.96 MPa to 64.75 MPa after the addition of 5 wt.% of MMT. One point to note is that susceptibility to agglomeration is the unavoidable problem associated with the utilization of nanofiller in polymers.…”

“…Therefore, ultrasound treatment was employed in the reported studies to disperse the nanofillers in the starch matrix. Homogeneous dispersion of nanofiller in the starch matrix could ensure even transfer of stress between the matrix and the nanofiller, thus enhancing the mechanical properties of polymer nanocomposites [61].…”

“…CNT, GO and carbon black are examples of carbonaceous nanofillers. CNT is widely used as nanofiller in starch-based bioplastic owing to its superior mechanical (high tensile strength and Young's modulus), electrical, magnetic, optical and thermal properties [61]. CNT can be produced by rolling sheets of carbon atoms (graphene) to form either single walled or multi-walled CNTs [33].…”

Effect of hydroxyapatite on physical, mechanical, and morphological properties of starch-based bio-nanocomposite films

“…19 Addition of nanofillers to starch is a strategy to overcome these drawbacks. 20 Nanoparticle size, interfacial area, and aspect ratio of fillers are parameters which determine extent of mechanical properties enhancement upon addition of nanofillers. [21][22][23] Hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 , is the most stable specie of calcium phosphate family regarding human body temperature and pH.…”

“…19 Addition of nanofillers to starch is a strategy to overcome these drawbacks. 20 Nanoparticle size, interfacial area, and aspect ratio of fillers are parameters which determine extent of mechanical properties enhancement upon addition of nanofillers. 21-23…”