Acid functionalized cellulose nanocrystals and its effect on mechanical, thermal, crystallization and surfaces properties of poly (lactic acid) bionanocomposites films: A comprehensive study

Dhar, Prodyut; Bhasney, Siddharth Mohan; Kumar, Amit; Katiyar, Vimal

doi:10.1016/j.polymer.2016.08.028

Cited by 87 publications

(56 citation statements)

References 48 publications

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“…In addition, the strong adhesion occurring at the CNC-polymer interface and the creation of rigid CNC percolating network within the polymer matrix would facilitate an effective stress transfer from the soft polymer matrix to the rigid CNCs, leading to the improvement in the strength and toughness of polymer nanocomposites. Therefore, how to maximally improve the dispersion state, construct strong interfacial adhesion and create percolating network has gained considerable interest in the CNC-reinforced polymer nanocomposite field [16][17][18][19][20]. Consequently, surface modification of CNCs to be compatible or reactive with polymer matrix was inspired.…”

Section: Introductionmentioning

confidence: 99%

Cationic surface modification of cellulose nanocrystals: Toward tailoring dispersion and interface in carboxymethyl cellulose films

Mei

et al. 2016

Polymer

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The present work describes the development of high performance cellulose nanocrystals/carboxymethyl cellulose (CNC/CMC) films through a rational design of CNC surface chemistry. Considering the anionic surface nature of CMC, surface cationization of CNCs was performed in order to build strong interfacial bonding by electrostatic attraction and form uniform dispersion state by electrostatic repulsion. Nanocomposite films were fabricated by dispersing the CNCs and cationically modified CNCs (mCNCs) in CMC matrix through solution casting. The resultant CNC/CMC and mCNC/CMC films were then evaluated in terms of processability, mechanical properties and fracture surface morphology. Results showed that the reinforcing capacity of mCNCs was greatly dependent on its substitution degree. High substitution degree was favorable for obtaining mCNC/CMC film with unifrom dispersion and superior mechanical properties. The observed distinctive reinforcing phenomena from CNCs and mCNCs in CMC matrix were interpreted in terms of dispersion state and interfacial bonding based on the fracture surface morphology.

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Section: Introductionmentioning

confidence: 99%

Cationic surface modification of cellulose nanocrystals: Toward tailoring dispersion and interface in carboxymethyl cellulose films

Mei

et al. 2016

Polymer

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“…The complex viscosity dropped rapidly during the first 15 min; the molecular weight of PLA resin usually decreases during processing due to thermal degradation as reported by others [23,[56][57][58][59]. On the other hand, the complex viscosity of PLA/CNC nanocomposites showed lower values than PLA sample suggesting that CNC promoted polymer degradation during the processing due to the lower thermal stability of CNC; in fact, sulfate groups on the CNC promote the degradation of the PLA as reported by others [60,61]. It was noticed that the CNC concentration has a slight effect on the viscosity decrement.…”

mentioning

confidence: 60%

Production and Modification of Cellulose Nanocrystals fromAgave tequilanaWeber Waste and Its Effect on the Melt Rheology of PLA

Pech-Cohuo

Canché‐Escamilla

Valadez-González

et al. 2018

International Journal of Polymer Science

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The production and surface modification of cellulose nanocrystals (CNC) from Agave tequilana Weber waste (ATW) and their effect on the melt rheology of PLA were investigated. For that, CNC were obtained from ATW residues by acid hydrolysis and grafted with 2-ethyl hexyl acrylate (2-EHA) to promote compatibility with nonpolar polymers, such as PLA. The morphology of CNC occurred as rods, spheres, and the so-called porous network observed by scanning electron microscopy (SEM) and electron transmission microscopy (TEM), and the crystallinity of the cellulose fibers was ~73% and increased up to ~94% for CNC followed by X-ray diffraction (XRD). The acid hydrolysis and alkali extraction process produce changes on the native cellulose type I from ATW bagasse resulting in a mixture of cellulose type I and II and was preserved after CNC isolation and surface grafting. Polymer grafting was assessed using Fourier-transform infrared spectroscopy (FTIR) and X-ray electron spectroscopy (XPS). Upon surface modification, the grafted CNC presented better thermal stability than CNC pristine evaluated by thermogravimetric analysis (TGA), and the surface energy of the CNC was decreased which could promote CNC dispersion within polymers. Both pristine and surface modified CNC were melt mixed with PLA to produce nanocomposites at different concentrations of CNC. Dynamic time sweep tests showed that the introduction of CNC and CNC/2-EHA decreased the complex viscosity of PLA due to polymer degradation during compounding.

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“…Cellulose fibers are subjected to strong acid hydrolysis to break down the long cellulose polymeric chain into smaller dimensions. Sulfuric and hydrochloric acids are extensively used for CNC preparation, but to a minor extent phosphoric and hydrobromic acids are also reported for such purposes. When the CNCs are prepared by hydrolysis in hydrochloric acid, their ability to disperse in water is limited, and their aqueous suspensions tend to flocculate .…”

Section: Introductionmentioning

confidence: 99%

“…The filter paper Whatman 1 is by far the most common source for isolating CNCs because it is made of almost pure cotton cellulose. Other grades have problems with impurities and are not so adequate for high‐quality materials applications.…”

Section: Introductionmentioning

confidence: 99%

Office waste paper as cellulose nanocrystal source

Orue

Santamaria‐Echart

Eceiza

et al. 2017

J of Applied Polymer Sci

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Cellulose nanocrystals (CNC) are isolated from office waste paper using an alkali solution and a subsequent acid hydrolysis process. The Fourier transform infrared spectroscopy and X-ray diffraction (XRD) results demonstrate that ink and fillers used in the papermaking industry are almost totally removed after alkali treatments. The XRD results show that CNCs obtained after 2 wt % NaOH solution treatment and a subsequent hydrolysis process exhibit only a cellulose I crystalline structure, and the crystallinity index value increases around 42% with respect to initial office waste paper. Nevertheless, CNCs obtained after 7.5 wt % NaOH solution treatment and a subsequent acid hydrolysis process show a mixture of cellulose I and cellulose II polymorphs. The thermal analysis shows that the CNCs obtained after 7.5 wt % NaOH solution treatment and a subsequent acid hydrolysis process are thermally less stable than other samples, suggesting that the cellulose chains could depolymerize into low molecular weight sugar compounds. Even though the atomic force microscopy images confirm the presence of CNCs, the optical images show that some cellulose microfibers still maintain their structure.

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Acid functionalized cellulose nanocrystals and its effect on mechanical, thermal, crystallization and surfaces properties of poly (lactic acid) bionanocomposites films: A comprehensive study

Cited by 87 publications

References 48 publications

Cationic surface modification of cellulose nanocrystals: Toward tailoring dispersion and interface in carboxymethyl cellulose films

Cationic surface modification of cellulose nanocrystals: Toward tailoring dispersion and interface in carboxymethyl cellulose films

Production and Modification of Cellulose Nanocrystals fromAgave tequilanaWeber Waste and Its Effect on the Melt Rheology of PLA

Office waste paper as cellulose nanocrystal source

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