Improved Barrier Properties of Alkylated Graphene Oxides/Poly(vinyl alcohol) Composite Films Crosslinked with Dialdehyde Cellulose Nanocrystals

Polymer/clay composites are an innovative class of materials. In this study, we present a facile method for the preparation of biodegradable and robust PLA/organomodified montmorillonite (OMMT) composite films with excellent gas barrier performance. When the design of PLA/OMMT composite films, in addition to making OMMT have good intercalation effect in the matrix, the compatibility of intercalating polymer and matrix should also be considered. In this work, two polymers with high gas barrier properties, namely poly(vinyl alcohol) (PVA) and ethylene vinyl alcohol copolymer (EVOH), were selected to intercalate OMMT. The morphology and microstructures of the prepared PLA/PVA/OMMT and PLA/EVOH/OMMT composites were characterized by the X-ray diffraction measurement, scanning electron microscopy, and differential scanning calorimetry. It was shown that the good dispersibility of PVA in the PLA matrix, rather than the intercalation effect, was responsible for the improved gas barrier and mechanical properties of PLA/PVA/OMMT composite. The elongation at break increases from 4.5% to 22.7% when 1 wt % PVA is added to PLA/OMMT. Moreover, gas barrier of PLA/PVA1/OMMT measured as O2 permeability is 52.8% higher than that of neat PLA. This work provides a route to intercalate OMMT interlayer with high gas barrier polymers and thus can be a useful reference to fabricate PLA/OMMT composites with improved gas barrier and mechanical properties. A comparison of oxygen permeabilities with existing commercial packaging films indicates that the biodegradable PLA/PVA/OMMT may serve as a viable substitute for packaging film applications.

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Crosslinked poly(vinyl alcohol) composite films with cellulose nanocrystals: Mechanical and thermal properties

Journal of Applied Polymer Science ◽

10.1002/app.45710 ◽

2017 ◽

Vol 135 (3) ◽

pp. 45710 ◽

Cited By ~ 20

Author(s):

Supachok Tanpichai ◽

Kristiina Oksman

Keyword(s):

Thermal Properties ◽

Cellulose Nanocrystals ◽

Vinyl Alcohol ◽

Composite Films ◽

Poly Vinyl Alcohol ◽

Mechanical And Thermal Properties

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Effect of Incorporating Cellulose Nanocrystals from Corncob on the Tensile, Thermal and Barrier Properties of Poly(Vinyl Alcohol) Nanocomposites

Journal of Nanomaterials ◽

10.1155/2013/289641 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 33

Author(s):

Hudson Alves Silvério ◽

Wilson Pires Flauzino Neto ◽

Daniel Pasquini

Keyword(s):

Cellulose Nanocrystals ◽

Vinyl Alcohol ◽

Average Length ◽

Close Association ◽

Visible Region ◽

Barrier Properties ◽

Nanocomposite Films ◽

Light Transmittance ◽

Poly Vinyl Alcohol ◽

Vapor Permeability

The effect of incorporating cellulose nanocrystals from corncob (CNC) on the tensile, thermal, and barrier properties of poly(vinyl alcohol) (PVA) nanocomposites was evaluated. The CNC were prepared by sulfuric acid hydrolysis at 45°C for 60 minutes, using 15 mL of H2SO4(9.17 M) for each gram of fiber. The CNC60presented a needle-shaped morphology, high crystallinity (83.7%), good initial degradation temperature (236°C), average length (L) of210.8±44.2 nm, diameter (D) of4.15±1.08 nm, and high aspect ratio (L/D) of53.4±15.8. PVA/CNC nanocomposite films with different filler loading levels (3, 6, and 9% by wt) were prepared by casting. The ultimate tensile strength (UTS), thermal stability (TS), light transmittance (Tr) and water vapor permeability (Pw) of the nanocomposites were measured. When compared to neat PVA film, the UTS of the nanocomposites improved significantly, by 140.2%,Pwdecreased up to 28.73%, and there were no significant changes in TS. The nanocomposites also showed excellent Tr in the visible region, maintaining substantially equivalent transparency. These improvements in the nanocomposites' properties suggest a close association between filler and matrix, besides indicating that the CNC were well dispersed and adherent to the polymer matrix.

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