Nanofibrillated cellulose (NFC) reinforced polyvinyl alcohol (PVOH) nanocomposites: properties, solubility of carbon dioxide, and foaming

Abstract

Polyvinyl alcohol (PVOH) and its nanofibrillated cellulose (NFC) reinforced nanocomposites were produced and foamed and its properties-such as the dynamic mechanical properties, crystallization behavior, and solubility of carbon dioxide (CO 2 )-were evaluated. PVOH was mixed with an NFC fiber suspension in water followed by casting. Transmission electron microscopy (TEM) images, as well as the optical transparency of the films, revealed that the NFC fibers dispersed well in the resulting PVOH/NFC nanocomposites. Adding NFC increased the tensile modulus of the PVOH/NFC nanocomposites nearly threefold. Differential scanning calorimetry (DSC) analysis showed that the NFC served as a nucleating agent, promoting the early onset of crystallization. However, high NFC content also led to greater thermal degradation of the PVOH matrix. PVOH/NFC nanocomposites were sensitive to moisture content and dynamic mechanical analysis (DMA) tests showed that, at room temperature, the storage modulus increased with decreasing moisture content. The solubility of CO 2 in the PVOH/NFC nanocomposites depended on their moisture content and decreased with the addition of NFC. Moreover, the desorption diffusivity increased as more NFC was added. Finally, the foaming behavior of the PVOH/NFC nanocomposites was studied using CO 2 and/or water as the physical foaming agent(s) in a batch foaming process. Only samples with a high moisture content were able to foam with CO 2 . Furthermore, the PVOH/NFC nanocomposites exhibited finer and more anisotropic cell morphologies than the neat PVOH films. In the absence of moisture, no foaming was observed in the CO 2 -saturated neat PVOH or PVOH/NFC nanocomposite samples.

Cellulose nanofibril-reinforced composites using aqueous dispersed ethylene-acrylic acid copolymer

“…The method of solvent casting CNF together with a water-soluble polymer is known to yield a well dispersed composite with excellent mechanical properties (Sehaqui et al 2011;Srithep et al 2012). However, the use of a water-soluble matrix polymer makes the resulting composite moisture-sensitive.…”

Nanofibrillated cellulose, poly(vinyl alcohol), montmorillonite clay hybrid nanocomposites with superior barrier and thermomechanical properties

“…Among the various polymer matrices into which nanoscale cellulose has been incorporated, poly(vinyl alcohol) (PVA) has become one of the most widely studied and promising . PVA is one of the most important polymers used in industrial applications due to its excellent thickening, film forming, emulsifying, adhesive, odorless, and nontoxic properties .…”

“…In addition, MMT is well known to enhance the thermal stability and degradation behavior of polymer matrices . This is an important consideration, given the poor thermal stability of NFC and the negative impact it has on the thermal stability of PVA .…”

Injection molding and characterization of polylactide stereocomplex

“…12 displays the tan d curves. The area underneath the tan d peak represents the damping ability of the material; that is, the material's ability to absorb and dissipate energy [32,33]. As can be seen in Fig.…”