Blending cellulose with polyethylene-co-acrylic acid in alkaline water suspension

Abstract

Alkaline solutions of cellulose and polyethylene-co-acrylic acid (PE-co-AA) were mixed in order to prepare homogeneous cellulose/PE-co-AA blends. Different mixing methods were tested and the evolution of solutions was characterized by rheological methods and optical microscopy. In addition to the solution stage studies, the precipitated dry blends were characterized by Differential Scanning Calorimetry, Scanning Electron Microscopy, Fourier Transform Infrared and Dynamic Mechanical Analysis. Mixing the solutions led to the formation of a suspension, consisting of PE-co-AA particles dispersed evenly throughout the cellulose solution. Based on the conducted studies, it became clear that a uniform quality and the best mixing were attained with a method in which the suspension was frozen and melted between the mixing. In dry blends the polymers were found to be mixed on 1 lm scale, and the crystallization temperature of the PE-co-AA phase was increased *6°C due to the nucleation ability of the cellulose phase.

Cellulose/acrylic acid copolymer blends for films and coating applications

“…Figure (b,c) T C = 69°C]. This same phenomenon was observed in the earlier studies (Saarikoski et al and Lipponen et al) which clearly indicated that the polymers were mixed. Rigid/solid cellulose was able to act as a strong nucleation agent for the molten PE ‐co‐ AA phase during the cooling.…”

“…This freeze–melting method between the mixing steps was done in order to dissolve any cellulose which may have gelled during mixing. The effect of this procedure is explained in more detail in an article by Saarikoski et al The blending process is presented in Figure . The polymer compositions of the blend dispersions are represented in Table .…”

“…The advantage of PE ‐co‐ AA is that when the polymers, for example, cellulose (for instance in NaOH/ZnO solvent) and PE ‐co‐ AA are in an alkaline water phase, they precipitate simultaneously by acidic treatment. The blending of cellulose with PE ‐co‐ AA is introduced in articles by Saarikoski et al and Lipponen et al…”

“…Finally, the surface coating approach was used to prepare barrier coatings in a laboratory scale and the barrier properties of the coated paperboards were measured and evaluated. Previous studies by Saarikoski et al and Lipponen et al have proved that the solution mixing procedure is an effective and easy way of preparing blends from dissolved cellulose and PE ‐co‐ AA. Dissolved cellulose with its dense and crystalline structure when regenerated, has potential especially in textile fiber applications .…”

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

“…The EAA polymer was selected mainly due to it being insoluble in water and having the ability to form a stable aqueous dispersion. Also, this modified polyethylene had previously shown good adhesion and compatibility with regenerated cellulose (Saarikoski et al 2012). Composites with up to 70 vol% dry content CNF could be made.…”