Characterization of PVA and Chitosan/PVA Blends Prepared from Aqueous Solutions of Various Na₂SO₄ Concentrations

Abstract

Uniplaner orientation of a particular crystal plane along the surface of a film was investigated for poly (vinyl alcohol) (PVA) film prepared by a coagulation bath with concentrated aqueous solution containing 100 ∼ 300g of Na2SO4 against 1 ℓ of water. The orientation distribution functions of the three crystallographic principal axes of the dried films were obtained by the X‐ray diffraction technique. The same treatment was carried out for the films prepared by stretching biaxially of the fresh gel and then by drying the resultant fresh gel. The very high preferential orientation of the crystal chain axes and amorphous chain segments could be realized by the biaxially elongation. Accordingly, the techniques were applied to the biaxially stretching of chitosan and PVA blend films with high Young's modulus. The planer orientation of the chain axes of chitosan and PVA crystallites could be confirmed. The morphology of the film surface was estimated by measurements of contact angle and electron spectroscopy for chemical analysis. The results suggested that the admixture of chitosan decreases wet ability of the specimen and this tendency was slightly enhanced by the biaxially elongation.

Influence of Plasticizer Type on the Properties of Polymer Electrolytes Based on Chitosan

“…Figure shows X-ray diffraction patterns obtained for the chitosan and chitosan-based electrolytes having different compositions. The crystallization degree of 65% of chitosan was obtained from X-ray measurements (Figure a) using the following equation X % = ( I cr − I am / I cr ) × 100 % where I cr is the intensity of the crystalline diffraction peak at 2θ = 20.1° and I am is the intensity of the amorphous broad band centered at 2θ = 10.9°. , These results are similar to those presented by Nunthanid et al and by Drambei et al, who obtained blends of chitosan with PVA.…”

Nanocomposites of PVA/cellulose nanocrystals: Comparative and stretch drawn properties

“…These 2θ peaks at about 20° correspond to the semi‐crystalline nature of PVA. [ 19 ] As reported by Drambei et al, [ 20 ] the crystal structure of PVA diffracts at 2θ angles 19.3, 20.0, and 22.9° respectively for the (110), (1 0), and (200) planes. The planes that appeared at maximum peaks in Figure 5 for all samples can be considered (1 0).…”