Electron beam synthesis and characterization of poly(vinyl alcohol)/montmorillonite nanocomposites

Abstract

Poly(vinyl alcohol) (PVA)/montmorillonite clay (MMT) nanocomposites in the form of films were prepared under the effect of electron beam irradiation. The PVA/MMT nanocomposites gels were characterized by Xray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and mechanical measurements. The study showed that the appropriate dose of electron beam irradiation to achieve homogeneous nanocomposites films and highest gel formation was 20 kGy. The introduction of MMT (up to 4 wt %) results in improvement in tensile strength, elongation at break, and thermal stability of the PVA matrix. In addition, the intercalation of PVA with the MMT clay leads to an impressive improved water resistance, indicating that the clay is well dispersed within the polymer matrix. Meanwhile, it was proved that the intercalation has no effect on the metal uptake capability of PVA as determined by a method based on the color measurements. XRD patterns and SEM micrographs suggest the coexistence of exfoliated intercalated MMT layers over the studied MMT contents. The DSC thermograms showed clearly that the intercalation of PVA polymer with these levels of MMT has no influence on the melting transitions; however, the glass transition temperature (T g ) for PVA was completely disappeared, even at low levels of MMT clay.

Evaluation of the potential of polymeric carriers based on chitosan‐grafted‐polyacrylonitrile in the formulation of drug delivery systems

“…To examine the effects of grafting reaction, hydrolysis of the grafted products, and release medium on drug release, the in vitro release studies were carried out in 300 mL of both simulated gastric fluid (SGF) (0.1 M HCl/KCl, pH = 1.2) and simulated intestinal fluid (SIF) (0.05 M phosphate buffer, pH = 7.1), as the dissolution medium at 37°C. An aliquot of 2 mL was collected at regular intervals and the amount of MO released was measured colorimetry using visible light‐UV spectrophotometer [Perkin‐Elmer Lambda 3B] in a 1‐cm cell at 520 nm for SGF and 450 for SIF 28–30. Each in vitro release study was performed in triplicate.…”

“…The hydrolyzed and unhydrolyzed chitosan‐ g ‐PAN grafted copolymers were punched into matrix tablet after incorporation with MO, which was used as a drug model due to its availability, ease of estimation, its chemical structure (Scheme ) which may be close to many types of drugs, in addition to the previous use for the same purpose in previous reports 28–32. The release profiles of the drug model MO from the formulated tablets were performed in SGF and SIF media without enzymes.…”

Characterization of Electron Beam Irradiated Poly Vinyl Alcohol/Poly Ethylene Glycol Blends

“…Hydrogen bonds keep together polymer chains, even in the amorphous phase. PVA has been the subject of intensive research because it has many applications in industry and it is of relatively low cost [1][2][3][4][5][6].…”

Preparation and Characterization of Poly Vinyl Alcohol/Poly Vinyl Pyrrolidone/Clay Based Nanocomposite by Gamma Irradiation

“…Figure 1 shows the effect of gamma irradiation dose on the gelation percent of PVA/PVP/clay nanocomposites (PVA/PVP/clay) (60:40) and 1.5% clay. The distribution of clay nanoparticles with the interchain hydrogen bonding between the hydroxyl group of the PVA chains and carbonyl groups of PVP chains would eventually facilitate the exposure of additional sites to gamma irradiation leading to higher gel fractions by the irradiation dose up to 25 kGy due to the formation of insoluble and entangled polymeric network as shown in Figure 1 (12,17). As the radiation dose increases to more than 25 kGy, it can be seen that, the gelation percent decreased.…”