Swelling, mechanical and mucoadhesion properties of Mt/starch-g-PMAA nanocomposite hydrogels

Novel mucoadhesive montmorillonite/starch-graft-poly (methacrylic acid) nanocomposite hydrogels (Mt/S-g-PMAA) based on gelatinized wheat starch, an anionic monomer methacrylic acid (MAA), and different amounts of montmorillonite (Mt) as nanoparticles were synthesized according to the conventional grafting reaction mechanism in the aqueous media. The grafting amount of the products (G%) was determined. The formation of Mt/S-g-PMAA was confirmed by FTIR and XRD analyses. The swelling behavior and the erosion characteristics of the Mt/S-g-PMAA were investigated in deionized water, and pH = 5 lactate buffer solution as in vitro vaginal medium at 37 +/- 0,1 degrees C. Mechanical and in vitro mucoadhesion properties of all Mt/S-g-PMAA were also investigated using ewe vaginal mucosa. The results show that adding a higher amount of Mt could effectively increase the mucoadhesion properties of the clay mineral-polymer nanocomposite (CPN) hydrogels. It is then concluded that the 10Mt/S-g-PMAA may be used as alternative highly mucoadhesive CPN hydrogel drug carrier for vaginal route. (C) 2015 Elsevier B.V. All rights reserved

Thermal degradation characteristic of Tetra Pak panel boards under inert atmosphere

Thermal degradation characteristics of Tetra Pak panel boards (TPPB) can be useful to improve usage of such panels as an alternative to wood-based products such as plywood, fiberboard, and particleboard. In the study, samples from the TPBBs manufactured from waste Tetra Pak packages (WTPP) were heated in a nitrogen atmosphere at different heating rates (10, 15 and 20 degrees C/min) using a thermal analysis system. The Coats-Redfern kinetic model was applied to calculate kinetic parameters. The degradation rate equations were then established. In addition, the kinetic compensation effect (KCE) was used to correlate the pre-exponential factor (k(o)) with activation energy (E-a) and the existence of the KCE was accepted. TG-FT/IR analyses were applied to the TPPB degradation and then the FT-IR stack plot was used to analyze gas products (CO2, CH4, HCOOH, and CH3OH). Infrared vibrational frequencies and the micro, crystal structure of the TPPBs were investigated by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) and X-Ray diffraction analysis (XRD), respectively