Mariusz Oleksy

Epoxy Resin Composite Based on Functional Hybrid Fillers

A study was carried out involving the filling of epoxy resin (EP) with bentonites and silica modified with polyhedral oligomeric silsesquioxane (POSS). The method of homogenization and the type of filler affect the functional and canceling properties of the composites was determined. The filler content ranged from 1.5% to 4.5% by mass. The basic mechanical properties of the hybrid composites were found to improve, and, in particular, there was an increase in tensile strength by 44%, and in Charpy impact strength by 93%. The developed hybrid composites had characteristics typical of polymer nanocomposites modified by clays, with a fine plate morphology of brittle fractures observed by SEM, absence of a plate separation peak in Wide Angles X-ray Scattering (WAXS) curves, and an exfoliated structure observed by TEM.

A new polyurethane binder providing high green strength of dry-pressed alumina

Abstract The effect of a new polyurethane binder on green strength of dry-pressed alumina bodies was studied. The alumina compacts showed exceptionally high green strength. Depending on binder concentration (1–5 wt.%) the tensile and flexural strength were 1.6-7.0 MPa and 2.0–12.7 MPa, respectively. The high green strength was controlled by polymer–ceramics interactions, as was revealed by IR study. The glass transition temperature of polymer influenced the binder behaviour in ceramic processing. To achieve high green density some residual moisture was needed but then samples had to be dried to obtain high green strength. The binder burnout was characterized by TGA and DTA study in air and in nitrogen. The polyurethane binder had a gradual burnout with a low char residue in both types of atmosphere. The thermal decomposition in air was caused by oxidation reactions, while in nitrogen, the polyurethane binder underwent depolymerization process.

Gloves against mineral oils and mechanical hazards: composites of carboxylated acrylonitrile-butadiene rubber latex.

Resistance to permeation of noxious chemical substances should be accompanied by resistance to mechanical factors because the glove material may be torn, cut or punctured in the workplace. This study reports on glove materials, protecting against mineral oils and mechanical hazards, made of carboxylated acrylonitrile–butadiene rubber (XNBR) latex. The obtained materials were characterized by a very high resistance of the produced materials to oil permeation (breakthrough time > 480 min). The mechanical properties, and especially tear resistance, of the studied materials were improved after the addition of modified bentonite (nanofiller) to the XNBR latex mixture. The nanocomposite meets the requirements in terms of parameters characterizing tear, abrasion, cut and puncture resistance. Therefore, the developed material may be used for the production of multifunctional protective gloves.