Ion-exclusion chromatography (IEC) has been widely used in the separation of carboxylic acids, finding applications in the analysis of food and beverages, pharmaceuticals, biological samples, and acid rain samples.1 The retention mechanism of carboxylic acids in ion-exclusion chromatography has also been investigated in many studies, and the factors which affect retention can be divided into th...

Background. In vitro studies have revealed a direct association between resin content and cytotoxicity of composite resins; however, implantation studies in this regard are sparse. This study investigates the relationship between filler content of composite resins and biocompatibility. Methods. This research employed twelve 180‒200-gr male Wistar rats, 1 nano-hybrid (Prime-Dent Inc.) and 1 micr...

STATEMENT OF PROBLEM Computer-aided design and computer-aided manufacturing (CAD/CAM) resins exhibit good mechanical properties and can be used as long-term restorations. The wear rate of such resins and their enamel antagonists is unknown. PURPOSE The purpose of this study was to test and compare the 2-body wear rate of CAD/CAM resin blocks. MATERIAL AND METHODS Wear specimens (N=42, n=6) ...

With the phasing out of lead-bearing solders, electrically conductive adhesives (ECAs) have been identified as an environmentally friendly alternative to tin/lead (Sn/Pb) solders in electronics packaging applications. Compared to Sn/Pb solders, conductive adhesive technology offers numerous advantages. However, this new technology still has reliability limitations. Two critical limitations are ...

Effect of glazing with an ultraviolet light-activated coating material on reduction of the leaching of methyl methacrylate and formaldehyde from denture acrylic resins was quantitatively evaluated. Disks prepared from auto-polymerized resins were painted with the material and radiated with ultraviolet light. The disks were immersed in artificial saliva and the concentrations of methyl methacryl...

In this work two types of lignin-novolac resins have been formulated, partially substituting phenol by softwood ammonium lignosulfonate as filler or extender (methylolated) to study the viability of that substitution when resins will be employed as adhesives in textile felts. A commercial novolac resin was used as reference. Free phenol, free formaldehyde, water content, softening point, and fl...

A previous study of synthesizing low mole ratio urea–formaldehyde (UF) and urea–melamine–formaldehyde (UMF) resins, which included an acidic reaction step at the beginning of the typical resin synthesis procedure to obtain higher uron-type methylene–ether group contents, was repeated with the acidic reaction step extended to a higher viscosity. Compared to previous resins, the synthesized resin...

The use of chlorotrityl resins for the immobilization of amines is sometimes deterred by the lengthy process of loading the reactants on the resins and product decomposition caused by the reactive chlorotrityl group in the presence of 1% TFA as a cleavage agent. Here, we report improved methods developed for selective and efficient loading of aminobenzoic acid derivatives on chlorotrityl resins...

Unsaturated polyester and epoxy vinyl ester resins have broad utility in composite applications. Today’s commercially available premium thermal performance vinyl ester resins are derived from novolac epoxies and methacrylic acid. These products combine low viscosity with shelf stable, yet fast curing properties, and enable fabricators to manufacture composite parts with rapid throughput for dem...