Copal is the Spanish word used to describe aromatic resins from several genera of plants. Mexican copal derives from several Bursera spp., Protium copal, some Pinus spp. (e.g., P. pseudostrobus) and a few Fabaceae spp. It has been used for centuries as incense for religious ceremonies, as a food preservative, and as a treatment for several illnesses. The aim of this review is to analyze the che...

One approach to the study of wear involves the ch~~te~zation of surface failure under conditions of single-pass sliding. Such an approach has been used to show that the wear of commercial and experimental restorative resins and composites is determined by the resistance of the material to penetration and by the mode of deformation during sliding [l] . The purpose of this investigation was to ch...

Mijangos, F. and Diaz, M., 1990. Ion exchange recovery of metals from waste water of complex sulfide hydrometallurgy. Hydrometallurgy. 23: 365-375. The treatment by ion exchange ol' waste water from comples sulfide hydrometallurgy has Iwen studied. Several commercial resins have been tested for a range of pH in solution. The equilibrium results with an iminodiacetic resin for the multicomponent...

Vinyl acetate is a colorless, flammable liquid that also has a characteristic smell that can quickly become irritating. This monomer is used principally in the production of polyvinyl acetate (PVAc) and other vinyl acetate co-polymers. Polyvinyl acetate is a precursor of polyvinilyc alcohol and polyvinyl acetate resins (PVA). Vinyl acetate is also copolymerized as a minor raw material for vinyl...

The chromatographic method used to monitor the Bisphenol-A manufacturing process was improved using Agilent RRHT Eclipse XDB-C18 columns. These columns use 1.8-μm particles versus conventional 3.5-μm or 5-μm particles. The improved method allowed seven times faster analyses, improved resolution, and higher sensitivity. Introduction Bisphenol-A (Figure 1) is a highly versatile material used to m...

migration of compounds from packaging materials is one of the most important aspects of food safety. epoxy resins have been in inner coatings of food cans since the 1960s. these resins can be produced from bisphenol-a diglycidyl ether (badge) that is also utilized as a starter. migration of potentially toxic compounds in epoxy resins used for commercial cans is a very important food safety issu...

In this study, the development of lignin-based resins for wood adhesion applications was demonstrated. We investigated two lignin fractions: commercial Protobind 1000 and methanol-soluble fraction after mild solvolysis. Although has previously been incorporated into various cross-linked systems, is first report on thermosets obtained via thiol–yne “click” chemistry. approach, functionalized wit...

We report a method to enrich cysteinyl adducts of human serum albumin (HSA), representing biomarkers of exposure to systemic electrophiles. Because the major site of HSA adduction is the single free sulfhydryl group at Cys34, we used thiol-affinity resins to remove mercaptalbumin (i.e., unadducted HSA) from the cysteinyl adducts. Electrospray ionization mass spectrometry was used to detect merc...

With the classical sulfonation method of polystyrene-based strongly acidic cation exchange resins, polystyrene/polyvinylidene fluoride (PVDF) alloy particles were sulfonated to obtain a cation exchange resin, which was then directly thermoformed to prepare a semi-interpenetrating polymer network (semi-IPN) cation exchange membrane. The effects of the swelling agent, sulfonation time and tempera...

Scandium, a valuable element with restricted production sources mainly situated in China and Russia, is typically obtained as by-product during the of various materials. As demand for scandium grows expanding aluminum fuel cell industries, significant investments rare earth mining USA Australia, there need to explore alternative recovery sources. This research investigates from an acid pregnant...