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...

Chelating resins have been considered to be suitable materials for the recovery of heavy metals in water treatments. A chelating resin based on modified poly(styrene-alt-maleic anhydride) with Melamine was synthesized. This modified resin was further reacted with 1,2-diaminoethan in the presence of ultrasonic irradiation for the preparation of a tridimensional chelating resin on the nanoscale f...

This study examined the average surface roughness (Ra, microm) of 2 microfilled (Durafill and Perfection), 1 hybrid (Filtek Z250) and 2 packable composite resins (Surefil and Fill Magic), before (baseline) and after eight different finishing and polishing treatments. The surface roughness was assessed using a profilometer. Ten specimens of each composite resin were randomly subjected to one of ...

Wood liquefaction was conducted at a 2/1 phenol/wood ratio in two different reactors: (1) an atmospheric three-necked flask reactor and (2) a sealed Parr reactor. The liquefied wood mixture (liquefied wood, unreacted phenol, and wood residue) was further condensed with formaldehyde under acidic conditions to synthesize two novolac-type liquefied wood/phenol/formaldehyde (LWPF) resins: LWPF1 (th...

The removal of copper from aqueous solution by Amberjet 1500H, Amberjet 1300H and Amberlite IRC86 ion exchange resins is described. The Amberjet 1500H shows a remarkable increase in sorption capacity for copper compared to other adsorbents. The adsorption process shows maximum removal of copper in pure aqueous solution for an initial copper concentration of 5.98 mmol/L. The metal ions adsorptio...

Ion exchange resins have been used to help formulate pharmaceuticals since the late 1950's. During that time they have proved to be safe and effective excipients and are now used in many commercial formulations throughout the world. In this article we will look at some of the common problems faced by formulators and how using ion exchange resins may be able to solve them. Ion exchange resins ar...