Solvent-impregnated resins impregnation

Laminates. Laminate manufacture involves the impregnation of a web with a Hquid phenoHc resin in a dip-coating operation. Solvent type, resin concentration, and viscosity determine the degree of fiber penetration. The treated web is dried in an oven and the resin cures, sometimes to the B-stage (semicured). Final resin content is between 30 and 70%. The dry sheet is cut and stacked, ready for lamination. In the curing step, multilayers of laminate are stacked or laid up in a press and cured at 150—175°C for several hours. The resins are generally low molecular weight resoles, which have been neutralized with the salt removed. Common carrier solvents for the varnish include acetone, alcohol, and toluene. Alkylated phenols such as cresols improve flexibiUty and moisture resistance in the fused products. 

Extraction with solvent impregnated resins. A. Warshawsky, Ion Exch. Solvent Extr., 1981, 8, 229-310(102). 

The development of solvent-impregnated resins and extraction-chromatographic procedures has enabled the automation of radiochemical separations for analytical radionuclide determinations. These separations provide preconcentration from simple matrices like groundwater and separation from complex matrixes such as dissolved sediments, dissolved spent fuel, or nuclear-waste materials. Most of the published work has been carried out using fluidic systems to couple column-based separations to on-line detection, but robotic methods also appear to be very promising. Many approaches to fluidic automation have been used, from individual FI and SI systems to commercial FI sample-introduction systems for atomic spectroscopies. 

A simpler approach for depositing water insoluble chemicals within the cell walls of wood is to impregnate the wood with solvent soluble resin forming chemicals containing a catalyst that penetrate the cell walls followed by evaporation of the solvent and then heating to polymerize the resin. This has been accomplished with the following water soluble resin forming systems phenol, resorcinol, melamine and urea-formaldehydes, phenol -furfural, furfuryl-aniline and furfuryl alcohol (44). 

EXTRACTION WITH SOLVENT-IMPREGNATED RESINS Abraham Warshawsky... 

Ana Maria Sastre is a professor of chemical engineering at the Universitat Politecnica de Catalunya (Barcelona, Spain), where she has been teaching chemistry for more than 28 years. She received her PhD from the Autonomous University of Barcelona in 1982 and has been working for many years in the field of solvent extraction, solvent impregnated resins, and membrane technology. 

Our studies on solvent-impregnated resins, consisting of soluble compounds of type IB impregnated onto macroporous polymer carriers, have enabled us to conclude that a hydrophilic or amphiphilic component must be present in the polymeric network, in order to allow for fast ion diffusion inside the polymeric matrix. It is imperative that this component possesses none or minimal metal-ligand properties, so that it will not interfere with the ion selectivity of the main chelating group [6,7]. 

A. Warshawsky, Solvent impregnated resins, in J.zX. Marinsky and Y. Marcus (Eds.), Ion Exchange and Solvent Extraction, Vol. X, Marcel Dekker. New York, 19X1. Chap.. 3. 

A. Waishewsky. Entiaction with Solvent-Impregnated Resins, in 1. A. Marinsky and Y. Marcus... 

Developments in Solid-Liquid Extraction by Solvent-Impregnated Resins... 

The use of impregnated resins or solvent-impregnated resins in extraction and recovery processes dates back to the pioneering work developed in the earlier 1970s by Warshawsky [1], Grinstead [2], and Kroebel and Meyer [3 and the topic has been thoroughly dealt with in some papers and reviews. Since the last review in 1981 [4] a whole series of important advances have been made. The present review has been written with the following objectives in mind ... 

As viewed by the present review, the most distinctive feature of solvent-impregnated resins as solid sorbents is their macroporous structure, which differentiates them from all other types and/or sorts of solid sorbents used in separation chemistry which are compact (granular) or foams (polyurethane). 

In a previous review [4] the preparation methods for producing efficient solvent-impregnated resins (SIRs) were classified as ... 

Many attempts have been made to investigate the interactions occurring at solid-liquid interfaces due to their technological, hydrometallurgical, and/ or analytical implications. Although the fixation of metal cations on solvent-impregnated resins has been extensively investigated, little has been done to characterize the physicochemical interactions between the solvent and the solid support. 

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