Silver® polystyrene sulfonate

Stationary Phase Use prepacked macroreticular polystyrene sulfonate divinylbenzene cation-exchange resin (2% to 8% cross-linked, 8- to 25-ptm particle size), preferably in the calcium or silver form. Examples of acceptable resins are Bio-Rad Aminex HPX-87C, or equivalent, for separating DPi-DP4 saccharides, and Aminex HPX-42C and HPX-42A, or equivalent, for separating DP1-DP7 saccharides. Maintain the column at 85° during operation. 

Both silver(I) and dimethylammonium polystyrene sulfonate polymers activated hydrogenations of nor-bornene and norbomadiene using this same catalyst. HCL absorption was a factor in these latter two activations. 

Insoluble polystyrene crosslinked with divinylbenzene can easily be converted by sulfonation to a usable ion exchanger. For this purpose a mixture of 0.2 g of silver sulfate and 150 ml of concentrated sulfuric acid are heated to 80-90 °C in a 500 ml threenecked flask fitted with stirrer, reflux condenser, and thermometer. 20 g of a bead polymer of styrene and divinylbenzene (see Example 3-41) are then introduced with stirring the temperature climbs spontaneously to 100-105 °C.The mixture is maintained at 100 C for 3 h,then cooled to room temperature and allowed to stand for some hours. Next the contents of the flask are poured into a 11 conical flask that contains about 500 ml of 50% sulfuric acid. After cooling, the mixture is diluted with distilled water, and the gold-brown colored beads are filtered off on a sintered glass filter and washed copiously with water. 

Based on experience, under the above conditions, production of at least 80-120 silver atoms per sulfonated center is adequate to provide a total metallic-type barrier to the passage of air. These extremely thin silver layers, when part of a vacuum-treated thermal insulation panel, conduct very little heat around the rims of the panel as is needed to achieve the desired high thermal insulation. For example, the thermal conductivities of an appropriately formed panel is typically as low as 0.007 watts m /m2oC as compared to values for polystyrene and polyurethane foams of 0.03-0.04 watts m /m2°C and 0.016-0.025 watts m /m2oC, respectively (3). ... 

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