Sulfonated hyper-cross-linked polymers based on 4,4′-bis­(chloromethyl)-1,1′-biphenyl (BCMBP) were synthesized via metal-free (SHCP-1) and conventional Lewis acid-catalyzed (SHCP-2) Friedel–Crafts alkylation routes. The sulfonated polymers possessed BET surface areas in excess of 500 m2·g–1. SHCP-1 was investigated for its ability to extract Sr and Cs ions from aqueous solutions via the ion-exchange reaction of the sulfonic acid moiety. Equilibrium uptake data could be accurately modeled by the Dubinin–Radushkevich isotherm, with maximum calculated loading values of 95.6 ± 2.8 mg·g–1 (Sr) and 273 ± 37 mg·g–1 (Cs). Uptake of both target ions was rapid, with pseudo second-order rate constants calculated as 7.71 ± 1.1 (×10–2) for Sr and 0.113 ± 0.014 for Cs. Furthermore, the polymer was found to be highly selective toward the target ions over large excesses of naturally occurring competing metal ions Na, K, Mg, and Ca. We conclude that hyper-cross-linked polymers may offer intrinsic advantages over other adsorbents for the remediation of aqueous Sr and Cs contamination.

The measured viscosity for concentrated solutions of linear coiling polymers decreases with increasing rate of shear. By use of a theory previously derived to explain this phenomena, it is possible to determine the absolute molecular weight of the polymer from measurements of this effect. The necessary data required for this determination are readily obtained using a simple cone viscometer. Since the theory requires only a knowledge of the variation of viscosity with shear rate together with the polymer concentration and temperature to compute the molecular weight, the method is easily applied to any polymer of this general type. This shear rate method for determining molecular weights has been checked by measuring M for a large number of samples of polystyrene and polymethyl methacrylate. Satisfactory results are obtained on these polymers. When the method is used as outlined, it gives a value for M which is close to the viscosity average. For very wide molecular weight distributions, the value found is somewhat higher than the weight average. Since the method is only strictly valid for linear polymers, it appears that it may also be used in conjunction with other molecular weight methods to obtain useful information concerning the extent of branching in the molecules.

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It has been shown that the shear-rate dependence of the viscosity of concentrated polymer solutions can be explained in terms of known parameters of the solution. If the concentration, temperature, zero shear viscosity, and molecular weight of the polymer are known, the decrease in viscosity with increasing shear rate can be predicted. Conversely, if one measures the shear-rate dependence of the viscosity, the molecular weight may be computed. We believe this provides a convenient method for the absolute determination of molecular weights of linear, coiling, high polymers.