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SynopsisThe crosslinking or curing reaction of polystyrylpyridine (PSP) has been studied by means of thermal reactions of its model compounds. Compounds 2,6-distyrylpyridine, 4-stilbazole (4-styrylpyridine), and deuterated 4-stilbazole were pyrolyzed a t 200-325OC both in air and under vacuum in a sealed tube. The major pyrolysis products were diarylethane and stilbene, and were characterized by gas chromatography-mass spectrometry. Major dimeric products were naphthalene or quinoline derivatives. Mechanisms for the pyrolysis are suggested, and a crosslinked structure for cured PSP is proposed based on the thermal reaction products of model compounds.

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The usual procedure for the determination of americium and curium in a variety of samples consists of a series of decontamination steps in the presence of La3+ ion, followed by the separation of Am and Cm from La (1)(2)(3). This final separation is usually done by coprecipitation of Am and Cm with La(OH)3, washing the precipitate, redissolution in a few drops of 13N HC1, and a chromatographic separation in a micro cation exchange column. Such a column requires careful calibration and operation for several hours.A few years ago, Schumacher and Friedli (4-6) reported the use of ion focusing electrophoresis for the separation of the rare earths from one another and proposed a separation scheme for the rare earths and for mixtures of rare earths and actinides. Consequently, a study was initiated in this laboratory to find a rapid and simple application of ion focusing electrophoresis for the separation of Am and Cm from La. EXPERIMENTALApparatus. The electrophoresis chamber (Figure I) was constructed entirely of borosilicate glass. The semi-cylindrical chamber with an overall length of 22 cm and a width of 4.5 cm consisted of two electrode compartments, 3 cm in length, and a center compartment, 16 cm in length. The center compartment was filled with CC14 to provide a sink for the heat generated by the electric current passing through the electrolyte-saturated paper strip. The paper strip was held in place by two slotted pieces of Teflon located at each end of the cooling compartment. Platinum electrodes were clipped to the ends of the paper strip in the electrode compartments which are filled with the appropriate electrolytes. Current was supplied by a Shasta Model 702A constant power supply, capable of delivering up to 600 volts and a maximum current recommended not to exceed 200 ma.Materials. All chemicals used were reagent or CP grade. The paper used was Whatman No. 3 MM filterpaper strip, 1.3 cm wide and cut into 25-cm lengths.For autoradiography, Polaroid Land type 57 film was used. An acetate base sheet with 2-3 mg ZnS/cm2 3456backing, trade name ALPH-A-CAL, a Division of the Grayden Co., Williston, S. C., was used to enhance the registration of alpha particles on the film.Procedure. The anode solution consisted of 0.2N HC104. The cathode solution had the following composition, as recommended by Schumacher (5): 0.15M (NH4>2 H(NTA) (NTA: nitrilotriacetic acid); 0.20M CH3 COONH4; 0.164/ CH2 ClCONH4; pH = 5.0.The sample of no more than 0.5 mg of La with "'Ce as a tracer and containing the actinides to be separated, was