Various derivatives (ethoxycarbonylmethyl, carboxymethyl, and ethoxyethyl, etc.) of calix [4] arene, calix [6]arener and calix [8]arene have been synthesized and their ion-binding properties investigated by solvent extraction, ion-transport through liquid membranes, and U.V. spectroscopy. The extraction of various metal ions (as picrate salts) from the aqueous phase into dichloromethane by the calixarene derivatives showed that the ethoxycarbonylmethyl derivatives exhibited markedly increased extraction efficiency compared with their unsubstituted phenol analogues, and the efficiency was in general comparable to those of crown ethers. The most notable feature was the selectivities exhibited by their ethoxycarbonylmethyl derivatives; calix[4]arene for Na+, calix[6]arene for Cs+, and calix[8]arene for K + . A liquid membrane study with a water-chloroform-water system also indicated that the iontransport efficiencies exhibited by calixarenes were found to be in accordance with their extraction abilities, confirming the strong participation of the ester carbonyl oxygen in this function. However, the ester derivative of calix [4]arene was an exception in that inefficient carrier activity was observed in spite of high extraction efficiency. The pronounced Cs+ selectivity exhibited by the calix[6]arene ester was further confirmed by the changes in the U.V. spectrum of the ester from 277 and 270 nm to 275 and 267 nm upon interaction with Cs+ ion in methanol.

SynopsisPoly(methy1 methacrylatebpolystyrene composite particle latexes were prepared by poly(methy1 methacrylatehseeded emulsion polymerization of styrene employing batch, swelling-batch, and semibatch methods. The changes in particle morphology taking place during the polymerization reaction were followed by electron microscopy. Anchoring effect exerted by ionic terminal groups introduced by ionic initiator was found to be the main factor in controlling the particle morphology. The polymer particles obtained by oil-soluble hydrophobic initiators such as azobisisobutyronitrile and 4,4'-azobis44-cyanovaleric acid) gave the inverted core-shell morphology. Water-soluble hydrophilic initiator, K2&08, also gave the inverted coreshell morphology. However, in this case the occurrence of the halfmoonlike, the sandwichlike, and the core-shell morphologies were also observed depending upon the polymerization conditions. The distribution of terminal S O T groups on the surface area of polystyrene particles could be controlled by initiator concentration and polymerization temperature. Viscosity of polymerization loci dictated the movement of polymer molecules, thus causing the unevenness of particle shape and phase separation at high viscosity state. Viscosity was controlled by the styrene/poly(methyl methacrylate) ratio, the addition of a chain transfer agent or a solvent which is common to polystyrene and poly(methy1 methacrylate).

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Glycolide (GL) and ⑀-caprolactone (CL) were copolymerized in bulk at relatively high temperatures using stannous octoate as a catalyst. To investigate the relationship among microstructure, thermal properties, and crystallinity, three series of copolymers prepared at various reaction temperatures, times, and comonomer feed ratios were prepared and characterized by 1 H and 13 C NMR, DSC, and wide-angle X-ray diffraction (WAXD). The 600-MHz 1 H NMR spectra provided information about not only the copolymer compositions but also about the chain microstructure. The reactivity ratios (r G and r C ) were calculated from the monomer sequences and were 6.84 and 0.13, respectively. In terms of overall feed compositions, the sequence lengths of the glycolyl units calculated from the reactivity ratios exceeded those measured from the polymeric products. Mechanistic considerations based on reactivity ratios, monomer consumption data, and average sequence lengths are discussed. The unusual phase diagram of GL/CL copolymers implies that the copolymer melting temperature does not depend on its composition alone but rather on the nature of the sequence distribution. The DSC and WAXD measurements show a close relationship between polymer crystallinity and the nature of the polymer sequence.

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