Обсуждаются изотермы сорбции/десорбции азота при 77 К и паров бензола при 293 К на различных сверхсшитых полистирольных смолах. Форма изотерм N 2 для всех образцов идентична и характеризуется крутым подъемом адсорбционной ветви при низком относительном давлении р / р 0 , а также последующим менее крутым наклоном ветви при увеличении относительного давления. Изотерма адсорбции бензола имеет слабовыраженный выпуклый начальный участок со значительным увеличением емкости сорбента при повышении относительного давления. Высказано предположение, что подъем изотермы в обоих случаях отражает релаксацию внутреннего напряжения с одновременным увеличением объема сетки. Различие между двумя типами изотерм обусловлено тем фактом, что в сетке, охлажденной до 77 К, напряжение больше и начальный объем образца сильнее сжат. Адсорбция азота и бензола при относительном давлении 0.95, – это величины одного порядка, что указывает на сходную степень набухания сверхсшитого полистирола в обоих сорбатах. Адсорбционное поведение сверхсшитых полимеров типа PIM (Рolymers of Intrinsic Microporosity) управляется теми же эффектами.

This contribution is focused on the examination of adsorption/desorptiom isotherms for nitrogen at 77 K and benzene vapors at 293 K on various hypercrosslinked polystyrene (HP) resins. All isotherms for N 2 are identical in their shapes and are characterized by a steep rise of the adsorption branch at low p / p 0 followed by a less steep hoisting of the branch with increasing relative pressure. Adsorption isotherm for benzene demonstrates an ill-defined convex initial part followed by a significant rise in network loading with further increase in relative pressure. In the both cases we assume the rise in adsorption to reflect the relaxation of inner stresses with the simultaneous increase in the volume of networks. The distinction between the two types of isotherms is conditioned upon the fact that in the networks cooled down to 77 K stresses are stronger and the initial volume of the sample is more compressed. The amounts of nitrogen and benzene absorbed at relative pressure of 0.95 are the same order of magnitude, indicating similar swelling of HP in the both adsorbates. The adsorption behaviors of hypercrosslinked PIM-type polymers are governed by the same effects.

The study is focused on the development of a "one-pot " procedure for preparing hypercrosslinked polystyrene sorbents. The method is based on in situ formation of monochlorodimethyl ether (MCDE) via the reaction of methylal with chloroanhydrides of organic and inorganic acids, while ensuring that chloroanhydride is used in quantities sufficient for both the obtaining of MCDE and complete scavenging of methanol at the moment of its formation during the subsequent reaction of the ether with polystyrene. CH3COCl, (COCl)(2), SO2Cl2 and POCl3 exemplify the chloroanhydrides. FeCl3 served as the catalyst. All above chloroanhydrides are consumed exhaustively; they do not act as crosslinking agents and do not introduce any functional groups. Specific inner surface area, methanol and water uptake and adsorption of organic substances from aqueous solutions onto obtained hypercrosslinked polystyrenes do not differ from those characteristic of sorbents prepared by a direct crosslinking polystyrene with MCDE.

This contribution was focused on the developing of an improved method for preparing hypercrosslinked polystyrene by bridging styrene-0.5% DVB copolymer with monochlorodimethyl ether (MCDE) up to 100, 150, 200 and 300% via Fidel–Crafts reaction. The modification comprises both the reduction in the consumption of the catalyst, SnCl4, and the complete substitution of SnCl4 with the more active and less expensive catalyst, FeCl3. Reducing the SnCl4 quantity from 1.0 to 0.1 mol per one mole of the ether leads to the formation of hypercrosslinked networks which exhibit a quite good swelling in non-solvents, rater low apparent density, and a noticeable pore volume, but, surprisingly, to a dramatic reduction in the measured inner surface area. The latter finding could be explained by the formation in the networks with very narrow pores which remain inaccessible to the testing argon atoms. The situation changes cardinally if the reaction mixture is additionally provided with oxalyl chloride (0.5 mol per mol of the ether) which reacts with methanol at the moment of its formation during the reaction of the ether with polystyrene. The latter reaction proceeds so violently that it is possible to reduce the amount of SnCl4 by a factor of at least 13 or diminish the essential portion of FeCl3 by a factor of 30, compared to the recommended previously 0.3 mol FeCl3 per one mole of the MCDE.

Polycondensation of rigid-chain di- and triacetylarenes and their copolycondensation has afforded three-dimensional polymers via the formation of 1,3,5-phentriyl and dipnone moieties. The influence of the monomers structure on the polymers properties has been analyzed. Additional thermal treatment at 450оC has afforded microporous polyphenylenes with phentriyl branching fragments exhibiting intrinsic surface area of 650–690 m2/g.

Gel type polymers, polymers of expanded structure and macroporous polymers of styrene mostly with 6 mole% of divinylbenzene have been obtained by suspension polymerization, expanded and macroporous structures being prepared in the presence of 1.5 volumes of toluene or iso-octane, respectively. All three types of copolymers were further converted into highly porous hypercrosslinked products by their intensive post-crosslinking with monochlorodimethyl ether. For all samples obtained, the inner specific surface area, total pore volume, apparent density, and uptake of toluene, methanol and water have been measured. It was found that the swelling of macroporous and hypercrosslinked porous polymers results in an increase in the volume of the polymeric phase and decrease in the volume of large pores with insignificant rise in the total size of the polymeric beads. Swelling of porous polymers thus mainly proceeds at the expense of space of internal voids.

С целью упрощения и удешевления синтеза сверхсшитых сорбентов вновь изучена реакция сшивания набухшего в дихлорэтане сополимера стирола с 0.7% ДВБ монохлордиметиловым эфиром по реакции Фриделя-Крафтса. Пористые полимеры с удельной поверхностью 800-1000 м2/г можно получить, используя 1 моль дорогих безводных SnCl4 и TiCl4 на моль эфира. Безводные AlCl3 и FeCl3вызывают деструкцию исходного сополимера, а ZnCl2 оказался неактивным. Однако раствор смеси 70г ZnCl2 и 3.5 г FeCl3 в 50 мл концентрированной соляной кислоты является перспективным катализа-тором. Выполняя одновременно роль многоразового катализатора и дисперсионной среды, он позво-лил впервые получить пористые гранулы даже из линейного полистирола, проводить сшивание поли-мера без его деструкции и заменить эфир нетоксичным метилалем.

It was shown that self-condensation of p-xylylene dichloride (p-XDC) and its co-polycondensation with naphthalene, anthracene, benzyl alcohol, and benzhydrol in presence of the Lewis acids in solution leads to the formation of hypercrosslinked polymers characterized by developed porosity and ability to swell in nonpolar and polar media. Swelling and porosity of the polycondensed network do not depend on dilution of the initial monomer mixture or catalyst amount involved in the reaction as opposed to the properties of hypercrosslinked polymer. The similarities and differences of the regularities of formation of structures obtained at intense crosslinking of linear polymers (polystyrene) and polycondensed networks were examined. It was also estimated that copolymers with naphthalene and anthracene demonstrate perfect ability to extract furfural (which is able to participate in strong π–π interactions) even from methanol solution.

Разработаны особые условия суспензионной сополимеризации стирола с дивинилбензолом, позволяющие уменьшить размер гранул до 30-60 мкм и существенно сузить распределение гранул по диаметру. Полученный в этих условиях сополимер с 0.7% дивинилбензола был сшит монохлордиметиловым эфиром до степени сшивания 100 и 200%. Сорбенты в статических условиях извлекают 83-95% фенилкарбоновых кислот из водного разбавленного подкисленного раствора. Десорбция кислот щелочным метанолом близка к 100%. Сорбенты не поглощают альбумин. Принадлежность сорбентов к классу материалов ограниченного доступа продемонстрирована также на примере полного разделения методом ВЭЖХ смеси плазмы, лекарства Амперозид, его метаболита и родственных соединений, при этом белки плазмы не удерживались и выходили с мертвым объемом.

Polyphenylene gels are obtained for the first time by trimerization polycondensation of a number of diacetylaromatic compounds, and their structure is studied by IR spectroscopy and argon thermal desorption.

Тримеризационной полициклоконденсацией ряда диацетилароматических соединений впервые получены полифениленовые гели. Строение синтезированных полимеров изучено ИК-спектроскопией и методом тепловой десорбции аргона.

With a view to simplifying and reducing the cost of the synthesis of novel selective restricted-access materials based on microporous hypercrosslinked polystyrene for solid-phase extraction, various polystyrene crosslinking agents and Friedel–Crafts catalysts in various combinations have been studied. It has been found that the most effective crosslinking agent is monochlorodimethyl ether; in addition, expensive tin chloride has been effectively replaced with a smaller amount of cheap ferric chloride. Under special conditions for the suspension copolymerization of styrene with 1, 2, and 3% of divinylbenzene, copolymers with a bead size of 30–70 μm have been synthesized. Each of the copolymers has been further crosslinked with monochlorodimethyl ether to a degree of crosslinking of 100, 150, and 200%. These polymers are porous materials swellable in water and any organic solvents. The hypercrosslinked polymer network is not accessible to large molecules of proteins (Cytochrome C and albumin) and does not cause protein adsorption; owing to this feature, the sorbents can be classified as novel selective restricted-access materials.

A number of hypercrosslinked polystyrene networks are studied. The networks are obtained via additional crosslinking of granules of styrene copolymer with 0.5% divinylbenzene (0.3–0.5 mm) and microgranules with 1% divinylbenzene (3.5 µm) using monochlorodimethyl ether to densities of crosslinking from 60 to 500%. It is found that as the degree of crosslinking grows, the absorption in the electronic spectrum of the polymer extends to the visible region, and the granules change color (toward as dark as black); this phenomenon is much less expressed for microgranules and milled materials. For a consistent explanation of these two observations, assumptions are made about the appearance and increase in the contrast of density fluctuations of a tracery hypercrosslinked network and light scattering on such micro-inhomogeneities in the volume of particles of the compared series of polymers.

The reversible sorption preconcentration of noble metals (NMs) prior to their determination by inductively coupled plasma–mass spectrometry (ICP-MS) was investigated. Six new hypercrosslinked polystyrene sorbents were tested. The dependence of the degree of NMs sorption on the average degree of polymer network crosslinking and pore diameters was investigated. It was found that sorbents HP-100/6, HP-300/6 and HP-500/6 have low efficiency of NMs chlorocomplexes extraction. Among Stirosorb sorbents (Stirosorb-2, Stirosorb-514 and Stirosorb-584) the highest efficiency of the extraction of NMs’ chlorocomplexes has Stirosorb-514. Tributylamine (TBA), N-methylbenzylamine (MBA), N,N-dimethylbenzylamine (DMBA), N,N-dibenzylmetylamine (DBMA) were studied as the reagents for extraction of Ru, Rh, Pd, Ir, Pt and Au chlorocomplexes from hydrochloric acid solutions in the form of ion associates by reversed-phase mechanism. The reversible quantitative extraction of Ru, Pd, Pt and Au in system Stirosorb-514 – TBA – 1M HCl in ethanol as eluent was achieved. It was found that resulting eluates do not contain matrix components which may cause spectral interferences on the stage of NMs determination by ICP-MS. The found scheme of NMs reversible sorption was validated by the analysis of certified reference materials of basic and ultrabasic rocks GPt-5, GPt-6 and SARM-7. Good agreement between the measured NMs concentrations and the certified values was demonstrated. The achieved limits of detection for Ru, Pd, Pt and Au vary within 10−8–10−7wt% range.