The Influence of Pore-Forming Diluents on Porous Structure, Thermal and Sorption Properties of the Divinylbenzene and Glycidyl Methacrylate Copolymers

The aim of this work was the characterization of polymer microspheres obtained by the suspension polymerization of divinylbenzene (DVB) and glycidyl methacrylate (GMA), depending on the pore-forming diluents and molar ratio of monomers. The assessed properties included the chemical and porous structure, thermal stability, and sorption capacity of the obtained polymers towards methylene blue. The abovementioned characteristic was carried out for two series of copolymers with molar ratios of monomers of 1:2, 1:1 and 2:1, synthetized with toluene and a mixture of decanol and benzyl alcohol. The structure of the polymers was confirmed by FTIR and elemental analysis. The results of TGA demonstrated the main influence on thermal stability was the composition of polymers, whereas the impact of porogens was negligible. The SBET varied in the range of 12-534 m2g-1 for polymers obtained with toluene and 0-396 m2g-1 with the mixture of alcohols. Toluene enhanced the formation of micro- and mesopores, while the mixture of alcohols enhanced the creation of meso- and macropores. For the polymers prepared with toluene, their effectiveness in water purification decreases in the following order: DVB-GMA 2:1 > DVB-GMA 1:1 > DVB-GMA 1:2, according to the decreasing values of porous structure parameters. In the case of a series obtained with a mixture of alcohols, such correlation was not observed.

Use of a cross-linked polystyrene/titanium tetrachloride tightly bound coordination complex as catalyst for the production of petroleum resins

Immobilized titanium tetrachloride containing was demonstrated to be an effective and water-tolerant solid acid cationic initiator for the cationic polymerization of an industrial liquid pyrolysis gasoline feedstock.

Tris-imidazolinium-based porous poly(ionic liquid)s as an efficient catalyst for decarboxylation of cyclic carbonate to epoxide

A series of imidazolinium-based porous poly(ionic liquid)s (PILs) with different anions prepared by free-radical copolymerization of an arene-bridged tris-vinylimidazolium salt and divinylbenzene (DVB) were constructed. The as-prepared PILs were characterized by BET, SEM, TEM, TGA and Elemental Analysis (EA), and the results showed that they had plentiful ionic sites, and abundant and stable mesopores. In particular, the density of ionic sites and pore structure of PILs could be controlled by adjusting the content of DVB. Moreover, the PILs were used as efficient heterogeneous catalysts for the decarboxylation of cyclic carbonates to epoxides for the first time. Results showed that the catalytic activity of PILs was positively correlated with the nucleophilicity of the anions in PILs, and PDVB-[PhTVIM]Cl-1 with a chloride anion-enriched skeleton displayed the best catalytic performance. Without any solvent or cocatalyst, PDVB-[PhTVIM]Cl-1 achieved a TOF value of 108.1 h-1 and the yield of butylene oxide of 89.6%, which was even better than the homogeneous IL-based catalysts (TOF value: 8.7 h-1) that had been previously reported. Meanwhile, PDVB-[PhTVIM]Cl-1 also exhibited excellent recyclability and substrate compatibility.

Phenylglyoxaldehyde-Functionalized Polymeric Sorbents for Urea Removal from Aqueous Solutions

For realization of a wearable artificial kidney based on regeneration of a small volume of dialysate, efficient urea removal from dialysate is a major challenge. Here a potentially suitable polymeric sorbent based on phenylglyoxaldehyde (PGA), able to covalently bind urea under physiological conditions, is described. Sorbent beads containing PGA groups were obtained by suspension polymerization of either styrene or vinylphenylethan-1-one (VPE), followed by modification of the aromatic groups of poly(styrene) and poly(VPE) into PGA. It was found that PGA-functionalized sorbent beads had maximum urea binding capacities of 1.4-2.2 mmol/g and removed ∼0.6 mmol urea/g in 8 h at 37 °C under static conditions from urea-enriched phosphate-buffered saline, conditions representative of dialysate regeneration. This means that the daily urea production of a dialysis patient can be removed with a few hundred grams of this sorbent which, is an important step forward in the development of a wearable artificial kidney.

Functional Interfaces Constructed by Controlled/Living Radical Polymerization for Analytical Chemistry

The high-value applications of functional polymers in analytical science generally require well-defined interfaces, including precisely synthesized molecular architectures and compositions. Controlled/living radical polymerization (CRP) has been developed as a versatile and powerful tool for the preparation of polymers with narrow molecular weight distributions and predetermined molecular weights. Among the CRP system, atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) are well-used to develop new materials for analytical science, such as surface-modified core-shell particles, monoliths, MIP micro- or nanospheres, fluorescent nanoparticles, and multifunctional materials. In this review, we summarize the emerging functional interfaces constructed by RAFT and ATRP for applications in analytical science. Various polymers with precisely controlled architectures including homopolymers, block copolymers, molecular imprinted copolymers, and grafted copolymers were synthesized by CRP methods for molecular separation, retention, or sensing. We expect that the CRP methods will become the most popular technique for preparing functional polymers that can be broadly applied in analytical chemistry.

One-pot synthesis of highly folded microparticles by suspension polymerization

A facile method of preparing highly folded cross-linked polymeric microparticles has been developed via one-pot suspension polymerization under high-speed homogenization. The wrinkles result from the evaporation of solvent in the cross-linked microparticles. The effects of microparticle cross-linking density and solvent on the polymer have been studied in detail. It was found that a medium cross-linking density (DVB/St = 0.5 by weight) is optimal for producing the most folded surface and the higher the solvent content, the deeper the surface wrinkles. This method is very simple and in principle can be applied to produce wrinkled microparticles with other chemical compositions.