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The factors affecting the bound acrylonitrile content of NBR product during the polyme-rization process were investigated, including monomer reactivity ratio, monomer conversion, monomer concentration, and polymerization temperature and pressure, the structural composition of the product was analyzed, and the polymerization reaction kinetics and repeatability experiment were carried out. The results showed that under the polymerization temperature of 5.0 ℃ and polymerization pressure of 0.15-0.20 MPa, NBR products with uniform distribution of acrylonitrile structure units and mass fraction of bound acrylonitrile of 17%-19% could be obtained by using multi-stage addition of acrylonitrile and controlling the monomer conversion of 70%-75%. The polymerization formula and process had good repeatability.

A type of Al-MCM-41 supported dual imidazolium ionic liquids were constructed and efficiently used as catalysts for the synthesis of 2-oxazolidinones from epoxides, amines, and CO2. The influence of the different catalysts and reaction parameters on the catalytic behaviours was investigated. Al-MCM-41@ILTiCl5 was identified as the most excellent catalyst because it could efficiently promote the three-component cycloaddition of CO2, epoxide, and amines to form the corresponding 2-oxazolidinones in high to excellent yields (84∼96%) with excellent selectivities (98∼99.7%). In addition, the recovery and reuse performances of Al-MCM-41@ILTiCl5 were examined. The catalyst could be recovered by simple filtration and reused six times without a change in the catalytic activity. Green reaction conditions, operational simplicity, feasibility, and sustainability of the functionalized catalyst are the main highlights of the present protocol. [ABSTRACT FROM AUTHOR]

The efficient conversion of CO2 into value-added chemicals is of great importance. Herein, a type of transition metal-doped MCM-41 supported ionic liquids were synthesized, and efficiently used as catalysts for the effective carboxylative cyclization of propargylic alcohols and CO2 into α-alkylidene cyclic carbonates. The supported catalyst Cu-MCM-41@ILTiCl5 with a synergistic effect between the active copper sites and the anion could efficiently promote the carboxylative cyclization of propargylic alcohols and CO2 in high to excellent yields. After the reaction, the catalyst could be easily separated from the reaction mixture by simple centrifugation, and then reused for six times without noticeable decrease in the catalytic activity.These findings may be useful for the rational design of novel highly active and efficient catalysts for the transformation of CO2 into value-added α-alkylidene cyclic carbonates. An efficient protocol has been developed for producingα-alkylidene cyclic carbonates in excellent yields under cocatalyst- and solvent-free conditions by treating propargylic alcohols with carbon dioxide, promoted by Cu-MCM-41 supported ionic liquid catalyst. [ABSTRACT FROM AUTHOR]

In this work, a class of transition metal-modified MCM-41 mesoporous silica supported ionic liquids nanocatalysts were constructed and efficiently used as catalysts for the effective carboxylation of terminal alkynes through CO2 utilization. The main factors affecting the catalytic performance of carboxylation and its possible reaction mechanism were sufficiently discussed. The results showed that when the dosage was 0.2 g, the temperature was 40°C and the CO2 pressure was 0.3 MPa, the supported catalyst MCM-41@IL-Sm showed the optimal catalytic efficiency. The novel catalyst proved to be highly efficient for the sustainable synthesis of alkynyl carboxylic acids attributing good to excellent yields of 82%–95% within 7–12 h. Moreover, MCM-41@IL-Sm could be recycled and reused six times without noticeable decrease in catalytic activity from two-phase system under external heterogeneous field. The application of supported ionic liquids in the field of carbon dioxide carboxylation has injected a new power source for the efficient and effective production of value-added chemicals from waste CO2. [ABSTRACT FROM AUTHOR]

A type of MCM-41 supported dual imidazolium ionic liquids have been synthesized and efficiently used as catalysts in the sustainable chemical conversion of CO2 and epoxides into cyclic carbonates. It was shown that the highest efficiency was achieved in the cycloaddition of a variety of epoxides and CO2 in the presence of the MCM-41@DILSCN solid catalyst under mild conditions. More interestingly, the catalyst was stable, very active, robust, and displayed good recyclability without significant loss of catalytic activity after six consecutive cycles during the process. Overall, the present protocol of synthesizing cyclic carbonates under solvent free conditions using MCM-41@DILSCN is promising for industrial applications. [ABSTRACT FROM AUTHOR]

Efficient and sustainable chemical fixation of CO2 into value-added chemicals is one of the most promising objectives in environmental chemistry. In this work, transition metal acetylacetonate immobilized onto triazolium ionic liquid-modified periodic mesoporous organosilica PMO-IL-M(x) was successfully prepared and investigated as an effective and heterogeneous catalyst in the direct carboxylation of terminal alkynes and CO2 to the desired alkynyl carboxylic acids. It was found that the catalyst PMO-IL-Sn(0.3) exhibited extraordinary catalytic performance in terms of excellent activity, stability, productivity, and excellent yields under mild reaction conditions. Moreover, the catalyst PMO-IL-Sn(0.3) could be easily recovered and reused at least six times without considerable loss in catalytic activity. This work provides a sustainable and efficient synergistic strategy for the chemical fixation of carbon dioxide into valuable alkynyl carboxylic acids. [ABSTRACT FROM AUTHOR]

An efficient, experimentally simple, and convenient procedure for the C-O coupling of organic halides with phenols and alcohols in a [PEG.sub.1000]-DAIL[Cd[Cl.sub.3]]-toluene temperature-dependent biphasic system has been developed. The product can be easily isolated by a simple decantation, and the catalytic system can be recycled and reused without loss of catalytic activity. Key words: C-O coupling, organic halide, ionic liquid, thermoregulated ionic liquid biphasic system. On a mis au point une meethode commode, efficace et experimentalement simple de faire un couplage C-O d'halogenures organiques avec des phenols et des alcools dans un systeme biophysique [PEG.sub.1000]-DAIL[Cd[Cl.sub.3]]-toluene qui varie avec la temperature. Les produits peuvent etre facilement isoles par une simple decantation et le systeme catalytique peut etre recycle; et reutilise dans perte d'activite catalytique. Mots-cles : couplage C-O, halogenure organique, liquide ionique, systeme biphasique de liquide ionique soumis a une thermoregulation. [Traduit par la Redaction], Introduction The carbon-oxygen bond-forming reaction is one of the most fundamental transformations because of the large number of applications of the resulting compounds (ethers) in organic, pharmaceutical, and polymer chemistry. [...]