ABSTRACT The direct oxidative carboxylation of olefins and CO 2 is a green and effective route to synthesize cyclic carbonates. Therefore, developing catalysts capable of efficient catalytic activity under relatively mild conditions is of great importance. In this work, two structurally identical two‐dimensional metal‐organic frameworks, nickel‐catecholate (Ni‐CAT) and cobalt‐catecholate (Co‐CAT), were synthesized at ambient temperature using water as solvent, thereby avoiding the energy consumption associated with high‐temperature synthesis and the environmental pollution caused by organic solvents. Both catalysts exhibited excellent catalytic performance. Through the combination of catalytic activity evaluation, kinetic studies, and structural characterizations, it was demonstrated that Lewis acidic amounts had a beneficial effect on the CO 2 cycloaddition step but a detrimental influence on the olefin epoxidation reaction. Using Ni‐CAT as the catalyst under mild conditions (80°C, 0.1 MPa CO 2 , 10 h, solvent‐free), styrene (ST) conversion and ST carbonate yield reached 99% and 90%, respectively. Furthermore, after five reaction cycles, the catalytic activity of Ni‐CAT and Co‐CAT showed no significant decline. Finally, based on these characterization and experimental results, mechanisms for this catalytic reaction were proposed.

A facile approach is reported on the large-scale synthesis of robust polymeric discs by seeded swelling emulsion polymerization against a PS hollow sphere, which is exemplified by using the monomer mixture of vinyl benzene chloride (VBC) and divinyl benzene (DVB). The interplay between strong phase separation of the in situ synthesized polymer and confined Ostwald ripening within the shell is responsible for the formation of the discs. Selective modification of the crosslinked PVBC (cPVBC) disc is allowed while one side is protected with the polystyrene (PS) shell. The benzyl chloride group at cPVBC enables easy preferential growth of desired functional materials by many strategies. The example Janus disc of PNIPAM-cPVBC-PEO is achieved after grafting poly(ethylene oxide)-amine (PEO-NH2) via nucleophilic substitution and poly(N-isopropylacrylamide) (PNIPAM) via Atom Transfer Radical Polymerization (ATRP) at the corresponding sides. The disc is amphiphilic from the Lower Critical Solution Temperature (LCST) of PNIPAM to the cloud point of PEO, which becomes hydrophilic at lower temperature and hydrophobic at higher temperature.

Poly­(styrene-alt-maleic anhydride) (SMAnh),analternating copolymer composed of electron-rich styrene (STY) andelectron-deficient maleic anhydride (MAnh) comonomers, was synthesizedvia reversible addition–fragmentation chain transfer (RAFT)-mediatedpolymerization, using either a trithiocarbonate, dithiobenzoate, ordithiocarbamate chain transfer agent (CTA). SMAnh copolymers withdifferent terminal repeat units (MAnh vs STY) were subjected to eitherradical-induced reduction or thermolysis to facilitate the transformationof the thiocarbonylthio functional chain end. The chemical compositionof the ω-chain end and the solvency conditions employed duringeach end-group removal process were found to significantly influencethe rate and extent of removal/transformation of the thiocarbonylthiofunctional group. MAnh-functional ω-chain ends enhanced thelability of the thiocarbonylthio group for all end-group removal strategiesassessed, suggesting that electron-deficient chain ends facilitatehigher efficiency removal of thiocarbonylthio functional groups. Additionally,3,5-dimethyl pyrazole dithiocarbamate chain ends were reduced or thermolyzedfaster and to a higher degree than trithiocarbonate- or dithiobenzoate-functionalchain ends.

The selective separation of hydrocarbons such as styrene (ST) and ethylbenzene (EB) remains a formidable challenge in the petrochemical industry due to their nearly identical molecular structures and physicochemical properties. Herein, we report a robust, water-soluble, metal-free tetracationic cyclophane (B) capable of achieving>99% selective extraction of ST from EB in aqueous media with excellent recyclability. B features a hydrophobic, conformationally adaptive cavity (∼6.5Å×14.3Å) that selectively recognizes planar over nonplanar guests in aqueous medium. Solution-state and solid-state analyses confirm that the preferential binding of ST is driven by favorable interactions with its vinyl group and induced planarization of the host. B also distinguishes phenanthrene (P) from 9,10-dihydroanthracene (DHA), further validating its precision in shape-selective molecular recognition. Our findings demonstrate a unique aqueous separation of ST from EB employing a metal-free receptor that advances the design of selective host-guest systems and supports greener alternatives for hydrocarbon purification.

Abstract The selective separation of hydrocarbons such as styrene (ST) and ethylbenzene (EB) remains a formidable challenge in the petrochemical industry due to their nearly identical molecular structures and physicochemical properties. Herein, we report a robust, water‐soluble, metal‐free tetracationic cyclophane (B) capable of achieving >99% selective extraction of ST from EB in aqueous media with excellent recyclability. B features a hydrophobic, conformationally adaptive cavity (∼6.5 Å × 14.3 Å) that selectively recognizes planar over nonplanar guests in aqueous medium. Solution‐state and solid‐state analyses confirm that the preferential binding of ST is driven by favorable interactions with its vinyl group and induced planarization of the host. B also distinguishes phenanthrene (P) from 9,10‐dihydroanthracene (DHA), further validating its precision in shape‐selective molecular recognition. Our findings demonstrate a unique aqueous separation of ST from EB employing a metal‐free receptor that advances the design of selective host–guest systems and supports greener alternatives for hydrocarbon purification.

Atomic‐level confinement of PtCu nanoclusters within MFI‐type zeolite enables unprecedented kinetics in alkyne semi‐hydrogenation

Abstract The production of styrene (ST) by the petrochemical industry has traditionally relied on the ethylbenzenedehydrogenation (EB) reaction, using iron‐based catalysts. Estimates suggest that in 2025, the production of EB and ST will surpass 36 and 41 million tons, respectively. In this manner, the major aspects that led to the present stage of EB and ST production were described, discussing historical aspects, alternatives to produce these solvents, its characteristics, types of oxidants, and properties of iron‐based catalysts. Noteworthy advancements in this field include the utilization of CO2 as a soft oxidant and the employment of innovative catalysts derived from green synthesis methods. On the other hand, as an alternative to the fossil source for EB production, the utilization of lignin from biomass emerges as a promising eco‐friendly approach. The potential for implementing the ODH reaction in alternative reactors gives rise to questions regarding the necessity for industry to adapt to current climate needs. Furthermore, certain aspects of the mechanism have been called into question, as some fundamental points remain to be fully consolidated. These include the extent of the participation of CO2 in the reactivation of the active sites and the origin of the deposited coke.

Abstract Acrylonitrile‐butadiene‐styrene (ABS) is a widely used amorphous terpolymer with remarkable high‐impact resistance. However, its high insulation characteristics due to the non‐polar structure limit its further applications. This paper introduces the blending of specific antistatic agents, polyamide type antistatic agent (ABS‐2MP), and polyether type antistatic agent (JL‐AS‐55) with ABS. The influence of the presence of the antistatic agent, monomer ratio of styrene (ST) and acrylonitrile in ABS resin, and the rubber content is demonstrated, and finally a high‐impact resistant ABS resin with excellent antistatic properties is obtained. As a result, the hydrophilicity and corresponding antistatic properties of ABS resin were improved by using a higher proportion of ST monomers. With 20% antistatic agent and 24 phr rubber, the resin showed the best antistatic effect. The addition of polyamide 6 further improved the tensile strength and antistatic properties of the resulting material. This research serves to improve and balance the mechanical properties and antistatic properties of ABS resins, overcome the inherent defects, and provide a comprehensive method to broaden the application scope of ABS, which has a vital role in various industrial applications.Highlights High‐impact ABS resin with excellent antistatic properties was prepared. The effect of resin composition on the antistatic properties was studied. The synergistic effects of different antistatic agents were evaluated.

CO2 adsorption in humid conditions has wide industrial uses, but the low uptake of adsorbents and the inferior efficiency of amines present a notable challenge for its development. Through the copolymerization of acrylamide (AAm), styrene (ST), and N-(3-(dimethylamino)propyl)methacrylamide (DMAPMA), we developed a thermoresponsive adsorbent with tunable amine sites. In a humid environment, the tertiary amines of the DMAPMA moiety keep an extended state and are exposed to the CO2 molecules at 20 °C. The optimal adsorption capacity is 3.78 mmol g–1 with 1 mol of amine reacting with 0.98 mol of CO2. This amine efficiency in adsorption surpasses that of various typical adsorbents. At 80 °C, the adsorption capacity decreases to 1.10 mmol g–1, with only 0.34 of the amine efficiency. The elevated temperature makes the AAm moiety form intramolecular H-bonds with the DMAPMA moiety; thus, the amines are shielded in the adsorbent’s particles. This change of amines couples with the feature of adsorption swing, making adsorbents have both the satisfied adsorption capacity and the convenience of desorption.

Photochemical processes are often thought to be temperature-independent.However, photochemical polymerization involves photochemical processessuch as light-driven radical generation coupled with thermal-drivenreactions such as monomer propagation. The apparent activation energyof propagation, EA(Rp), of a series of three monomers, methyl acrylate (MA), methylmethacrylate (MMA), and styrene (STY), are deduced from Arrheniusanalysis of conventional and RAFT photopolymerization of these monomersacross a range of corresponding temperatures. The deduced EA(Rp) was comparedwith the benchmarked EA(kp) derived from pulse laser polymerizations coupled withsize exclusion chromatography (PLP-SEC). For conventional photopolymerizationof MA, MMA and STY, the relatively small discrepancy between the photopolymerization-derived EA(Rp) and the EA(kp) from PLP-SECwas rationalized due to temperature-induced changes in termination.The deviation between the EA(Rp) measured in RAFT photopolymerization and EA(kp) from PLP-SEC dependson the retardation strength in RAFT polymerizations. MMA and STY monomersare characterized with minimal retardation and recorded excellentagreement in PLP-SEC and RAFT-derived Ep values. However, the RAFT photopolymerization of MA, which is subjectto strong retardation, had a much larger EA(Rp) than the EA(kp) from PLP-SEC. The high apparent EA(Rp) in RAFT polymerizationof MA is likely due to the added influence of temperature-inducedchanges in the RAFT equilibrium. Overall, these results rationalizetemperature-dependent effects in photochemical reactions.

The chain-length-dependent nature of the termination reaction in radical polymerization (RP) renders the overall termination rate coefficient, <kt>, a complex parameter in the usual situation where the radical chain-length distribution is non-uniform. This applies also for the activation energy of termination, Ea(<kt>), which we subject to detailed mechanistic investigation for the first time. The experimental side of this work measures Ea(<kt>) for the dilute-solution, low-conversion, chemically initiated homopolymerization of styrene (ST), methyl methacrylate (MMA), butyl methacrylate, and dodecyl methacrylate. Values of 25-39 kJ mol-1 are obtained, consistent with strong chain-length-dependent termination (CLDT) for short chains. On other hand, the reanalysis of analogous bulk polymerization data for ST and MMA finds Ea(<kt>) values of 18-24 kJ mol-1, consistent with weak CLDT for long chains. Both these results are as expected from the so-called composite model for CLDT. A simple analytic framework for understanding and predicting Ea(<kt>) values is presented for the standard RP situation of continuous initiation. All the results of this work can be rationalized via this framework, which clearly establishes that Ea(<kt>) is determined by far more than just the Ea of radical diffusion. This framework is extended to activation energy for the number-average degree of polymerization, Ea(DPn), which we measure and successfully scrutinize via our CLDT model. In the final section of this work, we make interesting, testable predictions about Ea(<kt>) and/or Ea(DPn) in various RP systems of different natures to those studied here, most notably, systems involving acrylates, continuous photoinitiation, or dominant chain transfer.

The influence of myrcene on anionic copolymerization of 1,3-pentadiene and styrene

Abstract In this study, two cardanol based epoxidized resins, NC514 with less than two epoxies per molecule and side chain epoxidized cardanol glycidyl ether (SCECGE) with approximately 2.45 epoxies (1.0 phenolic+1.45 aliphatic epoxies) per molecule were methacrylated. The methacrylated versions of cardanol based NC514 (NC514VE) and SCECGE (SCECGEVE) epoxy resins were used as cross‐linker units in vinyl ester formulations with methacrylated lauric acid (MFA) and styrene (ST) as bio‐based and synthetic based reactive diluents respectively, at various concentrations (10–40 wt%). The curing reactions of the resins were studied via FTIR and the extent of polymerization was determined for different cross‐linker units in the presence of ST and MFA. Our mechanical and thermomechanical characterizations showed that VER formulations prepared with cardanol based SCECGEVE cross‐linker unit have significantly improved properties than the samples prepared with commercially available counterpart NC514VE using either reactive diluent. These properties of SCECGEVE were also comparable with to that of methacrylated petroleum‐based diglycidyl ether of bisphenol A vinyl ester (DGEBAVE) formulations unlike NC514VE formulations due to more effective side chain functionalization and cross‐linking.

When encountering heavy oil reservoirs during drilling, due to the change in pressure difference inside the well, heavy oil will invade the drilling fluid, and drilling fluid will spill into the reservoir along the formation fractures, affecting the drilling process. A supramolecular polymer gel-based temporary plugging agent was prepared using acrylamide (AM), butyl acrylate (BA), and styrene (ST) as reacting monomers, N, N-methylenebisacrylamide (MBA) as a crosslinking agent, ammonium persulfate (APS) as an initiator, and poly(vinyl alcohol) (PVA) as a non-covalent component. A supermolecular polymer gel with a temperature tolerance of 120 °C and acid solubility of 90% was developed. The experimental results demonstrated that a mechanically robust, thermally stable supramolecular polymer gel was successfully synthesized through the copolymerization of AM, BA, and ST, as well as the in situ formation hydrogen bonding between poly (AM-co-BA-co-ST) and PVA, leading to a three-dimensional entangled structure. The gel-forming solution possessed excellent gelling performance even in the presence of a high content of salt and heavy oil, demonstrating superior resistance to salt and heavy oil under harsh reservoir conditions. High-temperature and high-pressure plugging displacement experiments proved that the supramolecular polymer gel exhibited high pressure-bearing capacity, and the blocking strength reached 5.96 MPa in a wedge-shaped fracture with a length of 30 cm. Furthermore, the dissolution rate of the supramolecular polymer gel was as high as 96.2% at 120 °C for 48 h under a 15% HCl solution condition.

Simple and efficient sample pretreatment methods are important for analysis and detection of chemical warfare agents (CWAs) in environmental and biological samples. Despite many commercial materials or reagents that have been already applied in sample preparation, such as SPE columns, few materials with specificity have been utilized for purification or enrichment. In this study, ionic magnetic mesoporous nanomaterials such as poly(4-VB)@M-MSNs (magnetic mesoporous silicon nanoparticles modified by 4-vinyl benzene sulfonic acid) and Co2+@M-MSNs (magnetic mesoporous silicon nanoparticles modified by cobalt ions) with high absorptivity for ethanol amines (EAs, nitrogen mustard degradation products) and cyanide were successfully synthesized. The special nanomaterials were obtained by modification of magnetic mesoporous particles prepared based on co-precipitation using -SO3H and Co2+. The materials were fully characterized in terms of their composition and structure. The results indicated that poly(4-VB)@M-MSNs or Co2+@M-MSNs had an unambiguous core-shell structure with a BET of 341.7 m2·g-1 and a saturation magnetization intensity of 60.66 emu·g-1 which indicated the good thermal stability. Poly(4-VB)@M-MSNs showed selective adsorption for EAs while the Co2+@M-MSNs were for cyanide, respectively. The adsorption capacity quickly reached the adsorption equilibrium within the 90 s. The saturated adsorption amounts were MDEA = 35.83 mg·g-1, EDEA = 35.00 mg·g-1, TEA = 17.90 mg·g-1 and CN-= 31.48 mg·g-1, respectively. Meanwhile, the adsorption capacities could be maintained at 50-70% after three adsorption-desorption cycles. The adsorption isotherms were confirmed as the Langmuir equation and the Freundlich equation, respectively, and the adsorption mechanism was determined by DFT calculation. The adsorbents were applied for enrichment of targets in actual samples, which showed great potential for the verification of chemical weapons and the destruction of toxic chemicals.

Unravelling a complex catalyst deactivation in which selectivity affects conversion: oxygen-assisted styrene synthesis at industrially-relevant conditions

The adsorption of oligomeric peroxide of sebacic acid on aerosols was studied. The parameters of the adsorption process were found. The effect of aerosil on the polymerization of styrene (ST), methyl acrylate (MA), butyl acrylate (BA), methyl methacrylate (MMA) and butyl methacrylate (BMA) was studied. The initiators used were oligomeric sebacic acid peroxide (OPSA), benzoyl peroxide (BP), lauryl peroxide (PL) and didecanoyl diperoxy adipinate (DP). The mineral filler increases the polymerization rate of MMA, BMA, MA, BA initiated by OPSA. Under the same conditions, the polymerization rate of ST decreases with an increase in the aerosil content in the polymerization system. BP practically does not affect the polymerization rate of vinyl monomers in the presence of aerosil. The reaction of thermal decomposition of OPSA, DP, PL and BP in styrene in the presence of aerosol was studied. An increase in the content of aerosil leads to an increase in the effective decomposition constant of OPSA, DP, PL. in the case of BP, aerosil has practically no effect on the decomposition rate.

Fluorinated polymers are important materials in everyday life; however, most monomers of widely used fluoropolymers are gaseous, and their polymerization is difficult in an ordinary laboratory. Therefore, partially fluorinated polymers have recently been reported. As an easy-to-handle fluorine-containing monomer, α-trifluoromethylstyrene (TFMST) can be used to produce partially fluorinated polymers with trifluoromethyl groups in the main chain; however, TFMST does not homopolymerize, and there are limited reports on its copolymerization with styrene (ST). In this study, we applied the controlled radical polymerization method, which is effective for the polymerization of ST, to the copolymerization of TFMST and ST. We also showed that nitroxide-mediated polymerization is effective. The content ratio of TFMST in the TFMST–ST copolymer can be controlled between 10% and 40% by changing its monomer ratio. Additionally, the polymerization of TFMST and ST with substituents was performed to increase structural variations. The thermal stability as well as water and oil repellency of the synthesized polymers with different composition ratios and substituents were also evaluated.

Promotional effect and mechanism of SiO2 on Cr-Al2O3 catalysts for N2O-assisted oxidative dehydrogenation of ethylbenzene

Indium nanocubes based recyclable fluorescent chemosensor for sustainable environmental monitoring: pH-induced fluorescence transition and selective detection of Pd(II) ions