Cationic Polymerization Of Styrene Research Articles

Cationic polymerization of styrene using iron-containing ionic liquid catalysts in an aqueous dispersed medium

This work aims to study the cationic miniemulsion polymerization of styrene catalyzed by iron-containing imidazolium-based ionic liquids. The polystyrenes had very high number-average molar mass around 1300 kg mol-1 at 85 °C, molar-mass dispersity close to 2.0 and glass transition temperature higher than 102 °C with average particle diameter that remained practically unchanged during the reaction, indicating that the monomer droplets correspond to the polymerization locus. First-order kinetics up to a limit conversion, along with the increase in molar mass as the temperature decreases, styrene polymerization at low temperatures and catalyst inability to polymerize monomers that react exclusively via free radical and/or anionic polymerization, indicate the cationic nature of polymerization. 1H-NMR and 13C-NMR spectra suggested the formation of polystyrene, allowing for tacticity distribution quantification: 10% isotactic, 20% atactic and 70% syndiotactic configurations. TEM micrographs confirmed the formation of spherical polymer nanoparticles and the presence of catalysts in the polymer matrix.

Acid-Activated Algerian Montmorillonite as Heterogeneous Catalysts for Cationic Polymerization of Styrene

Acid-Activated Algerian Montmorillonite as Heterogeneous Catalysts for Cationic Polymerization of Styrene

Cationic polymerization of styrene and indene initiated by aryl acetals in hexafluoroisopropanol medium

Benzaldehyde acetal and its para–susbstituted derivatives are capable of initiating the cationic polymerization of styrene and indene in hexafluoroisopropanol medium under essentially neutral conditions. As a result, polystyrenes carrying diverse functionalities at the α-terminus and having MWD characteristics comparable to those for the products of the conventional non-living cationic polymerization are produced.

Synthesis of long-chain branched isotactic-rich polystyrene via cationic polymerization

Cationic polymerization of styrene was conducted with 1-chloro-1-phenylethane (SCl)/AlCl3/phenyl methyl ether (PME) initiating system in hexane/CH2Cl2 (60/40, v/v) at −80 °C. The kinetics for cationic polymerization of styrene was investigated by in-situ ATR-FTIR spectroscopy. The isotactic-rich polystyrene (iPS) with m dyad of 81%, mm triad of 63% and mmmm pentad of 50% could be synthesized. Small amounts of crystalline regions in iPS formed after flow-induced crystallization and the crystallinity increased with increasing the molecular weight of iPS. Furthermore, the long-chain branched isotactic-rich polystyrene (biPS) with around 12 times higher molecular weight than that of corresponding iPS could be synthesized via cationic polymerization of styrene by introducing a small amount of isoprene (Ip) as a comonomer and branching sites as well. The possible mechanism for long-chain branching formation via intermolecular alkylation reaction by using Ip structural units along polymer chain as branching sites was proposed. The nucleation rate of biPS could be greatly enhanced with increasing the content of branching sites, leading to an obvious increase in crystallinity. The multi-melting temperatures from 140 °C to 237 °C were observed in DSC curves of these PS products. The tensile strength of commercial atactic polystyrene could be improved remarkably from 41.4 MPa to 55.7 MPa by adding 16.7% of biPS.

Reactivity of Heteropolymolybdates and Heteropolytungstates in the Cationic Polymerization of Styrene

The two heteropolyacids H3PW12O40 and H3PMo12O40, and their homologous salts (NH4)3PW12O40, and (NH4)3PMo12O40 were prepared and tested in the cationic polymerization of styrene. The results showed that the heteropolytungstates were more reactive than the heteropolymolybdates. It has been found that the yield and the viscosity average molecular weight (Mv) of polystyrene are directly proportional to the acidity strength of the heteropolyanions (H3PW12O40 > H3PMo12O40 > (NH4)3PW12O40 > (NH4)3PMo12O40). The highest yield (68.0%) and Mv (7,930) were obtained by using H3PW12O40. In addition, H3PW12O40 polymerized the styrene under mild conditions and was recyclable, and could behave as a truly heterogeneous catalyst.

Synthesis of nanotubes via cationic polymerization of styrene and divinylbenzene

A simple method for the preparation of nanoscale fibers and tubes by the cationic copolymerization of divinylbenzene (DVB) and styrene (ST) is described.

Cationic polymerization of styrene in scCO 2 and [bmim][PF 6

This work presents a study on the cationic polymerization of styrene in different reaction media, supercritical CO 2 (scCO 2), [bmim][PF 6], dichloromethane, and scCO 2 plus [bmim][PF 6] using AlCl 3 as initiator at temperatures from 273 to 333 K. The reactions were analyzed in relation to the monomer conversion rate, polymer structures, average molecular weights and molecular weight distribution. The polymerization reaction product was characterized by 1H and 13C nuclear magnetic resonance (NMR) and by gel permeation chromatography (GPC). In all cases, the styrene polymerization produced oligomers. Reactions using ionic liquid as a solvent led to higher molecular weight and monomer conversion rate. Monomer conversion rates of about 100% and weight average molecular weight ( M w) of 2400 at 298 K were obtained. Reactions with scCO 2 as a solvent yielded low monomer conversion rates (around 50%) and a M w = 2000 at 298 K. The oligolystyrenes presented rr syndiotatic-rich sequences in the microstructure in all reaction conditions. The use of ionic liquid and scCO 2 results in better yields than the use of the other organic solvents solvents.

Controlled/living cationic polymerization of styrene with BF 3OEt 2 as a coinitiator in the presence of water: Improvements and limitations

The controlled/living cationic polymerization of styrene using R–OH/BF 3OEt 2 (R–OH = 1-phenylethanol ( 1), 2-phenyl-2-propanol ( 2) and 1-(4-methoxyphenyl)ethanol ( 3)) at 0 °C in CH 2Cl 2 and in the presence of water was investigated. With 1/BF 3OEt 2, the poor control over molecular weight and molecular weight distribution was ascribed to a competitive protonic initiation induced by water. The molecular weight of the polymers obtained with 2/BF 3OEt 2 and 3/BF 3OEt 2 at low water content ([H 2O] ⩽ 0.11 M) increased in direct proportion to the monomer conversion in agreement with the calculated values, assuming that one initiator molecule generates one polymer chain, but the molecular weight distribution was found relatively broad ( M w/ M n ∼ 1.8). 1H NMR analyses confirmed that polymerization proceeds via reversible activation of C–OH terminus, but some loss of hydroxyl functionality was revealed. Some trials using high water contents in the recipe ([H 2O] ⩾ 1.6 M) produced only traces of polymer due to catalyst decomposition.

Cationic Polymerization of Styrene in Solution and Aqueous Suspension Using B(C6F5)3 as a Water-Tolerant Lewis Acid

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTCationic Polymerization of Styrene in Solution and Aqueous Suspension Using B(C6F5)3 as a Water-Tolerant Lewis AcidSergei V. Kostjuk and François GanachaudView Author Information Research Institute for Physical Chemical Problems of the Belarusian State University, Leningradskaya St., 14, 220050 Minsk, Belarus, and Laboratoire de Chimie Macromoléculaire, UMR 5076 CNRS/ENSCM, 8 Rue de l'Ecole Normale, 34296 Montpellier Cedex, France Cite this: Macromolecules 2006, 39, 9, 3110–3113Publication Date (Web):April 8, 2006Publication History Received12 December 2005Revised21 March 2006Published online8 April 2006Published inissue 1 May 2006https://doi.org/10.1021/ma052650zCopyright © 2006 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1289Altmetric-Citations58LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (141 KB) Get e-AlertsSUBJECTS:Cationic polymerization,Monomers,Polymerization,Styrenes,Suspensions Get e-Alerts

Chemistry of Styrene (Water)nClusters,n= 1−5: Spectroscopy and Structure of the Neutral Clusters, Deprotonation of Styrene Dimer Cation, and Implication to the Inhibition of Cationic Polymerization

The styrene-water binary clusters SW(n), with n = 1-5 have been studied by the (one-color) resonant two-photon ionization technique using the resonance of styrene. The structures and energetics of the neutral clusters are investigated using a search technique that employs Monte Carlo procedure. The strong tendency for water molecules to form cyclic hydrogen-bonded structures is clearly observed in the SW(n) structures starting from n =3. The results indicate that the spectral shifts correlate with the interaction energies between styrene and the water subcluster (W(n)) within the SW(n) clusters. Evidence is presented that points to (1) the formation of a covalent bonded styrene radical cation dimer following the 193 nm MPI of styrene neutral clusters, (2) proton transfer from the styrene dimer cation to the water or methanol subcluster, resulting in the formation of protonated water or methanol clusters and a styrene dimer radical, and (3) extensive solvation of the styrene dimer radical within the protonated solvent molecules. The proton-transfer reactions may explain the strong inhibition effects exerted by small concentrations of water or methanol on the cationic polymerization of styrene. These results provide a molecular level view of the inhibition mechanism exerted by protic solvents on the cationic polymerization of styrene.

Development and characterization of a microfiltration membrane catalyst containing sulfonated polystyrene grafts

Polymeric catalytic membrane reactors (CMRs) containing sulfonated polystyrene grafts can serve as an alternative to traditional strong acid catalysts such as sulfuric acid and strong acid ion-exchange resins (IERs) for esterification and alkylation reactions. This material offers advantages over conventional catalysts in terms of corrosivity, attrition, pressure drop, mass transfer limitations, and catalyst separation. The membrane reactors are functionalized membranes created by cationic polymerization of styrene in the pores of a porous matrix of polyethersulfone (PES). Sulfonation of the formed polystyrene grafts with sulfuric acid creates easily accessible sulfonic acid groups (∼2 meq/g) for catalysis. Diffusional limitations encountered in ion-exchange resins are minimized because transport through the membrane pore takes place by convection. Consequently, the membrane activation is accomplished with lower concentration acid. The activated membrane shows no loss of functionalized polymer during activation, demonstrating excellent material stability. Finally, the catalytic activity was verified for a simple esterification reaction between acetic acid and ethanol.

Cationic polymerization of styrene in a neutral ionic liquid

AbstractThe cationic polymerization of styrene in a neutral ionic liquid, 1‐butyl‐3‐methylimidazolium hexafluorophosphate, with a 1‐phenetyl chloride/TiCl4 initiating system is reported. The polymerization proceeds to a high conversion, but an analysis of the matrix‐assisted laser desorption/ionization time‐of‐flight spectra of the polymers indicates that chain transfer is significant, leading to a lack of control over the molecular weight and molecular weight distribution. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3230–3235, 2004

Cationic polymerization of styrene on the surface of graphite expanded

AbstractCationic polymerization of styrene initiated by the CO+ClO group on the surface of expanded graphite (EG) was carried out for modifying the surface properties of graphite. The initiating sites were achieved by the reaction of EG with SOCl2 and followed by AgClO4. Subsequently, the cationic polymerization of styrene was conducted to afford polystyrene brush on EG. The influence factors, such as polymerization time and temperature, on the polymerization including the grafting ratio and efficiency were investigated. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2715–2721, 2003

Resonant Two-Photon Ionization Spectroscopy of Styrene (Methanol)nClusters,n= 1−9

Well-resolved spectra of styrene−methanol binary clusters SMn, with n = 1−9, have been obtained by the (one-color) resonant two-photon ionization technique using the resonance of styrene. The spectra reveal a rapid increase in complexity with the number of methanol molecules in the cluster, associated with van der Waals modes and isomeric forms. Two distinct isomers are identified for each of the clusters studied with the exception of SM4 and SM8. The progressive addition of methanol molecules to the SM complex leads to the formation of stable cyclic and branched cyclic methanol subclusters within the SMn clusters. The spectral shift of the cluster origin reflects the nature of the intermolecular interactions within the binary cluster. Blue shifts are observed for the SM, SM2, and SM3 clusters and are consistent with hydrogen bonding interactions between the OH groups and the styrene π-system. A remarkable switch in the spectral shift from blue to red is observed at the SM4 cluster and is consistent with the ring structure of the methanol tetramer. Evidence is provided for intracluster dissociative proton-transfer reactions within the S2Mn+ (n > 2) clusters that generate protonated methanol clusters. These reactions may explain the strong inhibition effects exerted by small concentrations of methanol on the cationic polymerization of styrene.

Spectroscopy and structure of styrene (water) n and styrene (methanol) n clusters, n=1,2

Resonant two-photon ionization (R2PI) spectra of styrene–water (SW n ) and styrene–methanol (SM n ) binary clusters with n=1,2 are reported. The results indicate that the SW n clusters exhibit different structures as compared to the benzene (water) n clusters. Ab initio calculations of the lowest energy structure of the SW complex confirm that water interacts mostly with the ethylene group. Two distinct isomers are identified for the SM 2 cluster. The favorable interactions of water and methanol with the olefin group of styrene may explain the strong inhibition effects observed by trace concentrations of water or methanol on the cationic polymerization of styrene.

Cationic polymerization of styrene in the presence of added base: Living nature of the propagating species and synthesis of poly(vinyl alcohol)-graft-polystyrene

Cationic polymerization of styrene in the presence of added base: Living nature of the propagating species and synthesis of poly(vinyl alcohol)-graft-polystyrene

Synthesis of Poly(styrene−dimethylsiloxane) Block Copolymers: Influence of the Phase-Separated Morphologies on the Thermal Behaviors

Five polystyrene−poly(dimethylsiloxane) di- and triblock copolymers were prepared by two different methods, a classical anionic polymerization and a cationic polymerization of styrene in the presence of a new macromolecular initiator. Spherical, cylindrical, and lamellar phase-separated morphologies were identified. Their sizes were measured by transmission electron microscopy (TEM) on films obtained from bulk and solvent-cast samples. DSC and TEM show that the phase-separated morphologies are strongly segregated with no long range ordering. The specific microphase surface area, obtained by TEM, is strongly correlated with the broadening of the polystyrene glass transition.

Surface grafting of polymers onto glass plate: Polymerization of vinyl monomers initiated by initiating groups introduced onto the surface

The surface grafting of polymers onto a glass plate surface was achieved by the polymerization of vinyl monomers initiated by initiating groups introduced onto the surface. Azo groups were introduced onto the glass plate surface by the reaction of 4,4′-azobis(4-cyanopentanoic acid) with isocyanate groups, which were introduced by the treatment with tolylene-2,4-diisocyanate. The radical polymerization of various vinyl monomers was initiated by azo groups introduced onto the glass plate surface and the corresponding polymers were grafted from the surface: The surface grafting of polymers was confirmed by IR spectra, and the contact angle of surface, with water. The contact angle of the glass plate increased by the grafting of hydrophobic polymers, but decreased by the grafting of hydrophilic polymers. The radical postpolymerization was successfully initiated by the pendant peroxycarbonate groups of grafted polymer on the surface to give branched polymer-grafted glass plate. The cationic polymerization of vinyl monomers was also successfully initiated by benzylium perchlorate groups introduced onto the glass plate surface and the corresponding polymers were grafted onto the surface. The contact angle of the glass plate surface obtained from the cationic polymerization of styrene was larger than that obtained from the radical polymerization. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2165–2172, 1997

Synthesis of Poly(Styrene)-block-poly(methacrylate)-block-poly(styrene) via Site Transformation Reaction

Triblock copolymers with polystyrene outer blocks and an inner polymethacrylate block were synthesized by a site transformation reaction using anionic and cationic polymerization techniques. In order to obtain such ABA block copolymers, two synthetic routes have been applied. In the first case, different methacrylates (methyl methacrylate, 2-ethylhexyl methacrylate) were polymerized anionically with a bifunctional initiator to get poly(methacrylate) dianions later forming the inner block whereas in the second case poly(styrene)-block-poly(methacrylate) anions were synthesized by monofunctional initiation via sequential monomer addition. In a subsequent step, the living chain ends of the methacrylate dianions on one side, and the diblock copolymer anions on the other side, were functionalized with 1,4-bis(l-bromoethyl)benzene in order to obtain a potential bifunctional or monofunctional macroinitiator for the cationic polymerization of styrene. Then, styrene was polymerized cationically with the macroinitiator in the presence of SnCl4 as coinitiator and n Bu4NBr as a common ion salt in CH2Cl2 at -15°C. Block formation was proven by SEC measurements, preparative SEC and NMR characterization.

Cationic polymerization of styrene and indene in iodine/liquid sulfur dioxide system

The cationic polymerizations of indene (Ind) and styrene (Sty) initiated by iodine (I2) in liquid sulfur dioxide (SO2) were investigated. Reactions involving Ind were characterized by termination by neutralization between the growing carbocationic species and the nucleophilic counteranion, at low temperature. Sty polymerization is also termination-dominated and gives low conversion at -20°C. High resolution gas chromatography coupled with mass spectrometry (HGC-MS) analysis of non polymeric material in the Sty polymerization suggested that initiation of Sty polymerization involves the formation of 1,2 diiodide adduct prior to initiation with HI.