Hydrogen‐Assisted Unique Incorporation of 1,4‐Divinylbenzene in Copolymerization with Propylene Using an Isospecific Zirconocene Catalyst

Summary: Propylene was copolymerized with 1,4‐divinylbenzene (1,4‐DVB) using rac‐Me₂Si(2‐Me‐4‐Ph‐Ind)₂ZrCl₂ and MAO in the presence of hydrogen. ¹H NMR spectra of the obtained copolymer confirmed the successful incorporation of 1,4‐DVB. ¹³C NMR analysis revealed a unique copolymer structure with the incorporated 1,4‐DVB units predominantly forming 1,4‐substituted phenyl repeating units in the polymer main chain. A plausible mechanism involving spontaneous insertion of terminal styryl into Zr‐H species was proposed to rationalize the unique incorporation of 1,4‐DVB.

Copolymerization of propylene with 1,4‐divinylbenzene in the presence of hydrogen.     

Chiral polyamino alcohols and polyamino thiols for asymmetric heterogeneous catalysis

A series of macroporous copolymer beads were synthesized by THE free radical suspension copolymerization of (S)-glycidylmethacrylate (GMA), (S)-thiiranylmethylmethacrylate (TMA), or (R,R)-phenylglycidylmethacrylate (Ph-GMA) with ethyleneglycol dimethacrylate (EDMA) or divinylbenzene (DVB). This allowed for the evaluation of their chemical and physical properties (polymer matrix nature or the structure of the heterocyclopropane) and their influence on the catalytic efficiency. These chiral polymers were subsequently transformed into polyamino alcohol or polyamino thiol derivatives by the facile ring opening of the oxirane or thiirane group with benzylamine and methylamine. Complexed with [RuCl₂(p-cymene)]₂, these derivatives were shown to be effective in the asymmetric hydrogen transfer reduction of acetophenone. The best results (conversion: 94%, ee: 71%) were obtained with benzylamine grafted onto poly(GMA-co-EDMA) (30/70 % wt/wt).     

Synthesis of core‐shell poly(divinylbenzene) microspheres via reversible addition fragmentation chain transfer graft polymerization of styrene

Styrene has been grafted from crosslinked poly(divinylbenzene) core microspheres by both reversible addition fragmentation chain transfer (RAFT) polymerization and conventional free radical polymerization. The core microspheres were prepared by precipitation polymerization. Crosslinked poly(DVB) core microspheres containing double bonds on the particle surface can be used directly to graft polymers from the surface by RAFT without prior modification of the core microspheres. The RAFT agent 1‐phenylethyl dithiobenzoate (PEDB) was used: Particle sizes increased from 2 μm up to 3.06 μm, and the particle weight increased by up to 6.5%. PEDB controls the particle weight gain, the particle volume, and the molecular weight of the soluble polymer. PEDB was also used to synthesize core poly(DVB) RAFT microspheres that contain residual RAFT end groups on the surface and within the particle. Styrene was subsequently grafted from the surface of these core poly(DVB) RAFT microspheres. The generated microspheres were characterized by ¹H‐NMR spectroscopy, focused ion beam (FIB) milling, Coulter particle sizing, and size exclusion chromatography. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5067–5076, 2004     

Synthesis of functionalized linear poly(divinylbenzene). II. Synthesis of poly(divinylbenzene) with hydroxyl pendants and/or endgroups

Poly(divinylbenzene) [poly(DVB)] derivatives having hydroxyl terminals and/or pendants were synthesized by chemical modifications (hydration and hydroxylation) of unsaturated linear poly(DVB) ( I ), which was prepared by the polymerization of DVB catalyzed by acetyl perchlorate. Hydroboration of both terminal and in-chain carbon–carbon double bonds in I with BH₃.THF complex yielded a fully hydrated poly(DVB) II , in which hydrophilic and hydrophobic groups are placed alternately. Selective hydroboration of the vinyl endgroups in I with 9-borabicyclo[3.3.1]nonane led to an α,ω-dihydroxy-poly(DVB) ( III ). Reaction of I with m-chloroperbenzoic acid gave fully epoxidated poly(DVB) IV , which was subsequently hydrated to yield polymer V consisting of glycol repeat units and terminals. The physical properties and reactions (chain extension and crosslinking) of these polymers were also studied.     

Syntheses and reactions of functional polymers. XCIII. Syntheses of polymers containing the N-(4-hydroxy-3-nitrophenyl)succinimide structure in the chain and the use of these activated polymer esters of N-blocked amino acids or peptides

Polymers containing the N-(4-hydroxy-3-nitrophenyl)succinimide residue were designed in order to achieve acyl activation of a reacting carboxylic acid in the solid phase. These polymers were prepared through the following three routes: (a) styrene was allowed to copolymerize with N-(4-hydroxy-3-nitrophenyl)- or N-(4-acetoxy-3-nitrophenyl)maleimide, (b) styrene was copolymerized with N-(4-acetoxyphenyl)maleimide in the presence of divinylbenzene (DVB), and the copolymer obtained was hydrolyzed and nitrated, (c) a copolymer of maleic anhydride and styrene was reacted with p-aminophenol, followed by nitration. The polymers prepared by routes b and c were converted to the activated polymer esters of N-blocked amino acids and peptides by using dicyclohexylcarbodiimide (DCC). The acylated polymers thus obtained were treated with amino acid esters and found to give peptides quantitatively without racemization.     

Synthesis of norbornene/divinylbenzene copolymers catalyzed by anilinonaphthoquinone-ligated nickel complexes and their applications for the synthesis of graft polymers

The copolymerization of norbornene (NB) and divinylbenzene (DVB) was carried out using anilinonaphthoquinone-ligated nickel complexes of the type [Ni(C₁₀H₅O₂NAr)(Ph)(PPh₃)] ( 1a : Ar = C₆H₃-2,6- ⁱPr; 1b : Ar = C₆H₂-2,4,6-Me; 1c: Ar = C₆H₅) with modified methylaluminoxane (MMAO) as a cocatalyst. The DVB content was varied (5–25 mol%) and the resulting copolymers exhibited number-average molecular weights (M_n) of 40,000–69,000 g/mol with polydispersities (PDI = 1.5–1.8). The styryl group of the NB/DVB copolymer was used for grafting poly(methyl methacrylate) by reverse atom transfer radical polymerization using azobisisobutyronitrile in the presence of copper chloride and bipyridine.     

A first example of macromolecular Ti(IV) Lewis acid in the catalytic enantioselective Mukaiyama reaction

The preparation and characterization of a soluble copolymer P1 between styrene, divinylbenzene (DVB) and the enantiomerically pure salicylaldimine ligand 3c is described. The Lewis acid prepared from this macromolecular chiral ligand and Ti(OⁱPr)₄ has been used in the catalytic Mukaiyama reaction to afford benzyl (R)-3-hydroxy-3-phenylpropanoate 7.     

Star‐branched polystyrenes by nitroxide living free‐radical polymerization

Star‐branched polystyrenes, with polydispersity indices of 1.15–1.56 and 4–644 equal arms, were synthesized by the reaction of 2,2,6,6‐tetramethylpiperidin‐1‐yloxy (TEMPO)‐capped polystyrene (PS‐T) with divinylbenzene (DVB). The characterization of PS‐T and the final star polymers was carried out by size exclusion chromatography, low‐angle laser light scattering, and viscometry. The degree of branching of the star polymers depended on the DVB/PS‐T ratio and the PS‐T molecular weight. An asymmetric (or miktoarm) star homopolymer of the PS_nPS′_n type was made by the reaction of the PS_n symmetric star, which had n TEMPO molecules on its nucleus and consisted of a multifunctional initiator, with extra styrene. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 320–325, 2001     

Synthesis of gel type dispersion polymers via living dispersion polymerization (LDP)

A gel type disperse polystyrene/divinylbenzene (DVB) copolymer was successfully prepared in hydrocarbon via ‘living dispersion polymerization (LDP)’ method. Characterization of the dispersed polymers was performed by a combination of size-exclusion chromatographic and transmission electron microscopic analyses. Poly(t-butylstyryl)lithium with 3,5 × 10⁴ g/mol of molecular weight was used as a steric stabilizing moiety in the living dispersion polymerization. The particle size of the dispersed polymers was able to be controlled by both the mole ratio of the concentration of poly(t-butylstyryl)lithium to n-butyllithium and the amount of monomer to over 2 μm.     

Formation of hyperbranched polymers in atom transfer radical copolymerization of MMA and DVB

Hyperbranched poly(methyl methacrylate)s (HPMMAs) have been successfully prepared by atom transfer radical copolymerization of MMA and divinylbenzene (DVB). Kinetic study shows complete consumption of the initiator in 0.5 h, and relatively low polymerization rate when DVB content in the feed was high. By analyzing MALDI-TOF spectra of the resulting copolymers, the linear A _n B* (n = 0, 1, 2, 3) oligomers were formed in 0.5 h of polymerization, and then the oligomers reacted each other to form dimers, further reactions produced HPMMA. The SEC and NMR spectroscopies were used to trace the polymerization, and the results demonstrate that small amount of the branching reactions occur in the initial polymerization, and the branched polymers are significantly generated past a certain conversion depending upon the feed ratios. Raising the content of DVB in the monomer mixture can increase the pendent vinyl groups of the linear oligo-inimers, leading to gelation at low MMA conversion.     

New Polymeric Adsorbents Functionalized with Aminobenzoic Groups for the Removal of Residual Antibiotics

In this paper, we present the synthesis of new polymeric adsorbents derived from macroporous chloromethylated styrene–divinylbenzene (DVB) copolymers with different cross-linking degrees functionalized with the following aminobenzoic groups: styrene—6.7% DVB (PAB1), styrene—10% DVB (PAB2), and styrene—15% DVB (PAB3). The new polymeric products, PAB1, PAB2, and PAB3, were characterized by FTIR spectroscopy, thermogravimetric analysis, and EDX, SEM, and BET analysis, respectively. The evolution of the functionalization reaction was followed by FTIR spectroscopy, which revealed a decrease in the intensity of the γCH₂Cl band at 1260 cm⁻¹, and, simultaneously, the appearance of C=O carboxylic bands from 1685–1695 cm⁻¹ and at 1748 cm⁻¹. The thermal stability increased with the increase in the cross-linking degree. The data obtained from the EDX analysis of the novel cross-linked copolymers confirmed the functionalization with aminobenzoic groups through the presence and content of nitrogen, as follows: PAB1: N% = 0.47; PAB2: N% = 0.85; and PAB3: N% = 1.30. The adsorption performances of the novel polymeric adsorbents, PAB1, PAB2, and PAB3, were tested in the adsorption of three antibiotics, tetracycline, sulfamethoxazole, and amoxicillin, from aqueous solutions, by using extensive kinetic, equilibrium, and thermodynamic studies. The best adsorption capacity was demonstrated by the tetracycline. Amoxicillin adsorption was also attempted, but it did not show positive results.     

Studies of thermal properties of di(methacryloyloxymethyl)naphthalene–divinylbenzene (DMN–DVB) copolymer and its alkyl-bonded derivatives

This paper presents the thermal properties of highly crosslinked di(methacryloyloxymethyl)naphthalene–divinylbenzene (DMN–DVB) copolymeric microspheres containing polar groups in the structure and their alkyl-bonded derivatives. C₈ and C₁₈ alkyl chains were introduced into the aromatic rings of the DMN–DVB porous copolymer by means of the Friedel–Crafts reaction. As a source of C₈ and C₁₈ alkyl chains, octyl and octadecyl chlorides were used. It was necessary to check whether the introduction of alkyl chains into the structure of polymeric packing had an impact on its thermal properties. The studies were carried out by thermogravimetry coupled online with FTIR spectroscopy and differential scanning calorimetry in inert atmosphere (helium). It was stated that the modified materials showed 20 and 50% mass losses at higher temperatures than the non-modified one while 1% mass loss was observed at lower temperatures. Moreover, an analysis of volatile decomposition products was performed.

     

SPE for the simultaneous determination of various isothiocyanates

Several SPE sorbents were investigated for the extraction of a group of chemically diverse isothiocyanates (ITCs). They included bonded silica, carbon‐based, and polymer‐based sorbents with various functional groups. Results showed large differences in the ability of these sorbents to simultaneously extract ITCs from standard solutions. Recovery rates were on average the highest with divinylbenzene (DVB) based polymeric sorbents, especially with a DVB/N‐vinylpyrrolidone copolymer that had recovery rates ranging between 86.7 and 95.6%. These sorbents achieved the most balanced extraction efficiency between aliphatic and aromatic, polar, and nonpolar ITCs. With graphitized carbon, C₁₈‐bonded silica, and amide‐containing sorbent, recovery levels were higher for the two least polar aromatic ITCs (benzyl ITC and phenylethyl ITC), whereas for the polar aliphatic ITCs levels were the lowest. The least retained one, was methyl ITC that is the most polar with recoveries between 0 and 31.5%. The presence of amide groups, especially in a polyamide sorbent, appeared to be particularly unsuitable for the extraction of aliphatic ITCs. A copolymer made up of DVB and N‐vinylpyrrolidone was therefore shown to be the most suited for the extraction of both aliphatic and aromatic ITCs.     

Thermodegradation of poly(4-vinylpyridine-co-crotonic acid-co-divinylbenzene) and N-oxide derivatives

Copolymer networks based on 4-vinylpyridine (4VPy)/crotonic acid (CrA)/divinylbenzene (DVB) and their N-oxide derivatives have been investigated by thermogravimetric analysis (TG) to evaluate their thermal stability in nitrogen atmosphere at fixed heating rate. Thermal stability was determined from TG curves to investigate the influence of 4VPy content and introduction of N-oxide groups. The TG and DTG curves of unmodified copolymers clearly show two thermodegradation stage and the same kinetic pathway. The decomposition temperatures do not depend on the 4VPy content. The copolymers modified by oxidation present lower thermostability than unmodified showing that the introduction of N-oxide groups modifies their kinetic pathways. A kinetic model Ozawa was used to determine the kinetic parameters. The apparent thermal decomposition activation energies (ΔE_d) of the unmodified copolymer under nitrogen was higher than that in modified copolymer. Also, the characterizations of copolymer networks were done by Fourier transform infrared spectroscopy (FTIR).     

Anionic Synthesis of Heteroarm,Star-Branched Polymers. Scope and Limitations

Abstract

The scope and limitations of the following methods for the synthesis of heteroarm star-branched polymers are presented: (a) divinylbenzene linking reactions; (b) coupling reactions with macromolecular silyl halides; and (c) 1,1-diphenylethylene-based living linking reactions. The methodology of using l, 3-bis(1-phenylethenyl)benzene to prepare A₂B₂ hetero 4-armed stars is reviewed, and the synthesis of well-defined (polystyrene)₂(1,4-polybutadiene)₂ heteroarm stars is described. The synthesis of well-defined ABC heteroarm star polymers using macromonomers functionalized with 1, 1-diphenylethylene groups is described.     

Initiator‐fragment incorporation radical copolymerization of divinylbenzene and N‐isopropylacrylamide with dimethyl 2,2′‐azobisisobutyrate: Formation of soluble hyperbranched polymer nanoparticle

The copolymerization of divinylbenzene (DVB) and N‐isopropylacrylamide (NIPAm) with dimethyl 2,2′‐azobisisobutyrate of a concentration as high as 0.50 mol/L proceeded homogeneously without any gelation at 80 °C in N,N‐dimethylformamide, where the concentrations of DVB and NIPAm were 0.15 and 0.50 mol/L. The copolymer yield increased with time and leveled off over 50 min. Although DVB was consumed more rapidly than NIPAm, both comonomers were completely consumed in 50 min. The homogeneous polymerization system at 80 °C involved electron spin resonance‐observable propagating polymer radicals, the total concentration of which increased with time. The resulting copolymer was soluble in tetrahydrofuran, chloroform, acetone, ethyl acetate, acetonitrile, N,N‐dimethylformamide, dimethyl sulfoxide, and methanol, but insoluble in benzene, n‐hexane, and water. The copolymer showed an upper critical solution temperature (50 °C on cooling) in a methanol–water [11:3 (v/v)] mixture. Dimethyl 2,2′‐azobisisobutyrate fragments as high as 37–45 mol % were incorporated as terminal groups in the copolymers through initiation and primary radical termination. The contents of DVB and NIPAm were 10–30 mol % and 30–50 mol %, respectively. The intrinsic viscosity of the copolymer was very low (0.09 dL/g) at 30 °C in tetrahydrofuran despite high weight‐average molecular weight (1.2 × l0⁶ by multi‐angle laser light scattering). These results indicate that the copolymer was of hyperbranched structure. By transmission electron microscopy observation, the individual copolymer molecules were visualized as nanoparticle of 6–20 nm. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1609–1617, 2004     

Irradiation‐induced grafting of acrylonitrile onto activated carbon fiber

Viscose‐based activated carbon fiber (VACF) was modified with acrylonitrile (AN) by γ‐irradiation‐induced grafting polymerization. Effects of the grafting conditions, such as concentrations of AN and divinylbenzene (DVB), pH value, and solvent on the grafting process were studied. The physicochemical properties of the fibers were characterized. The results show that AN can be effectively grafted onto the surface of VACF with the addition of DVB. The grafting yield is higher than 12% according to thermogravimetric (TG) analysis. The study shows that DVB can improve the grafting degree of AN in the form of grafting chains or agglomerate materials. After grafting modification, VACF shows a small decrease in the specific surface area. Copyright © 2009 John Wiley & Sons, Ltd.     

Directly Fabricating Monolayer Nanoparticles on a Polymer Surface by UV‐Induced MMA/DVB Microemulsion Graft Polymerization

Summary: A sequential two‐step method was successfully used for the photografting of methyl methacrylate/1,2‐divinylbenzene (MMA/DVB) microemulsion onto the surface of a poly(propylene) (PP) film. Atomic force microscopy (AFM) images showed that nanoparticles with a cross‐section diameter of 60 nm were directly grafted onto the substrate's surface. Environment scanning electron microscope (ESEM) images proved that the particles formed just a single layer on the surface. The dormant groups on the nanoparticles' surface were a potential factor in the evolution of single layer into multilayer nanoparticles.

The surface morphology of a PP film after being grafted with a MMA/DVB microemulsion. Nanoparticles (about 60 nm in size) are clearly tethered onto the substrate's surface with just one layer.     

Synthesis of branched polystyrenes via cationic polymerisation

Branched polystyrenes have been prepared rapidly (within 15 min) and in good yields (40-99%) in dichloromethane solution at 0 °C via cationic copolymerisation of styrene (St) with divinylbenzene (DVB) using SnCl₄ as the initiator. All reaction components were deliberately used as supplied to evaluate whether such a simple approach could provide a facile synthesis of branched polymers and this has proved to be the case. The only additional experimental precaution was to avoid condensation of atmospheric moisture during the reactions. No additional chain regulating species was required to avoid crosslinking providing the St/DVB mole feed ratio was ?100/5. The intrinsic chain transfer to monomer reaction seems to be sufficient to reduce the length of the primary polymer chains and hence inhibit crosslinking and gelation in the case of the above mole feed ratios. The branching architecture of the products has been evaluated by ¹H NMR and MALS-SEC analyses.     

Efficient introduction of aromatic vinyl group by incorporation of divinylbiphenyl,p‐divinylbenzene in syndiospecific styrene polymerization using aryloxo‐modified half‐titanocene catalysts

An efficient introduction of aromatic vinyl group into syndiotactic polystyrene has been achieved by incorporation of 3,3′‐divinylbiphenyl, p‐divinylbenzene (DVB) in syndiospecific styrene polymerization using aryloxo‐modified half‐titanocenes, Cp′TiCl₂(O‐2,6‐ⁱPr₂C₆H₃) (Cp′ = ^tBuC₅H₄, 1,2,4‐Me₃C₅H₂), in the presence of MAO. The resultant polymers possessed high molecular weights with uniform molecular weight distributions, and the DVB contents could be varied by the initial feed molar ratios (6–23 mol %) without decrease in the M_n values. The syndiotactic stereo‐regularity and presence of the vinyl groups were confirmed by NMR spectra. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1902–1907