Polymerization Of Vinyl Monomers Research Articles

Poly(styrene peroxide) and Poly(methyl methacrylate peroxide) for Grafting on Unsaturated Bacterial Polyesters

A new soluble terephthaloyl oligoperoxide (OTP) was synthesized by the reaction of terephthaloyl peroxide and 2,5-dimethyl 2,5-dihydroperoxy hexane. Thermal polymerization of vinyl monomers (styrene, methyl methacrylate) with OTP yielded poly(styrene peroxide) (PS-P) and poly(methyl methacrylate peroxide) (PMMA-P) which are used in the grafting reactions onto medium chain length unsaturated bacterial polyester obtained from soybean oily acids with Pseudomonas oleovorans poly(3-hydroxy alkanoate), (PHA). PS-g-PHA and PMMA-g-PHA graft copolymers isolated from related homopolymers were characterizated by 1H NMR spectrometry, FT-IR spectroscopy, thermal analysis and gel permeation chromatographic (GPC) techniques. Swelling measurement of the crosslinked graft copolymers were also measured to calculate qv values.

Ethoxylated nonyl phenols and ethoxylated fatty alcohols–ceric ion redox systems for aqueous polymerization of vinyl monomers

Ethoxylated nonyl phenols, ethoxylated fatty alcohols, and ceric ammonium nitrate redox systems were used for the polymerization of vinyl and acrylic monomers such as acrylonitrile, styrene, and acrylic acid. The initiating radical was formed on reducing organic compound which in turn initiated polymerization to give polymers containing chain ends of ethoxylated nonyl phenols and ethoxylated fatty alcohols that showed much higher water absorption. The effects of the concentration of Ce+4 salt, ethoxylated nonyl phenols, and monomers on both the yield and the molecular weight of corresponding polymers were studied. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 310–313, 2001

Synthesis of Inorganic/Organic Host−Guest Hybrid Materials by Cationic Vinyl Polymerization within Y Zeolites and MCM-41

Cationic guest polymerizations of several vinyl monomers inside the pores of HY zeolites and MCM-41 as hosts have been used for the synthesis of novel organic/inorganic hybrid materials. Substituted vinyl ethers [ROCHCH2; R = −CH2CH(CH3)2, −C2H5, −C2H4Cl, −C6H11], 2,3-dihydrofuran, and N-vinylcarbazole can serve this purpose, because their polymerization can be initiated by the active protons in HY zeolite or by coadsorbed arylmethylium ions in MCM-41. The synthesis of well-defined poly(vinyl ethers) or poly(vinylcarbazole) under the conditions of constricted geometry can be achieved by means of cationic host−guest polymerization of the corresponding monomers in MCM-41 (pore diameter 3.6 nm) with (4-CH3OC6H4)2CHCl (MeO) or (C6H5)3CCl (TC) as the internal surface initiator. The reaction products are novel polymer/MCM-41 host−guest hybrid materials. The molecular mass of the (enclosed) polymer and the percentage of polymer within the pores of MCM-41 as well as HY zeolite can be adjusted within certain limit...

Radical polymerisation of vinyl monomers initiated by the thermolysis of alkene ozonates

Radicals, derived from the ozonates of alkenes, have been shown to be capable of initiating polymerisations of methyl methacrylate, styrene and vinyl acetate: in the case of styrene polymerisations the molar masses obtained at low conversion did not follow the expected trend with temperature.

Reverse atom transfer radical polymerization of vinyl monomers with Fe[SC(S)NEt2]3 alone as the catalyst

AbstractThe living radical polymerization of methyl methacrylate and styrene was successfully carried out with diethyl 2,3‐dicyano‐2,3‐diphenylsuccinate (DCDPS)/ferric tri(diethyldithiocarbamate) as a novel reverse atom transfer radical polymerization initiation system in which DCDPS was a hexa‐substituted ethane‐type thermal iniferter, DC was a diethyldithiocarbamate group, and no additional ligands such as nitrogen‐ or phosphine‐based compounds were required. The bulk polymerization of methyl methacrylate was carried out at 95 °C, and that of styrene was carried out at 120 °C. Poly(methyl methacrylate) and polystyrene (PSt) with high molecular weights and quite narrow molecular weight distributions (as low as 1.09 for PSt) were obtained. 1H NMR spectroscopy revealed the presence of an α‐(carbethoxycyanophenyl)methyl group from the initiator and an ω‐DC group from the catalyst in the obtained polymers. Various chain‐extension reactions under UV light or thermal treatments were successfully conducted to prove the presence and efficient reinitiating of the ω‐DC group. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3464–3473, 2001

Polymerization of Vinyl Monomers Using Oxidase Catalysts

Polymerization of vinyl monomers using oxidase as catalyst has been performed under argon in the presence of acetylacetone as a mediator and without the use of hydrogen peroxide. The polymerization of acrylamide was catalyzed by a laccase or sarcosine oxidase catalyst in distilled water and efficiently produced the polymer with high molecular weight. In the polymerization using the laccase catalyst, the effects of temperature, time, and amounts of enzyme and mediator have been systematically investigated. On the other hand, various other oxidases such as bilirubin, choline, and xanthine oxidases showed no or little activity for the vinyl polymerization. The laccase/acetylacetone catalyst induced the polymerization of methyl methacrylate and styrene in a mixture of water and tetrahydrofuran. Laccase alone also acted as a catalyst for the vinyl polymerization of acrylamide and methyl methacrylate without acetylacetone. In the polymerization of methyl methacrylate using lipoxidase as the catalyst in the presence of acetylacetone, the reaction occurred in air.

Ethoxylated nonyl phenols and ethoxylated fatty alcohols-ceric ion redox systems for aqueous polymerization of vinyl monomers

Ethoxylated nonyl phenols, ethoxylated fatty alcohols, and ceric ammonium nitrate redox systems were used for the polymerization of vinyl and acrylic monomers such as acrylonitrile, styrene, and acrylic acid. The initiating radical was formed on reducing organic compound which in turn initiated polymerization to give polymers containing chain ends of ethoxylated nonyl phenols and ethoxylated fatty alcohols that showed much higher water absorption. The effects of the concentration of Ce+4 salt, ethoxylated nonyl phenols, and monomers on both the yield and the molecular weight of corresponding polymers were studied. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 310–313, 2001

A New Additive for Controlled Radical Polymerization

A new versatile additive for the controlled radical polymerization of numerous vinyl monomers under mild conditions is presented. The addition of 1,1-diphenylethene (DPE) to a conventional radical polymerization system consisting of initiator and monomer results in a controlled behavior of the polymerization. Block copolymers are obtained by simply heating the resulting polymers in the presence of a second monomer.

A New Additive for Controlled Radical Polymerization

A new versatile additive for the controlled radical polymerization of numerous vinyl monomers under mild conditions is presented. The addition of 1,1-diphenylethene (DPE) to a conventional radical polymerization system consisting of initiator and monomer results in a controlled behavior of the polymerization. Block copolymers are obtained by simply heating the resulting polymers in the presence of a second monomer.

On the Connection between Microstructure and Kinetics of (Pseudo)copolymerization

The connection between microstructure and kinetics in the case of irreversible growth of long (pseudo)copolymers has been discussed, extended and established. The theoretical results have been cast in simple matrix equations which enable one to compute the probability to find any given sequence in terms of ratios of kinetic constants, rather than in terms of stochastic parameters. As an application, the case of regioregular polymerization of vinyl monomers by C1-symmetric coordination catalysts has been considered. In addition to propagation, first order in monomer concentration, chain and site epimerization, both zeroth-order in monomer concentration, have been taken into account. The resulting equations have been tested against a set of literature data obtained by five different catalysts, each operated at five different concentrations, resulting in the evaluation of ratios of kinetic constants. For all catalysts the quantitative analysis of the kinetics confirms that the contribution of chain epimeriza...

Synthesis and characterization of star polymers initiated by hexafunctional discotic initiator through atom transfer radical polymerization

AbstractA novel hexafunctional discotic initiator, 2,3,6,7,11,12‐hexakis(2‐bromobutyryloxy)triphenylene (HBTP), was synthesized by the esterification of 2,3,6,7,11,12‐hexahydroxytriphenylene with 2‐bromobutyryl chloride. Atom transfer radical polymerizations of styrene, methyl acrylate, and n‐butyl acrylate were carried out in 50 vol % tetrahydrofuran with HBTP/copper(I) bromide/2,2′‐bipyridyl as an initiation system. The polymers produced had well‐controlled molecular weights and narrow molecular weight distributions (<1.2). On the basis of 1H NMR spectra of the star polymer and its hydrolyzed products, we can conclude that the initiator quantitatively initiated the polymerization of vinyl monomers and that a star polymer with a discotic core was obtained. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2233–2243, 2001

Evaluation of ruthenium-based complexes for the controlled radical polymerization of vinyl monomers

New complexes of the type RuCl2(p-cymene)L where the ligand L is either a phosphine or a stable triazolinylidene carbene have been tested and compared to the Grubbs' benzylidene complex RuCl2(=CHPh)(PCy3)2 as catalyst precursors for the controlled atom transfer radical polymerization (ATRP) of methyl methacrylate and of various para-substituted styrenes. Kinetic data and Hammett ρ constants are reported, as well as the X-ray structure of the ortho-metallated triazolinylidene-ruthenium(II) complex RuCl(p-cymene)[1,2-phenylene[3,4-diphenyl-1H-1,2,4-triazol-1-yl-5(4H)-ylidene]].Key words: ruthenium, carbene, chelate complex, homogeneous catalysis, atom transfer radical polymerization.

In‐Situ Kinetic Pursuit of Emulsion Crosslinking Copolymerizations of Monomethacrylate and Dimethacrylate by Means of ReactIR®

The usefulness of tthe ReactIR® reaction analysis system as a powerful tool to in situ monitor the kinetics of the emulsion polymerization of vinyl monomers was verified by comparison with the conventional gravimetric method and by checking the rate dependencies on the initiator and surfactant concentrations in the emulsion polymerization of butyl methacrylate (BMA). The system was then applied to the kinetic monitoring of emulsion crosslinking copolymerizations of monomethacrylate and dimethacrylate, including methyl methacrylate/ethylene dimethacrylate and BMA/1,6- hexanediol dimethacrylate systems of different hydrophilicitics.

Polymerization of methyl methacrylate and styrene in presence of phthalides

The radical polymerization of vinyl monomers (methyl methacrylate, styrene) has been investigated in the presence of phthalides of different structure. It is shown that the phthalides containing halogen atoms are, first of all, chain-transfer agents. The values of chain-transfer constants to them have been determined. It was found that the presence of chlorine atom bounded directly with carbon of phthalide cycle in a phthalide molecule results in considerable growth of chain-transfer constant value to phthalide. If the halogen is connected with aromatic group of phthalide, phthalide is a weak chain-transfer agent and the phthalide cycle is not included in polymer molecule. It is shown that the phthalides containing mobile atoms of hydrogen can take part both in chain-transfer and in initiating system formation with the initiator. The function of phthalide is determined by structure of phthalide, monomer and initiator. The mechanism of phthalide participation in polymerization has been discussed. The solutions of poly-MMA containing phthalide groups in macromolecules in concentrated sulfuric acid are intensively colored. This fact was used for quantitative determination of phthalide cycles in a polymer chain. It has been found that when UV irradiated the bulks of poly-MMA fluoresce and phosphoresce in a visible part of spectrum.

60Co γ-Irradiation-Initiated “Living” Free-Radical Polymerization in the Presence of Dibenzyl Trithiocarbonate

The free-radical polymerization of vinyl monomers in the presence of dibenzyl trithiocarbonate (DBTTC) and under 60 Co γ-irradiation is of living character. Under 60 Co irradiation, the bonds between benzyl group and sulfur were cleaved, benzyl radicals initiate the polymerization. The propagating radical together with trithiocarbonate radicals form a dormant polymer chain. The fast equilibrium between propagation radical and dormant polymer chain controls the polymerization.

β-Nitrostyrene Derivatives as Inhibitors of the Free Radical Polymerization

The free radical polymerization of vinyl monomers is efficiently inhibited by β-nitrostyrene derivatives. The high reactivity of the growing radicals towards the β-nitro compounds is controlled by the electron-donor character of the macroradical and the electron deficiency of the double bond of the β-nitro derivative. Electron withdrawing substituents at the 4-position of β-nitrostyrene increase markedly the inhibition rate. The inhibition efficiency of β-nitrostyrenes towards electron deficient monomer double bonds is strongly reduced. Polymerization rates and 1H NMR results show that the β-nitrostyrene derivatives act as strong inhibitors of the polymerization through a mechanism that involves the release of NO2.

Catalytic Oxidative Polymerization of Vinyl Monomers Using Cobalt Phthalocyanine Complex and an Exploratory Investigation on the Polymerization of Vinyl Acetate

This is the first report on the oxidative polymerization of vinyl monomers using cobalt(II) phthalocyanine pyridine {CoIIPc(Py)} complex. The mechanism of polymerization is described and it has been supported from the kinetic data, UV−vis, ESR and 1H NMR studies. It is found that the rate of polymerizations (Rp) and number-average molecular weights (M̄n) of the vinyl polyperoxides are higher for CoIIPc(Py) catalyzed polymerization compared to the usual free radical, AIBN, initiated polymerization. This is supported by their activation energy of initiation (Ei) and total activation energy (Ea) of polymerization. The peroxide macroinitiator has been used for the polymerization of vinyl acetate. The polymerization obeys classical kinetics. The K2 values of the peroxide macroinitiator has been determined, which reveals that it can also be used at higher temperature for the polymerization compared to monomeric peroxide initiator, benzoyl peroxide. The “active” poly(vinyl acetate) has also been synthesized, which contains peroxy segments at the chain ends.

Inclusion Polymerization in Polymorphic Crystals of Cholic Acid

Inclusion polymerization of vinyl and diene monomers was studied using cholic acid (CA) as host. Polymorphism of CA inclusion crystals was found to play a decisive role in the polymerizability of the monomers. Polymorphic crystals were obtained by recrystallization and guest-exchange on intercalation. In the case of methacrylonitrile, CA forms two crystal structures; a bilayer structure with one-dimensional channels and crossing structure with cagelike cavities. The former structure is suitable for polymerization, but not the latter. In the case of 2,3-dimethyl-1,3-butadiene, intercalation yielded only bilayer crystals. The microstructure of the resulting polymer was compared with those of the polymers obtained by other steroidal hosts. Different stereoregularity may be explained on the basis of different channel sizes of hosts.

Novel phenomenon of autoacceleration in the free radical oxidative polymerization of vinyl monomers: a thermochemical approach

A unique phenomenon of ‘autoacceleration’ was observed in a free radical polymerization of vinyl monomers and oxygen. Unlike the well known autoacceleration phenomenon in polymerization processes, this unusual phenomenon is not readily conceivable in terms of solution viscosity based reasoning. Surprisingly, we have observed manifestation of this new autoacceleration during free radical oxidative polymerization of some vinyl monomers at low conversions, where generally the polymerization reaction is zero order, the conversion–time plot are linear and viscosity effects are negligible. In the present paper, we interpret the mechanism of this new autoacceleration phenomenon on the basis of reactivity of the propagating radicals in terms of heat of formation data.

Copolymerization of Vinyl Monomers with Different Water Solubilities in the Presence of Manganese Sulfonate Complexes

Mixed-ligand Mn(III) complexes were prepared from manganese tris(acetylacetonate) and alkyl- benzenesulfonic acid, and their surface activity and initiating power with respect to polymerization of vinyl monomers differing in reactivity and water solubility were studied.