Radical polymerization behavior of 3-(N-2-methacryloyloxyethyl-N,N-dimethyl)ammonatopropanesulfonate in water

The homogeneous polymerization of 3-(N-2-methacryloyloxyethyl-N,N-dimethyl)ammonatopropanesulfonate (MDAPS) with potassium peroxydisulfate (KPS) was kinetically in situ investigated in water by means of FT-near IR spectroscopy. The overall activation energy of the polymerization was calculated to be 16.0 kcal/mol. The initial polymerization rate (R_p) at 40 °C was expressed by R_p=k[KPS]^0.65[MDAPS]^1.0. The presence of alkaline metal salts was observed to accelerate the polymerization. The order of acceleration at 40 °C was CsCl > KCl > NaCl > LiCl when the chloride salts were used. NaCl showed higher acceleration effect than NaF. NaBr and NaI exhibited retardation and inhibition effect, respectively, because of reduction of KPS and its primary radical with bromide and iodide ions. The polymerization of MDAPS with KPS in water in the presence of NaCl at 2.0 mol/l gave R_p=k[KPS]^0.70[MDAPS]^1.4 at 40 °C. The overall activation energy of the polymerization in the presence of NaCl was estimated to be 11.6 kcal/mol being considerably lower value compared with that in its absence. The syndiotacticity of poly(MDAPS) tended to increase with rising temperature and decrease in the presence of NaCl.     

Cyclic acetal-photosensitized polymerization. II. Photopolymerization of styrene in the presence of various monocyclic acetals

The polymerization of styrene (St) in benzene solution in the presence of 1,3-dioxane (DON), 1,3-dioxepane (DOP), trioxane (TRON), or tetraoxane (TEON) by means of photoirradiation of the system at 40°C has been studied kinetically from the standpoint of photosensitized polymerization. The rate of photosensitized polymerization R_p increased in the order: DOP < DON < TRON < TEON, as shown by the rate constant of decomposition of cyclic acetals, and then could be expressed by R_p = k[monocyclic acetal]^0.5[St]^1.0. The polymerization was confirmed to proceed via a radical mechanism.     

Ruthenium(III) catalysis in polymerization of vinyl monomers by charge‐transfer mechanism with aminoalcohols and carbontetrachloride: A kinetic study

The kinetics of ruthenium(III) catalyzed polymerization of vinyl monomers (M) (methyl‐, ethyl‐, and butylacrylates) by charge‐transfer mechanism with aminoalcohols (AA) (namely, ethanol‐, diethanol‐, and triethanol amines) and carbontetrachloride in dimethylsulfoxide medium have been studied. The rate of polymerization depends on the [CCl₄]/[AA] ratio and may be represented as and The rate of polymerization of monomers with each aminoalcohol was found to be in the order R_p (methyl‐)> R_p (ethyl‐)> R_p (butylacrylate) while that of each monomer with different aminoalcohols was found to be in the order of R_p tertiary > R_p secondary > R_p primary aminoalcohol. The suitable mechanism for the polymerization process consistent with kinetic data has been proposed. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 585–592, 2006     

Radical polymerization of 2-methacryloyloxyethyl phosphorylcholine in water: kinetics and salt effects

The homogeneous polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) as betaine monomer with potassium peroxydisulfate (KPS) was kinetically investigated in water by means of FT-near IR spectroscopy. The overall activation energy of the polymerization was estimated to be 12.8 kcal/mol. The initial polymerization rate (R_p) at 40 °C was given by R_p = k[KPS]^0.98[MPC]^1.9. The presence of alkaline metal halides accelerated the polymerization. The larger the radius of metal cation or halide ion was, the larger the accelerating effect was. The accelerating salt effect was explained by interactions of salt ions with ionic moieties of the propagating polymer radical and/or the MPC monomer. A kinetic study was also performed on the polymerization of MPC with KPS in water in the presence of NaCl of 2.5 mol/l. R_p at 40 °C was expressed by R_p = k[KPS]^0.6[MPC]^1.6. A very low value of 4.7 kcal/mol was obtained as the overall activation energy of the polymerization.     

Conformational and neighboring effects in graft polymerization of acrolein onto imidazole-containing polymer

The graft polymerizations of acrolein (AL) onto an imidazole (Im)-containing polymer, such as a homopolymer of 4(5)-vinylimidazole (VIm) and several copolymers of VIm-methyl vinyl ketone, VIm-butyl acrylate, and VIm-2-ethyl hexyl acrylate, have been kinetically carried out in ethanol-water mixture at 0°C. The graft polymerization rate R_p and the degree of graft polymerization increased with increasing concentration of water in the solvent. Moreover, the R_p of the copolymer system having the hydrophobic group as the side chain decreased in comparison with the homopolymer system. Polymerizations of AL in the presence of propionamide or poly-acrylamide (AAm) induced by Im were also kinetically carried out in ethanol-water mixture. The R_p was also affected by the conformational change of poly-AAm. These results were discussed by assuming the conformation of the parent polymer in ethanol-water mixture.     

Radical polymerization behavior of ethyl ortho-formylphenyl fumarate involving intramolecular hydrogen abstraction

The radical polymerization behavior of ethyl ortho-formyl-phenyl fumarate (EFPF) using dimethyl 2,2′-azobisisobutyrate (MAIB) as initiator was studied in benzene kinetically and ESR spectroscopically. The polymerization rate (R_p) at 60°C was given by R_p = k[MAIB]^0.76[EFPF]^0.56. The number-average molecular weight of poly(EFPF) was in the range of 1600–2900. EFPF was also easily photopolymerized at room temperature without any photosensitizer probably because of the photosensitivity of the formyl group of monomer. Analysis of ¹H? and ¹³C-NMR spectra of the resulting polymer revealed that the radical polymerization of EFPF proceeds in a complicated manner involving vinyl addition and intramolecular hydrogen-abstraction. The polymerization system was found to involve ESR-observable poly(EFPF) radicals under the actual polymerization conditions. ESR-determined rate constant (2.4–4.0 L/mol s) of propagation at 60°C increased with decreasing monomer concentration, which is mainly responsible for the observed low de-pendency of R_p on the EFPF concentration. Copolymerizations of EFPF with some vinyl monomers were also examined. © 1995 John Wiley & Sons, Inc.     

Radical polymerization behavior of vinyl phenylsufonylacetate

Vinyl phenylsulfonylacetate (VPSA) was prepared by the reaction of vinyl chloroacetate with sodium benzenesulfinate in acetone in the presence of a phase-transfer catalyst. VPSA showed a high radical homopolymerizability similar to vinyl acetate in spite of the fact that VPSA carries a phenyl group. The polymerization of VPSA with 2,2^′-azobisisobutyrate (MAIB) was kinetically investigated in acetone. The overall activation energy of the polymerization was 27.6 kcal/mol. The polymerization rate (R_p) at 50 °C was expressed by R_p=k[MAIB]^0.67[VPSA]^1.1. Poly(VPSA) showed exothermic (27 °C) and endothermic (57 °C) peaks in its DCS curve, corresponding to crystallization and melting. The tacticity of poly(VPSA) was estimated to be rr=29, mr=49, and mm=22.     

Cyclic Acetal-Photosensitized Polymerization. 9. Photopolymerization of Triallylidene Sorbitol

Abstract

The photopolymerization of triallylidene sorbitol (TAS) was carried out in benzene at 40°C without the usual initiator. The polymerization of TAS was found to be initiated with the ester radical generated via the acetal radical from TAS by means of photoirradiation. The rate of polymerization and the molecular weight of polymer were small due to the degradative chain transfer, It was kinetically investigated from the standpoints of the degradative chain transfer by the allylidene group and the cyclization by three double bonds. The following results were obtained: (1) The relation between the rate of polymerization, R_p, the monomer concentration, [M], could be expressed by [M] /R_p = (A[M] + B)/(3[M] + C), where A, B, and C were constant; (2) the ratio of the rate constant of unimolecular cyclization to the total rate constant of bimolecular propagation and the chain transfer of uncyclized radical was estimated to be 3.0 mol/dm³. A small amount of cyclopolymerization took place.     

Interaction of several polymers with p-substituted phenols in aqueous solution

The interactions between several water-soluble polymers, i.e., polyethyleneimine (PEI), poly-(ethylene glycol) (PEG), polyacrylamide (PAM), and poly(methacrylic acid) (PMAA), and p-X-substituted phenols (X = CH₃O, CH₃ C₂H₅, H, Cl, Br and NO₂) in aqueous solution at 30°C were investigated by means of equilibrium dialysis. By applying the Klotz equation to the results obtained, the bonding constants between these polymers, including poly(vinylpyrrolidone) (PVP) which was reported previously, and phenol were determined; they decreased in the following order: PVP > PMAA > PEI > PAM > PEG. This order was in agreement with that reported from the solubility of naphthalene, biphenyl, and alkyl halides in aqueous solution of these polymers caused by a hydrophobic bonding interaction. In this case, therefore, a hydrophobic bonding seemed to be significant. The bonding constants of these polymers with p-substituted phenols were also determined, and they were found to be approximately correlated with Hamett σ constants of the para substituents in phenols. Therefore, it was concluded that the interactions due to electrostatic and hydrogen-bonding forces were also important.     

Long-lived polymer radicals. VI. Polymerization of N-methylmethacrylamide with formation of living propagation radicals

The polymerization of N-methylmethacrylamide (NMMAm) with azobisisobutyronitrile (AIBN) was investigated kinetically in benzene. This polymerization proceeded heterogeously with formation of the very stable poly(NMMAm) radicals. The overall activation energy of this polymerization was calculated to be 23 kcal/mol. The polymerization rate (R_p) was expressed by: R_p = k[AIBN]^0.63-0.68[NMMAm]^1?2.5. Dependence of R_p on the monomer concentration increased with increasing NMMAm concentration. From an ESR study, cyanopropyl radicals escaping the solvent cage were found to be converted to the living propagating radicals of NMMAm in very high yields (ca. 90%). Formation mechanism of the living polymer radicals was discussed on the basis of kinetic, ESR spectroscopic, and electron microscopic results.     

Conformational and neighboring effects in graft polymerization of acrolein on 4(5)-vinylimidazole-acrylamide copolymer

The graft polymerization of acrolein (AL) on poly-4(5)-vinylimidazole or the copolymers of 4(5)-vinylimidazole(VIm) and acrylamide of varying composition were carried out kinetically in an ethanol–water mixture at 0°C. The graft polymerization rate R_p increased with an increasing concentration of water in the solvent. On the other hand, the R_p of the copolymer which incorporated 50 mol % VIm showed the highest value. These results were discussed by assuming interaction between amide and imidazole groups in copolymer.     

Aqueous polymerization of acrylonitrile by ascorbic acid–peroxodisulfate redox system

The polymerization of acrylonitrile initiated by an ascorbic acid–peroxodisulfate redox system was studied in an aqueous solution at 35°C in the presence of air. Molecular oxygen was found to have no effect on the polymerization reaction. An increase in ionic strength slightly increased the rate. The overall rate of polymerization, R_p, showed a square dependence on [monomer] and a half-order dependence on [peroxodisulfate]. A first-order dependence on [ascorbic acid] at low concentrations (<3.0 × 10^?3 mol L^?1) followed by a decrease in R_p at higher concentrations of ascorbic acid (>3.0 × 10^?3 mol L^?1) was also noted. R_p remained unchanged up to 40°C and showed a decline thereafter. Addition of catalytic amounts of cupric ions decreased the rate whereas ferric ions were found to increase the rate. Added sulfuric acid in the range (6.0?50.0) × 10^?5 mol L^?1 decreased the R_p.     

Retardation of Permanganate-Initiated Polymerization of Acrylonitrile by Phenol

The mechanism and kinetics of the retardation of the permanganate-initiated polymerization of acrylonitrile by phenol have been studied in the temperature range of 30 to 45°C. The effect of monomer, metal ion, phenol, sulfuric acid, organic solvents, and some inorganic salts on the polymerization has been studied. The most remarkable observation in the present investigation was the negative intercept obtained from a plot of [M]/R_p versus 1/[M] of the rate mechanism, This observation appears to be a general phenomenon for all inhibiting substrates. A reaction mechanism has been suggested and a suitable rate law has been proposed.     

Heterocyclic Ylide-Initiated Polymerization of Methyl Acrylate

β-Picolinium-p-chlorophenacylide initiates radical polymerization of methyl acrylate (MA) up to 19.5% conversion without gelation due to autoacceleration. The average rate of polymerization (R_p) increases as [ylide] is raised from 1.02 to 3.06 mmol/L, the order of reaction being 0.5 ± 0.02. However, at higher concentrations (>3.06 mmol/L), R_p decreases. The monomer exponent is 1.40 when benzene is used as diluent. The overall energy of activation is computed to be 28.8 kJ/mol. A polar solvent like dimethyl-sulfoxide and a radical scavenger like hydroquinone retard the reaction. The kinetic data and ESR studies indicate that the polymerization proceeds via a free-radical mechanism. Chain termination by degradative chain (initiator) transfer appears to be significant.     

Polymer effect in graft polymerizations of acrolein onto imidazole-containing polymer

The graft polymerizations of acrolein (AL) onto an imidazole (Im)-containing polymer, such as a homopolymer of 4(5)-vinylimidazole (VIm) and several copolymers of VIm-4-vinylpyridine (VPy), VIm-1-vinyl-2-pyrrolidone (VPr), and VIm-styrene (St), have been studied in ethanol at 0°C. The degree of polymerization (P?_n) of the resulting polyacrolein graft depended on the number of Im units in the Im-containing polymer which produced a decrease in P?_n of grafted polyacrolein. The P?_n of the graft polyacrolein was determined to be in the range of 5-23. The rate of polymerization (R_p) was expressed by R_p = k(PVIm) (AL)². The graft polymerizability of the AL was influenced by the comonomer in the parent polymer, and was found to be in the order of VIm homopolymer > VIm-VPr copolymer > VIm-VPy copolymer > VIm-St copolymer. R_p was affected by the functional group around the Im group in the Im-containing polymer. These results were discussed by assuming the conformation of the parent polymer in ethanol.     

Metal-Containing Initiator Systems. 30. Vinyl Polymerization Initiated with Bis(ethyl acetoacetato)copper(II) and Maleimide

Some electron-accepting compounds such as maleimide (MIm), maleic anhydride (MAn), and tetracyanoquinodimethane were found to show pronounced accelerating effects on vinyl polymerization initiated with metal chelates. The polymerization of methyl methacrylate (MMA) initiated with bis(ethyl acetoacetato)-copper(II) (Cu(eacac)₂) and MIm was studied kinetically in benzene. The overall activation energy of the polymerization was calculated to be 11.5 kcal/mol. This value was much lower than that (17.6 kcal/mol) for the polymerization of MMA with Cu(eacac)₂ alone. The polymerization rate (R_p) was expressed as R_p =k[MIm]^1/2 [Cu(eacac)₂]^1/2 [MMA] The first-order dependence of R_p on the monomer concentration indicated that the monomer had no participation in the initiation step, in contrast with polymerization in the absence of MIm (where a monomer concentration dependence of 1.4th order was observed). Electronic spectroscopic study revealed that a complex between MIm and Cu(eacac)₂ had been formed. The ligand radical, an acetylcarboethoxymethyl radical, was trapped by 2-methyl-2-nitrosopropane in the reactions of Cu(eacac)₂ with MIm and with MAn in benzene. From these results the mechanism of the initiation of polymerization is discussed.     

Vinyl polymerization with a binary system of p‐chlorobenzenediazonium salt and sodium tetraphenylborate

A combined system of sodium tetraphenylborate (STPB) and p‐chlorobenzenediazonium tetrafluoroborate (CDF) serves as an effective initiator at low temperatures for acrylate monomers such as methyl methacrylate (MMA), ethyl acrylate, and di‐2‐ethylhexyl itaconate. The polymerization of MMA with the STPB/CDF system has been kinetically investigated in acetone. The polymerization shows a low overall activation energy of 60.3 kJ/mol. The polymerization rate (R_p) at 40 °C is given by R_p = k[STPB/CDF]^0.5[MMA]^1.6, when the molar ratio of STPB to CDF is kept constant at unity, suggesting that STPB and CDF form a complex with a large stability constant and play an important role in initiation and that MMA participates in the initiation process. From the results of a spin trapping study, p‐chlorophenyl and phenyl radicals are presumed to be generated in the polymerization system. A plausible initiation mechanism is proposed on the basis of kinetic and electron spin resonance results. A large solvent effect on the polymerization can be observed. The largest R_p value in dimethyl sulfoxide is 11 times the smallest value in N,N‐dimethylformamide. The copolymerization of MMA and styrene with the STPB/CDF system gives results somewhat different from those of conventional radical copolymerization. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4206–4213, 2001     

Polymerization of methyl methacrylate by charge-transfer mechanism with aliphatic primary amines and carbon tetrachloride

Polymerization of methyl methacrylate (MMA) with aliphatic primary amines and carbon tetrachloride has been investigated in th dimethylsulfoxide medium by employing a dilatometric technique at 60°C. The rate of polymerization (R_p) has been evaluated under the conditions, [CCl₄]/[amine] < 1 and > 1. The kinetic data indicate possible participation of the charge transfer complexes formed between the amine + CCl₄ and the amine + MMA in the polymerization of MMA. In the absence of CCl₄ or amine, no polymerization of MMA was observed under the present experimental conditions. The polymerization of MMA was inhibited by hydroquinone, indicating a free radical initiation. The energy of activation varied from 32 to 58 kJ mol^?1.     

Polymerization of Acrylonitrile Initiated by the System Tetramethyl-2-tetrazene and p-Toluenesulfonic Acid

The polymerization of acrylonitrile (AN) initiated by tetramethyl-2-tetrazene (TMT) and p-toluenesulfonic acid (TSA) in dimethylformamide (DMF) was studied. The polymerization was confirmed to proceed through a radical mechanism. The initial rate of polymerization R was expressed by the equation: R_p = k[TMT]^0.6 [TSA]^0.46 [AN]^1.35. The overall activation energy for the polymerization was estimated as 20.7 kcal/mole. In the absence of monomer, the reaction of TMT with TSA was also studied kinetically by measuring the evolution of nitrogen. From these results and ESR measurement of the TMT/TSA system, a possible initiation mechanism is proposed.     

Kinetic and ESR studies on the radical polymerization of α‐n‐(α′‐methylbenzyl) β‐ethyl itaconamates derived from racemic and (s)‐α‐methylbenzylamines

The polymerization of α‐N‐(α′‐methylbenzyl) β‐ethyl itaconamate derived from racemic α‐methylbenzylamine (RS‐MBEI) by initiation with dimethyl 2,2′‐azobisisobutyrate (MAIB) was studied in methanol kinetically and with ESR spectroscopy. The overall activation energy of polymerization was calculated to be 47 kJ/mol, a very low value. The polymerization rate (R_p ) at 60 °C was expressed by R_p = k[MAIB]^0.5±0.05[RS‐MBEI]^2.9±0.1. The rate constants of propagation (k_p ) and termination (k_t ) were determined by ESR. k_p was very low, ranging from 0.3 to 0.8 L/mol s, and increased with the monomer concentration, whereas k_t (4–17 × l0⁴ L/mol s) decreased with the monomer concentration. Such behaviors of k_p and k_t were responsible for the high dependence of R_p on the monomer concentration. R_p depended considerably on the solvent used. S‐MBEI, derived from (S)‐α‐methylbenzylamine, showed somewhat lower homopolymerizability than RS‐MBEI. The k_p value of RS‐MBEI at 60 °C in benzene was 1.5 times that of S‐MBEI. This was explicable in terms of the different molecular associations of RS‐MBEI and S‐MBEI, as analyzed by ¹H NMR. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4137–4146, 2000