P-acetyl Benzylidene Triphenylarsonium Ylide Research Articles

Effect of Novel Superplasticizer on Workability and Strength of Ready Mixed Concrete

With the advent of superplasticizers, dream to discover method of making ready mixed concrete at the lowest possible water cement ratio while maintaining a high workability has achieved. In addition, these concrete material are also suitable for use with other cementations materials like fly ash. Poly(styrene-co-acrylonitrile) prepared with the help of p-acetyl benzylidene triphenyl arsonium ylide had made it possible, the production of concrete at low water cement ratio. Many waste materials of today become the useful by products of tomorrow water cement ratio was maintained between 0.38-0.47. Use of fly ash in concrete improves the penetration rate of CO 2 or chloride ions. The result have shown substantial improvement in the properties of concrete after use of copolymer of styrene and acrylonitrile as superplasticizer.

Accelerating effect of arsonium ylide for the copolymerization of acrylonitrile and α-methyl styrene

p-Acetyl benzylidene triphenyl arsonium ylide (p-ABTAY) accelerates α,α-azobisisobutyronitrile (AIBN) initiated copolymerization of acrylonitrile (AN) and α-methyl styrene (α-MS) in DMF at 65 ± 0.1 °C by reducing the rate of termination. The value of energy of activation in the presence and absence of p-ABTAY is 11.0 and 9.8 kJ/mol, respectively.

P-Acetylbenzylidene triphenylarsonium ylide initiated radical polymerization of methyl acrylate

Polymerization of methyl acrylate (MA), initiated by p-acetyl benzylidene triphenylarsonium ylide (p-ABTAY) in dioxan at (60 ± 1)°C for 1 h, follows nonideal kinetics (Rp ∝ [I]0.21[M]1.40) due to primary radical termination as well as degradative chain transfer reaction. The polymerization proceeded upto 20.49% conversion without gelation and results in the polymer of high molecular weight 98,000. The overall activation energy and the value of kp2/kt are 14 kJ mol–1 and 18.75 × 10–6 L mol–1 s–1, respectively. The ylide dissociates to form phenyl radical, which initiates the polymerization of MA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Synthesis and characterization of co-polymers of styrene with acrylonitrile initiated by p-acetylbenzylidene triphenylarsonium ylide

p-Acetylbenzylidene triphenylarsonium ylide (p-ABTAY) initiated free radical co-polymerization of styrene (Sty) with acrylonitrile (AN) in dioxane, at 60 ± 0.1°C for 1 h, under the inert atmosphere of nitrogen results an alternating co-polymer. The system follows ideal kinetics (R p α [p-ABTAY]0.5 [Sty] [AN]). The activation energy has been computed to be 30 kJ/mol. The FT-IR spectra of the co-polymers show bands at 3054 cm−1 and 2238 cm−1 due to styrene and acrylonitrile, respectively. The 13C-NMR spectra of the co-polymer show peaks at 120–123 δ ppm and 127–132 δ ppm due to —CN of acrylonitrile and phenyl carbon of styrene, respectively. The reactivity ratios have been calculated, using the Kelen–Tüdos method, to be r 1(Sty)= 0.0067 and r 2 (AN)= 0.082. The formation of phenyl radicals may be attributed to the p π –d π overlap between the hybridized sp2 orbital and more diffused 4d orbital of arsenic.

Free radical copolymerization of styrene with vinyl acetate using p‐acetylbenzylidene triphenylarsonium ylide as an initiator

Abstractp‐Acetylbenzylidene triphenylarsonium ylide (p‐ABTAY) initiated free radical copolymerization of styrene (Sty) with vinyl acetate (VA) in dioxane, at 65 ± 0.1°C, under the inert atmosphere of nitrogen has been studied. The system follows ideal radical kinetics and the kinetic equation for the system is Rp ∝ [p‐ABTAY]0.5[Sty][VA]. The rate of copolymerization (Rp) is proportional to the square root of [p‐ABTAY] indicating biomolecular termination. The values of kp2/kt and energy of activation have been computed as 5.0 × 10−3 mol l−1 s−1 and 34.0 kJ mol−1 respectively. The reactivity ratios calculated by using Kelen–Tudos method are r1(Sty) = 42.8, r2(VA) = 1.0. SEM analysis shows that arsenic is not incorporated in the polymer and the copolymerization reaction is initiated by phenyl free radicals. The formation of phenyl radicals may be attributed to the pπ–dπ overlap between the hybridized sp2 orbital and more diffused 4d orbital of arsenic. © 2002 Wiley Periodicals, Inc. Adv Polym Techn 21: 108–115, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/adv.2000

P-ACETYLBENZYLIDENE TRIPHENYLARSONIUM YLIDE (p-ABTAY) INITIATED RADICAL COPOLYMERIZATION OF METHYLMETHACRYLATE WITH STYRENE

p-Acetylbenzylidene triphenylarsonium ylide (p-ABTAY) initiated radical copolymerization of methylmethacrylate (MMA) with styrene in dioxane, at 60 ± 0.1°C, under the inert atmosphere of nitrogen yields alternating copolymer, as evidenced by 1H NMR spectroscopy. The kinetic equation for the present system is Rp μ[p-ABTAY]0.46 [MMA] [Sty]. The rate of copolymerization (Rp) is proportional to the square root of [p-ABTAY] indicating bimolecular termination. The values of kp2/kt and energy of activation have been computed as 6.3 × 10−3 l mol−1s−1 and 63 KJ mol l−1, respectively. The reactivity ratios have been calculated as r1 (MMA) = .60, r2 (Sty) = .35, by using the Kelen-Tudös method. The copolymerization reaction is initiated by the phenyl free radical. The formation of phenyl radicals may be attributed to the pp-dp overlap between the hybridized sp2 orbital and the larger and more diffuse 4d orbital of arsenic.

Radical polymerization of vinyl acetate using p-acetylbenzylidene triphenylarsonium ylide as an initiator

p-Acetylbenzylidene triphenylarsonium ylide initiated radical polymerization of vinyl acetate in dioxane has been carried out at 65±0.1°C in polymerization tubes for 8 h under nitrogen. The initiator and monomer exponents are 0.44 and 1.5 respectively. The overall activation energy and value of k 2 p/ k t are 35 kJ mol −1 and 6.06×10 −3 l mol −1 s −1 respectively. The ylide is believed to dissociate to generate phenyl radicals which initiate the radical polymerization of vinyl acetate.

Kinetics and mechanism of radical polymerization of methylmethacrylate using p-acetylbenzylidene triphenylarsonium ylide (p-ABTAY) as an initiator

Solution polymerization of methylmethacrylate (MMA) initiated by p-acetylbenzylidene triphenylarsonium ylide in dioxane was carried out at 60±0.2 °C up to 10 hrs. in a polymerization tube under a nitrogen atmosphere. The values of the initiator and the monomer exponent were computed as 0.46 and 1.03, respectively. The overall activation energy and kp2/kt were calculated as 53 KJ/mole and 1.19 × 10−2 L/mol·s, respectively for the polymerization.

Synthesis of arsenic containing polymethylmethacrylate using p-acetyl benzylidene triphenyl arsonium ylide as photoinitiator

Arsenic containing syndiotactic polymethylmethacrylate (PMMA) using p-ABTAY (p-acetyl benzylidene triphenyl arsonium ylide)in benzene as the photoinitiator at 30 ± 0.2°C has been synthesized. The system follows non-ideal kinetics ( R p ∝ [ I] 0.25 [M]) due to both primary radical termination and degradative chain transfer reaction. The glass transition temperature of PMMA is 145°C. Analysis of the polymer by SEM technique shows the presence of arsenic in it. The polymer has been characterized by Infra-red spectroscopy.

P-Acetyl Benzylidene Triphenylarsonium Ylide Initiated Radical Terpolymerization of Styrene, Acrylonitrile and Copper Acrylate: Synthesis, Characterization and Properties

Solution terpolymerization of styrene (Sty), acrylonitrile (AN) and copper acrylate (CuA) has been carried out in dimethylformamide at 90°C for 4 h using p-acetyl benzylidene triphenylarsonium ylide as radical initiator. 1 H nuclear magnetic resonance (NMR), IR and elemental analysis have been used to characterize the terpolymer. Analysis of kinetic data indicates the following rate equation : R p ∞ [ylide] 0.5 [Sty][AN] 1/[CuA] The overall activation energy is 38 kJ mol -1 . The composition of terpolymer calculated from NMR and elemental analysis has been used to evaluate reactivity ratios as r 1 (Sty) = 5 ± 2 and r 2 (AN + CuA) = 0.4 ± 0.02 employing the Finemann-Ross method, which confirms its random origin. The terpolymer was thermally stable up to 200°C.

P-Acetyl Benzylidene Triphenylarsonium Ylide Initiated Radical Terpolymerization of Styrene, Acrylonitrile and Copper Acrylate: Synthesis, Characterization and Properties

p-Acetyl Benzylidene Triphenylarsonium Ylide Initiated Radical Terpolymerization of Styrene, Acrylonitrile and Copper Acrylate: Synthesis, Characterization and Properties

Radical polymerization of styrene initiated by p-acetyl benzylidene triphenylarsonium ylide

The kinetics of the polymerization of styrene in bulk and in dilute systems in the presence of p-acetyl benzylidene triphenylarsonium ylide ( p-ABTAY) as radical initiator has been examined at 60 ± 0.1°C for 20 h under N 2. The values of the initiator exponent and the monomer exponent showed that the system follows ideal radical kinetics with bimolecular termination. The overall activation energy and average value of k 2 p k t are 64.6 kJ mol −1 and 0.10 × 10 −2 l mol −1 s −1, respectively. The ylide dissociates to produce phenyl radical, which brings about polymerization.

Mechanistic and kinetic studies of the polymerization of styrene photoinitiated by p-acetyl benzylidene triphenylarsonium ylide

The bulk polymerization of styrene, photoinitiated by p-acetyl benzylidene triphenylarsonium ylide ( p-ABTAY), at 35 ± 0.1 °C for 75 min was investigated. A free radical mechanism with bimolecular termination was confirmed from the study of the kinetics and the inhibiting effect of hydroquinone. From the analysis of the photodecomposition products, it is suggested that the phenyl radical, generated from the bond fission between the arsenic atom and the phenyl group, participates in the initiation of the free radical polymerization. The overall energy of activation Δ E is 41.9 kJ mol −1 and k 2 p k t = 0.466 × 10 −3 l mol −1 s −1.