Benzoyl peroxide–p‐acetylbenzylidenetriphenyl arsoniumylide initiated copolymerization of citronellol and styrene

Alternating copolymers, containing styrene and citronellol sequences, have been synthesized by radical polymerization using benzoylperoxide (BPO)–p‐acetylbenzylidenetriphenyl arsoniumylide (pABTAY) as initiator, in xylene at 80 ± 1 °C for 3 h under inert atmosphere. The kinetic expression is R_p ∝ [BPO]^0.88 [citronellol]^0.68 [styrene]^0.56 with BPO and R_p ∝ [pABTAY]^0.27 [citronellol]^0.76 [styrene]^0.63 with pABTAY, ie the system follows non‐ideal kinetics in both cases, because of primary radical termination and degradative chain transfer reactions. The activation energy with BPO and pABTAY is 94 kJ mol^?1 and 134 kJ mol^?1, respectively. Different spectral techniques, such as IR, FTIR, ¹H NMR and ¹³C NMR, have been used to characterize the copolymer, demonstrating the presence of alcoholic and phenyl groups of citronellol and styrene. The alternating nature of the copolymer is shown by the product of reactivity ratios r₁ (Sty) = 0.81 and r₂ (Citro) = 0.015 using BPO and r₁ (Sty) = 0.37 and r₂ (Citro) = 0.01 using (pABTAY), which are calculated by the Finemann–Ross method. A mechanism of copolymerization is proposed. © 2001 Society of Chemical Industry     

Polymerization of methyl methacrylate with Ni(acac)2–methylaluminoxane catalyst

Polymerization of methyl methacrylate (MMA) with nickel(II) acetylacetonate [Ni(acac)₂] in combination with methylaluminoxane (MAO) was investigated. Ni(acac)₂ was found to be an effective catalyst for the polymerization of MMA. From a kinetic study of the polymerization of MMA with the Ni(acac)₂–MAO catalyst, the overall activation energy was estimated to be 15 kJmol⁻¹. The polymerization rate (R_p) was expressed as follows: R_p = k [MMA]^1.0[Ni(acac)₂–MAO]^0.6 (the MAO/Ni mole ratio was kept constant). The mechanism for the polymerization of vinyl monomers with the Ni(acac)₂–MAO catalyst is discussed. © 2000 Society of Chemical Industry     

Synthesis and characterization of copolymer of styrene with methacrylic acid initiated by triphenylbismuthonium 1,2,3,4‐ tetraphenylcyclopentadienylide

The radical copolymerization of styrene with methacrylic acid (MAA) initiated by triphenylbismuthonium 1,2,3,4‐tetraphenylcyclopentadienylide in dioxan at 80 ± 0.1 °C for 3 h results in the formation of alternating copolymer as evidenced from the values of reactivity ratios as r₁ (styrene) = 0.03 and r₂ (MAA) = 0.025. The kinetic expression is R_p α [I]^0.5 [Sty] [MAA] and overall energy of activation is computed to be 23 kJ/mol. The FTIR spectrum of the copolymer shows the presence of bands at 3054 cm^?1 assigned to the phenyl group of styrene and at 1724 cm^?1 assigned to the ? COOH group of MAA. The ¹H‐NMR spectrum of the copolymer shows peaks between 7.20 and 7.27 δ assigned to the phenyl protons of styrene and at 12.5 δ assigned to the COOH proton of MAA. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1838–1843, 2005     

Synthesis and Characterization of Methylmethacrylate-alt-N-vinyl-2-pyrrolidone Initiated by Phosphorus Containing 1,2 Dipolar Compound

Copolymerization of methylmethacrylate (MMA) with 1-vinyl-2-pyrrolidone (N-VP), initiated by p-nitrobenzyl triphenyl phosphonium ylide in dioxane at 60°C for 60 min under inert atmosphere of nitrogen yields alternating copolymer as evidenced by the values of r ₁ = 0.01 and r ₂ = 0.02. The kinetic expression was R_p ∝ [I]^0.75[MMA]^1.2[VP]^1.2. The overall activation energy is 45.4 kJ/mol. The FTIR bands of OCH₃ of MMA at 1725 cm^?1 and –C=O of N-VP at 1679 cm^?1, confirms the incorporation of both the monomers in the copolymer. The glass transition temperature of the copolymer is 133°C. The GPC data shows the polydispersity index at about 1.5. The ESR spectroscopy confirm phenyl radical responsible for initiation.     

Effect of LiClO4 on radical polymerization of methyl methacrylate

The effect of LiClO₄ on the polymerization of methyl methacrylate (MMA) with dimethyl 2,2′-azobisisobutyrate (MAIB) was investigated at 50°C in methyl ethyl ketone. The polymerization proceeded homogeneously even at [LiClO₄] as high as 3.00 mol/L. The polymerization rate (R_p) and the molecular weight of the resulting polymer profoundly increased with increasing [LiClO₄]. R_p at 3.00 mol/L [LiClO₄] was 12 times that in the absence of LiClO₄. The rate equation depended on the presence or absence of LiClO₄: R_p = k′[MAIB]^0.5 [MMA]^1.5 in the presence of 3.00 mol/L [LiClO₄] and R_p = k[MAIB]^0.5 [MMA]^1.0 in the absence of LiClO₄. The overall activation energies of polymerization were 38.5 kJ/mol in the presence of 3.00 mol/L [LiClO₄] and 77.4 kJ/mol in the absence of LiClO₄, respectively. The tacticities of resulting poly(MMA) were insensitive to the presence of LiClO₄. In the copolymerization of MMA and styrene, Q and e values of MMA increased with increasing [LiClO₄], leading to enhanced alternating copolymerizability. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1361–1368, 1997     

Synthesis and characterization of functional copolymer of Linalool and vinyl acetate: A kinetic study

Linalool (LIN) and vinyl acetate (VA) were copolymerized by benzoyl peroxide (BPO) in p‐xylene at 60°C for 90 min. The system follows nonideal kinetics: R_pα[I]^0.6[LIN]^1.2[VA]^1.1. It results in the formation of alternating copolymer as evidenced from reactivity ratios as r₁ (VA) = 0.01, r₂ (LIN) = 0.0015, which have been calculated by Kelen–Tudos method. The overall activation energy is 82 kJ/mol. The FTIR spectrum of the copolymer shows the presence of the band at 3425 cm^?1 due to alcoholic group of LIN and at 1641 cm^?1 due to >C?O group of VA. The ¹H‐NMR spectrum shows peaks at 7.0–7.7 δ due to hydroxy proton of LIN and at 1.0–1.4 δ due to acetoxy protons of VA. ¹³C‐NMR spectrum of copolymer shows peaks at 167 ppm due to acetoxy group and at 75–77 ppm due to C? OH group. The Alfrey–Price Q–e parameters for LIN has been calculated as Q₂ = 1.24 and e₂ = 3.11. The copolymer is highly thermally stable and has a glass transition temperature (T_g) of 85°C, evaluated from DSC studies. The mechanism of copolymerization has been elucidated. This article also reports measurement of Mark–Houwink constants in THF at 25°C by means of GPC as α = 0.8 and K = 3.0 × 10^?4 dl/g. The thermal decompositions of copolymer are established with the help of TGA technique. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1134–1143, 2004     

Copolymerization of n‐butylacrylate with styrene by a novel photoinitiator, 1‐(bromoacetyl)pyrene

A comparative study on photoinitiated solution copolymerization of n‐butylacrylate (BA) with styrene (Sty) using pyrene (Py), 1‐acetylpyrene (AP), and 1‐(bromoacetyl)pyrene (BP) as initiators showed that the introduction of a chromophoric moiety, bromoacetyl (? COCH₂Br), significantly increased the photoinitiating ability of pyrene. The kinetics and mechanism of copolymerization of BA with Sty using BP as photoinitiator have been studied in detail. The system follows nonideal kinetics (R_p ∝ [BP]^0.34 [BA]^1.07 [Sty]^0.97). The nonideality was attributed to both primary radical termination and degradative initiator transfer. The monomer reactivity ratios of Sty and BA have been estimated by the Finemann–Ross and Kelen–Tudos methods, by analyzing copolymer compositions determined by ¹H NMR spectra. The values of r₁ (Sty) and r₂ (BA) were found to be 0.78 and 0.25, respectively, which suggested the high concentration of alternating sequences in the random copolymers obtained. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3233–3239, 2006     

Functional copolymer of geraniol and acrylonitrile: Synthesis and characterization

The radical copolymerization of acyclic terpene namely geraniol [GER] with acrylonitrile [AN] in DMF at (70 ± 0.1)°C for 1 h, using benzoylperoxide (BPO) as an initiator has been carried out under inert atmosphere of nitrogen. The kinetic expression for reaction is R_p ∝ [BPO]^0.5 [AN]^1.0 [GER]^1.0. The IR spectrum of the copolymer shows bands at 3432 and at 2244 cm^?1 due to ? OH group of GER and ? CN group of AN, respectively. The ¹³C‐NMR spectrum shows peaks at 73–75 δ ppm and 116–120 δ ppm due to ? OH group of GER and ? CN group of AN, respectively. The thermogravimetric analysis and differential scanning calorimetry study shows that copolymer is thermally stable up to 407°C and has glass transition temperatures (T_g) 56°C. The reactivity ratios r₁ (AN) and r₂ (GER) have been calculated as 0.05 and 0.005, respectively. The Alfrey‐Price Q‐e parameter for GER has been calculated as 0.094 and ?2.0, respectively. The molecular weights of the copolymers have been evaluated by gel‐permeation chromatography. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Formation of poly(methyl methacrylate) with novel solubility characters in the photopolymerization with bis(cyclopentadienyl)titanium dichloride in a water–methanol mixture

Methyl methacrylate (MMA) was observed to be easily polymerized in the photopolymerization with bis(cyclopentadienyl)titanium dichloride (Cp₂TiCl₂) in a water–methanol mixture under irradiation of a 15-W fluorescent room lamp. The polymerization proceeded heterogeneously. The rate (R_p) of heterogeneous photopolymerization in a 1 : 1 (v/v) water–methanol mixture at 40°C was apparently given by R_p=k[Cp₂TiCl₂]^0.2 [MMA]^2.4. The resulting poly(MMA) was found to contain a tetrahydrofuran (THF)-insoluble part. The separated THF-insoluble part differed significantly from the usual radical poly(MMA) in solubility characters. It is of great interest that the THF-insoluble poly(MMA) was soluble in benzene and toluene, but insoluble in polar solvents, such as ethyl acetate, acetone, methyl ethyl ketone, dimethylformamide, and dimethylsulfoxide. The copolymerization results of MMA and acrylonitrile revealed that the present photopolymerization initiated with Cp₂TiCl₂ proceeds via a radical mechanism. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 525–531, 1998     

1‐(bromoacetyl)pyrene and its arsonium salt as novel photoinitiators for styrene polymerization

The photopolymerization of styrene (Sty) in DMSO induced by pyrene (Py), 1‐Acetylpyrene (AP), 1‐(Bromoacetyl) pyrene (BP), and 1‐Acetylpyrene triphenyl arsonium bromide (APAS) has been investigated. Under all conditions employed, Py was completely ineffective. Incorporation of a chromophoric (? COCH₃) moiety introduces photoinitiating activity into Py. It was observed that introduction of Br into AP markedly accelerated the rate of UV irradiation‐induced polymerization. BP was further modified to its arsonium salt (APAS). The kinetics and mechanism of polymerization using BP and APAS as initiators have been investigated in detail. The polymerization with BP followed nonideal kinetics (R_p ∝ [BP]^0.8 [Sty]^1.1) with respect to initiator concentration whereas ideal kinetics (R_p ∝ [APAS]^0.48 [Sty]^1.1) was observed when APAS was used as initiator. Degradative transfer is thought to be mainly responsible for this unusual kinetic behavior for BP–Sty system. The kinetic data proved that BP was more effective and faster initiator than APAS. In both the cases, the mechanism of polymerization was free radical as evident by inhibiting the effect of hydroquinone and ESR studies. IR and NMR spectra showed the atactic nature of polystyrene. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1793–1798, 2006     

Synthesis of substituted polymethylenes from acenaphthylene by radical polymerization and copolymerization

Radical polymerization of acenaphthylene (Ace) as a 1,2-disubstituted ethylene was investigated. It was found that the polymerization rate (R_p) was expressed as follows: R_p = k[Ace]^1.0[AIBN]^0.68, and that the overall activation energy was 113 kJ/mol for polymerization with 2,2'-azobisisobutyronitrile (AIBN) in benzene at 50–70°C. Poly(Ace) obtained was characterized by NMR spectroscopy and GPC. Some substituted copolymethylenes were also prepared by radical copolymerization of Ace with other 1,2-disubstituted ethylenes, that is, maleic anhydride, diisopropyl fumarate, and N-cyclohexylmaleimide. The monomer reactivity ratios were determined from comonomer–copolymer composition curves.     

Kinetics of ylide-initiated radical copolymerization of 4-vinylpyridine and methyl methacrylate

The ylide-initiated radical copolymerization of 4-vinylpyridine (4-VP) with methyl methacrylate (MMA) at 60°C using carbon tetrachloride as inert solvent yields non-alternating copolymers. The kinetic parameters, average rate of polymerization (R_p) and orders of reaction with respect to monomers and initiator, have been evaluated and the kinetic equation is found to be R_pα[ylide]^0.94 [MMA]^1.0 [4-VP]^1.5. The values of the energy of activation and k_p²/k_t are 48 kJ mol^?1 and 6.6 × 10^?5 litre mol^?1s^?1, respectively. The copolymers have been characterized by IR and NMR spectroscopy.     

Kinetic study of the polymerization of dimethyldiallylammonium chloride and acrylamide

The kinetics of the polymerization of dimethyldiallylammonium chloride (DMDAAC) and acrylamide (AM) with different monomer molar ratios initiated by an ammonium persulfate–sodium bisulfate redox complex in an aqueous solution were studied. The polymerization rate (R_p) equation, the activation energy (E_a), and the reactivity ratio were measured. The results show that when the n_DMDAAC:n_AM values were 1 : 9, 2 : 8, 3 : 7, 4 : 6, and 5 : 5, the copolymerization rate equation were R_p1 = k[M]^2.61[I_O]^0.51[I_R]^0.52, R_p2 = k[M]^2.70[I_O]^0.50[I_R]^0.53, R_p3 = k[M]^2.73[I_O]^0.50[I_R]^0.56, R_p4 = k[M]^2.77[I_O]^0.51[I_R]^0.59, and R_p5 = k[M]^2.84[I_O]^0.51[I_R]^0.61 (where [M] is the total monomer concentration, [I_O] is the oxidant concentration, and [I_R] is the reductant concentration), respectively when the temperature was 45°C. The E_a values were E_a1 = 79.10 kJ/mol, E_a2 = 81.39 kJ/mol, E_a3 = 85.15 kJ/mol, E_a4 = 88.88 kJ/mol, and E_a5 = 90.61 kJ/mol in the temperature range 35–55°C, respectively. The reactivity ratios of DMDAAC and AM were r_DMDAAC = 0.14 and r_AM = 6.11 when the temperature was 45°C. The structure of PDA was characterized by Fourier transform infrared spectroscopy and ¹H-NMR. The results of the kinetic parameters explained the differences in the copolymerization rate and intrinsic viscosity of PDA with different cationicities. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

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 (R_p ∝ [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 k_p²/k_t 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     

Photochemical-induced polymerization kinetics of styrene and methyl methacrylate by initiation of binary system composed of polyethylene oxide with aniline end group and benzophenone

The kinetics of photochemical polymerization of styrene (St) and methyl methacrylate (MMA) using a binary initiation system composed of poly(ethylene oxide) with an aniline end group (PEO_a) and benzophenone (BP) was investigated by a modified dilatometer. The effect of the concentration of the monomer, BP and PEO_a, and of the molecular weight of PEO_a on the polymerization rate (R_p) and conversion of monomers is discussed in detail. The formulas of R_p ∝︁ [PEO_a]^0.38 [St]^0.33 [BP]^0.56 and R_p ∝︁ [PEO_a]^0.36 [MMA]^0.30 [BP]^0.54 using benzene as a solvent are derived when the molecular weight of PEO is 11,000 (PEO_a — 11,000). Compared with the small aminophenol (AP), there existed a critical PEO_a concentration to affect the R_p and conversion of the monomers and the critical concentration is strongly dependent on the polarity of the solvents and molecular weight of PEO_a. It is confirmed that in the same conditions the solution polymerization behavior of St and MMA initiated by the imino radical of PEO would not be affected by the properties of the second block although PMMA is miscible and PS is immiscible with PEO_a in the bulk. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2095–2103, 1997     

Kinetic and mechanistic studies on the block copolymerization of methyl methacrylate initiated by Ce4+-poly (ethylene glycol) redox system

The kinetic and mechanistic features of tetravalent cerium-poly(ethylene glycol) (PEG, molecular weight 6000) redox couple initiated block copolymerization of methyl methacrylate (MMA) have been investigated in aqueous acidic medium in the temperature range 30–50°C. The block copolymerization behavior as a function of [Ce⁴⁺], [PEG], [MMA], [H⁺], [NO₃⁻], as well as temperature, have been studied. The overall rate of polymerization (R_p), the rate of disappearance of Ce⁴⁺ (R_Ce), and the number average molecular weight (M _n) have been determined from gravimetry, cerimetry, and gel permeation chromatography, respectively. R_p has been found to bear a square dependence on [MMA] and independent of both [Ce⁴⁺] and [H⁺]. R_Ce has been found to be directly proportional to [Ce⁴⁺] and [H⁺], and independent of [MMA]. Both R_p and R_Ce have been found to be retarded on adding nitrate ions, while increase of temperature accelerated the rates. The M _n of the block copolymer has been found to depend on [Ce⁴⁺], [PEG], [MMA], and [H⁺] as well as on temperature. A plausible reaction scheme has been derived and suitable kinetic expressions have been evaluated based on these observations. It has been concluded that by varying the temperature and concentration of the components of the redox system, it is possible to control the rate of polymerization and the molecular weight of the resulting block copolymer. © 1997 John Wiley & Sons, Inc.     

Kinetics of graft copolymerization of methyl methacrylate in wool fibers

The graft copolymerization of methyl methacrylate in wool fibers was investigated in the aqueous LiBr–K₂S₂O₈ system without homopolymer. The rate of grafting and the degree of polymerization of graft polymer were determined on varying the extent of reduction of wool fibers and the concentration of monomer. From the graft copolymerization behavior observed at a given concentration of redox catalysts (LiBr and K₂S₂O₈), the thiol groups in wool fibers were considered to play a role as a sort of catalyst of polymerization, not as the chain transfer agent, and also to give the grafting sites. So, the initiation process of grafting was assumed to be started by d[S·]/dt = k_i[SH]_eff, and the kinetic consideration was found to lead to the following expression in agreement with the experimental results: 1/DP = (k_t/k_p²[M]_fib²)R_p, where d[S·]/dt is the rate of formation of thiol radicals by radicalotropy to ? SH from SO₄^?., OH·, or Br·; k_i, k_p, and k_t are the rate constants of initiation, propagation, and termination, respectively; [SH]_eff and [M]_fib are the concentration of the effective thiol groups and the MMA monomers within the wool fibers, respectively; DP is the average degree of polymerization of graft polymers, and R_p the overall rate of grafting.     

Preparation of soap‐free cationic emulsion using polymerizable surfactant

A kind of polymerizable surfactant, methacryloyloxyethylhexadecyldimethylammonium bromide (DMHB) was used to synthesis soap‐free cationic emulsion with styrene (St), methyl methacrylate (MMA), and methacryloyloxyethyltrimethylammonium chloride (MATMAC) by emulsion polymerization using 2,2′‐azobis(isobutylamidine hydrochloride) (AIBA) as a cationic initiator. The effects of polymerizable surfactant concentration, initiator concentration, and reaction temperature on the conversion of monomer were investigated. The results indicated that the rate of polymerization could be expressed as R_p = k_p[AIBA]^0.42[DMHB]^0.45 and the apparent activation energy (E_a) was 83.42 kJ/mol. The particle size, ζ potential, and apparent charge density of cationic latices were also measured. The average diameter of copolymer particles decreased with increasing DMHB, MATMAC, and AIBA content; the charge properties of the particles were decided by the DMHB, MATMAC, and AIBA content. The polymerization mechanism is discussed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1111–1116, 2006     

Kinetics for chlorination of maleic anhydride grafted polypropylene

Preparation of Chlorinated maleic anhydride grafted polypropylene (Cl‐PP‐g‐MAH) by free radical process was carried out using carbon tetrachloride (CCl₄) as the solvent and benzoperoxide (BPO) as the initiator. Effects of reaction temperature, concentrations of PP‐g‐MAH and BPO on the rate of chlorination were studied. The experimental results showed the actual rate constant for chlorination of maleic anhydride grafted polypropylene followed the Arrhenius law and the total apparent activation energy was 19.7 kJ mol^?1. The kinetic model for chlorination of maleic anhydride grafted polypropylene was found to be R = K[BPO]^0.53[C]^0.93. The properties of chlorination of maleic anhydride grafted polypropylene were better than those of maleic anhydride grafted polypropylene. The products were characterized by Fourier transform infrared spectroscopy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Copolymerization and thermal behavior of methyl methacrylate with N‐(phenyl/p‐tolyl) itaconimides

This study describes the synthesis, characterization, and thermal behavior of copolymers of methyl methacrylate (MMA) and N‐p‐tolyl itaconimide (PTI)/N‐phenyl itaconimide (I). Homopolymerization and copolymerization of N‐(phenyl/p‐tolyl) itaconimide with MMA was carried out by use of various mole fractions of N‐aryl itaconimide in the initial feed from 0.1 to 0.5, using azobisisobutyronitrile as an initiator and tetrahydrofuran as the solvent. The copolymer composition was determined by ¹H‐NMR spectroscopy using the proton resonance signals attributed to –OCH₃ of MMA (δ = 3.5–3.8 ppm) and the aromatic protons (δ = 7.0–7.5 ppm) of N‐aryl itaconimide. The reactivity ratios of the monomers were found to be r₁ (PTI) = 1.33 ± 0.05/r₂ (MMA) = 0.24 ± 0.03 and r₁ (I) = 1.465 ± 0.035/r₂ (MMA) = 0.385 ± 0.005. The molecular weight of the copolymers decreased with increasing mole fraction of N‐aryl itaconimide in the copolymers. Glass‐transition temperature (T_g) and thermal stability of PMMA increased with increasing amounts of itaconimides in the polymer backbone. A significant increase in the percentage char yield at 700°C was observed on incorporation of a low mole fraction of N‐aryl itaconimides. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1195–1202, 2003