Overall Activation Energy Of Polymerization Research Articles

Synthesis, characterization polymerization and antibacterial properties of novel thiophene substituted acrylamide

Ethyl 2-acrylamido-4,5,6,7-tetrahydrobenzo [b] thiophene-3-carboxylate (ETTCA) has been synthesized and its structure has been elucidated by elemental analysis and spectral tools. Free radical polymerization of (ETTCA) has been conducted in several solvents using azobisisobutyronitrile (AIBN) as an initiator. The kinetic parameters of polymerization of the ETTCA were investigated, and it was found that the polymerization reaction follows the conventional free radical scheme. The overall activation energy of polymerization Δ E was determined (Δ E = 45.11 kJ mol −1). The copolymerization of ETTCA with three conventional monomers was carried out in dioxane at 65 °C. The monomer reactivity ratios for the copolymerization of ETTCA with methyl methacrylate (MMA), vinyl acetate (VA) and vinyl ether (VE) were calculated. Thermal stability of the ETTCA polymer and its copolymers were investigated by thermogravimetric analysis. It has been found that the prepared polymer (PETTCA) and its copolymers with VA have moderate biological activity and highly dependent on the copolymer composition.

Polymerization of 1,3‐dienes containing functional groups: 8. Free‐radical polymerization of 2‐triethoxysilyl‐ 1,3‐butadiene

AbstractThe presence of a bulky substituent at the 2‐position of 1,3‐butadiene derivatives is known to affect the polymerization behavior and microstructure of the resulting polymers. Free‐radical polymerization of 2‐triethoxysilyl‐1,3‐butadiene (1) was carried out under various conditions, and its polymerization behavior was compared with that of 2‐triethoxymethyl‐ and other silyl‐substituted butadienes. A sticky polymer of high 1,4‐structure ($E:Z \approx 8:2$) was obtained in moderate yield by 2,2′‐azobisisobutyronitrile (AIBN)‐initiated polymerization. A smaller amount of Diels–Alder dimer was formed compared with the case of other silyl‐substituted butadienes. The rate of polymerization (Rp) was found to be Rp = k[AIBN]0.5[1]1.2, and the overall activation energy for polymerization was determined to be 117 kJ mol−1. The monomer reactivity ratios in copolymerization with styrene were r1 = 2.65 and rst = 0.26. The glass transition temperature of the polymer of 1 was found to be −78 °C. Free‐radical polymerization of 1 proceeded smoothly to give the corresponding 1,4‐polydiene. The 1,4‐E content of the polymer was less compared with that of poly(2‐triethoxymethyl‐1,3‐butadiene) and poly(2‐triisopropoxysilyl‐1,3‐butadiene) prepared under similar conditions. Copyright © 2010 Society of Chemical Industry

Polymerization of 1,3‐dienes with functional groups. III. Free‐radical polymerization of N,N‐diethyl‐2‐methylene‐3‐butenamide

AbstractFree‐radical homo‐ and copolymerization behavior of N,N‐diethyl‐2‐methylene‐3‐butenamide (DEA) was investigated. When the monomer was heated in bulk at 60 °C for 25 h without initiator, rubbery, solid gel was formed by the thermal polymerization. No such reaction was observed when the polymerization was carried out in 2 mol/L of benzene solution with with 1 mol % of azobisisobutyronitrile (AIBN) as an initiator. The polymerization rate (Rp) equation was Rp ∝ [DEA]1.1[AIBN]0.51, and the overall activation energy of polymerization was calculated 84.1 kJ/mol. The microstructure of the resulting polymer was exclusively a 1,4‐structure where both 1,4‐E and 1,4‐Z structures were included. From the product analysis of the telomerization with tert‐butylmercaptan as a telogen, the modes of monomer addition were estimated to be both 1,4‐ and 4,1‐addition. The copolymerizations of this monomer with styrene and/or chloroprene as comonomers were also carried out in benzene solution at 60 °C. In the copolymerization with styrene, the monomer reactivity ratios obtained were r1 = 5.83 and r2 = 0.05, and the Q and e values were Q = 8.4 and e = 0.33, respectively. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 999–1007, 2004

A new method to measure the conversion of radiation polymerization of electrolyte monomer diallyldimethylammonium chloride in dilute aqueous solution

The dependence of electrical conductivity on concentrations of diallyldimethylammonium chloride (DADMAC) monomer, linear poly(DADMAC) and their mixture monomer/poly(DADMAC) in dilute aqueous solution exhibits a linear relationship. It was possible to calculate conversion of DADMAC polymerization by measuring its electric conductivity. Although the electrical conductivity of the poly(DADMAC) solution decreased with increasing its molecular weight, in the process of UV or ionizing radiation polymerization the molecular weight of the polymers could be kept constant in the case of fixed temperature, UV-luminous intensity or dose rate. Based on the method mentioned above, the kinetics of UV induced polymerization of DADMAC in aqueous solution was studied; the overall activation energy of polymerization of DADMAC in the water phase was calculated to be 18.8 kJ mol−1. γ?-Radiation-induced polymerization of DADMAC in aqueous solution as a function of absorbed dose was studied as well. The conversion of DADMAC increased quickly with dose before 30 kGy and then increased slowly. The experimental data of both UV- and γ-induced polymerization were verified to be reliable by inverted ultracentrifugation method.

Polymerization of 1,3‐dienes with functional groups. II. Free‐radical polymerization of N‐(2‐methylene‐3‐butenoyl)piperidine

AbstractThe free‐radical homopolymerization and copolymerization behavior of N‐(2‐methylene‐3‐butenoyl)piperidine was investigated. When the monomer was heated in bulk at 60 °C for 25 h without an initiator, about 30% of the monomer was consumed by the thermal polymerization and the Diels–Alder reaction. No such side reaction was observed when the polymerization was carried out in a benzene solution with 1 mol % 2,2′‐azobisisobutylonitrile (AIBN) as an initiator. The polymerization rate equation was found to be Rp ∝ [AIBN]0.507[M]1.04, and the overall activation energy of polymerization was calculated to be 89.5 kJ/mol. The microstructure of the resulting polymer was exclusively a 1,4‐structure that included both 1,4‐E and 1,4‐Z configurations. The copolymerizations of this monomer with styrene and/or chloroprene as comonomers were carried out in benzene solutions at 60 °C with AIBN as an initiator. In the copolymerization with styrene, the monomer reactivity ratios were r1 = 6.10 and r2 = 0.03, and the Q and e values were calculated to be 10.8 and 0.45, respectively. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1545–1552, 2003

Indenyl-amido titanium and zirconium dimethyl complexes: improved synthesis and use in propylene polymerization

The synthesis of a series of indenyl amido titanium dimethyl complexes, by means of the direct synthesis from the ligand, a 2-fold excess of MeLi, and TiCl 4 is reported. The 1H NMR spectra of the complexes show a quartet structure for the metal-bound methyl groups, due to through-metal proton–proton coupling. Coupling of Ti-methyl protons with protons on the Cp ring is also revealed by COSY 2D-NMR. The performance of the Ti complexes in propylene polymerization, including [Me 2Si(Me 4C 5)( t-BuN)]TiMe 2 ( 1-TiMe 2 ), [Me 2Si(Ind)( t-BuN)]TiMe 2 ( 2-TiMe 2 ) and six other methyl titanium complexes bearing substituted indenyl ligands, has been investigated with different cocatalysts and at different polymerization temperatures and propylene concentrations. All complexes produce amorphous polypropylene ( am-PP). The catalytic activity and molecular weight strongly depend on the substitution of the Cp ring: 2-TiMe 2 gives polymers of lower molecular weight, while the presence of a methyl group in position 2 (as in 3-TiMe 2 ) determines up to 4-fold increase in molecular weight. The type of cocatalyst influences mainly the catalytic activity, the borates being better activators than MAO, but also molecular weight, with again the borates giving higher molecular weights than MAO. 5-TiMe 2 –Ph 3CB(C 6F 5) 4 shows an overall activation energy of polymerization of 7.35 kcal mol −1. The rate of chain release is first order in monomer. The following activation energies for overall chain release have been calculated: ΔΔ E ‡ 2-TiMe 2 =3.4 kcal mol −1, ΔΔE ‡ 5-TiMe 2 =3.8 kcal mol −1, ΔΔ E ‡ 3-TiMe 2 =6.3 kcal mol −1. Even if all the polymers produced are amorphous, 2-TiMe 2 and 5-TiMe 2 show a microstructure unbalanced towards isotacticity, while 3-TiMe 2 , 6-TiMe 2 and 8-TiMe 2 are syndiotactic-enriched. Chiral induction comes mainly from a weak enantiomorphic site control.

Polymerization of acrylonitrile catalyzed by single yttrium tris(2,6‐di‐tert‐butyl‐4‐methyl phenolate)

AbstractPolymerization of acrylonitrile was carried out using yttrium tris(2,6‐di‐tert‐butyl 4‐methyl‐phenolate) (Y(OAr)3) as single component catalyst for the first time. The effects of concentrations of the monomer and catalyst, kinds of rare earth element and solvent, as well as temperature and polymerization time were investigated. The overall activation energy of polymerization in n‐hexane and THF mixture is 18.3 kJ mol−1. Polyacrylonitriles (PANs) obtained by using Y(OAr)3 in n‐hexane and THF mixture at 50 °C are predominantly atactic, while yellow PANs obtained in DMF under the same conditions have a syndiotactic‐rich configuration (>50%), and their highly branched and/or cyclized structures have also been found.© 2002 Society of Chemical Industry

Winsor I-like (micro)emulsion polymerization of styrene initiated by oil-soluble initiator

Batch emulsion polymerization of styrene initiated by an oil-soluble initiator and stabilized by non-ionic emulsifier (Tween 20) has been investigated. The rate of polymerization vs. conversion curve shows the two non-stationary rate intervals typical for the non-stationary-state polymerization. This behavior is a result of the continuous particle nucleation and the decrease of monomer concentration at the reaction loci with increasing conversion. The initial increase of the polymerization rate is attributed to the increase of particle number and the polymerization proceeding under the monomer-saturated condition—the Winsor I-like (micro)emulsion polymerization. The decrease of the polymerization rate is the result of the depressed transfer of monomer from the monomer reservoir to the reaction loci. Above 50°C the monomer emulsion separates into two phases: the upper transparent monomer phase and the lower blue colored (microemulsion) phase. The polymerization mixture consists of the microdroplets (act as the reaction loci) and large degradable monomer droplets (act as the reservoir monomer and emulsifier). The continuous release of emulsifier from the monomer phase and the microdroplets induce the continuous particle nucleation up to high conversion. The initial formation of large particles results from the agglomeration of unstable growing particles and monomer droplets. The size of large (highly monomer-swollen) particles decreases with conversion and they merge with the growing particles at ca. 40–50% conversion. The coarse initial emulsion transformed during polymerization to the fine (semitransparent) polymer emulsion as a result of the continuous particle nucleation, the shrinking of highly monomer-swollen polymer particles and the depletion of monomer droplets. The low overall activation energy of polymerization is mainly ascribed to the decreased barrier for entering radicals into the latex particles with increasing temperature.

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 (Rp ) at 60 °C was expressed by Rp = k[MAIB]0.5±0.05[RS-MBEI]2.9±0.1. The rate constants of propagation (kp ) and termination (kt ) were determined by ESR. kp was very low, ranging from 0.3 to 0.8 L/mol s, and increased with the monomer concentration, whereas kt (4–17 × l04 L/mol s) decreased with the monomer concentration. Such behaviors of kp and kt were responsible for the high dependence of Rp on the monomer concentration. Rp depended considerably on the solvent used. S-MBEI, derived from (S)-α-methylbenzylamine, showed somewhat lower homopolymerizability than RS-MBEI. The kp 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

Polymerization of methyl methacrylate by single component catalyst of lanthanocene chloride O(C 2H 4C 5H 3CH 3) 2LnCl (Ln=Y, Nd, Sm)

A novel single component catalyst of lanthanocene chloride O(C 2H 4C 5H 3CH 3) 2LnCl (Ln=Y, Nd, Sm) was used to initiate the polymerization of methyl methacrylate (MMA) in bulk and in toluene solution system. The effects of temperature, time and molar ratio of MMA/Catalyst were studied in detail. The results showed that higher temperature and longer time were favorable for increasing the catalytic activities. Both polymerization conversion of MMA and molecular weight (MW) of PMMA formed in toluene are lower than those from bulk polymerization, which gives M w as high as 1.52×10 6, and MMA conversion more than 80%. The syndiotacticity of PMMA prepared at a temperature ranging from 20°C to 80°C is about 65%. GPC (gel permeation chromatography) shows that the MW distribution of PMMA obtained in bulk polymerization is as narrow as 1.3. Kinetic studies indicate that the polymerization rate is a first-order dependence on the concentration of MMA and catalyst, respectively. The overall activation energy of polymerization is 33.9 kJ/mol.

Kinetic and ESR studies on the radical polymerization of ?-n-(??-methylbenzyl) ?-ethyl itaconamates derived from racemic and (s)-?-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 (Rp ) at 60 °C was expressed by Rp = k[MAIB]0.5±0.05[RS-MBEI]2.9±0.1. The rate constants of propagation (kp ) and termination (kt ) were determined by ESR. kp was very low, ranging from 0.3 to 0.8 L/mol s, and increased with the monomer concentration, whereas kt (4–17 × l04 L/mol s) decreased with the monomer concentration. Such behaviors of kp and kt were responsible for the high dependence of Rp on the monomer concentration. Rp depended considerably on the solvent used. S-MBEI, derived from (S)-α-methylbenzylamine, showed somewhat lower homopolymerizability than RS-MBEI. The kp 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

Kinetic and ESR studies on radical polymerization of methyl methacrylate in the presence of fullerene

The effect of fullerene (C60) on the radical polymerization of methyl methacrylate (MMA) in benzene was studied kinetically and by means of ESR, where dimethyl 2,2′-azobis(isobutyrate) (MAIB) was used as initiator. The polymerization rate (Rp) and the molecular weight of resulting poly(MMA) decreased with increasing C60 concentration ((0–2.11) × 10−4 mol/L). The molecular weight of polymer tended to increase with time at higher C60 concentrations. Rp at 50°C in the presence of C60 (7.0 × 10−5 mol/L) was expressed by Rp = k[MAIB]0.5[MMA]1.25. The overall activation energy of polymerization at 7.0 × 10−5 mol/L of C60 concentration was calculated to be 23.2 kcal/mol. Persistent fullerene radicals were observed by ESR in the polymerization system. The concentration of fullerene radicals was found to increase linearly with time and then be saturated. The rate of fullerene radical formation increased with MAIB concentration. Thermal polymerization of styrene (St) in the presence of resulting poly(MMA) seemed to yield a starlike copolymer carrying poly(MMA) and poly(St) arms. The results (r1 = 0.53, r2 = 0.56) of copolymerization of MMA and St with MAIB at 60°C in the presence of C60 (7.15 × 10−5 mol/L) were similar to those (r1 = 0.46, r2 = 0.52) in the absence of C60. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2905–2912, 1998

Radical polymerization of ortho-(1,3-dioxolan-2-yl)phenyl ethyl fumarate involving intramolecular hydrogen abstraction and ring opening of cyclic acetal

The polymerization of o-(1,3-dioxolan-2-yl)phenyl ethyl fumarate (DOPEF) initiated with dimethyl 2,2 '-azobisiso-butyrate (MAIB) was studied kinetically in benzene. The polymerization rate (R p ) at 60°C was given by R p = k [MAIB] 0.76 [DOPEF] 0.71 . The overall activation energy of polymerization was calculated to be 98.3 kJ/mol. The number-average molecular weight of resulting poly(DOPEF) was in the range of 1000-3100. 'Hand 13 C-NMR spectra of resulting polymers revealed that the radical polymerization of DOPEF proceeds in a complicated manner involving vinyl addition, intramolecular hydrogen abstraction, and further ring opening of the cyclic acetal at higher temperatures. From the copolymerization of DOPEF (M 1 ) and styrene (St) (M 2 ) at 60°C, the monomer reactivity ratios were obtained to be r 1 = 0.02 and r 2 = 0.20, the values of which are similar to those of the copolymerization of ethyl o-formylphenyl fumarate and St.

Radical polymerization of benzylN-(2,6-dimethylphenyl)itaconamate

The polymerization of benzyl N-( 2,6-dimethylphenyl)itaconamate (BDMPI) with benzoyl peroxide (BPO) in N,N-dimethylformamide (DMF) was studied kinetically by ESR. The polymerization rate (R P ) at 70°C was given by R P = k[BPO] 0.78 [BDMPI] 11 . The overall activation energy of polymerization was determined to be 83.7 kJ/mol. The number-average molecular weight of poly( BDMPI) was in the range of 1500-2000 by gel permeation chromatography. From the ESR study, the polymerization system was found to involve ESR-observable propagating radicals of BDMPI under practical polymerization conditions. Using the polymer radical concentration by ESR, the rate constants of propagation (k P ) and termination (k t ) were determined in the temperature range of 50-70°C. The k P value seemed dependent on the chain-length of propagating radical. The analysis of polymers by the MALDI-TOF mass spectrometry suggested that most of the resulting polymers contain the dimethylamino terminal group. The copolymerization of BDMPI (M 1 ) and styrene (M 2 ) at 50°C in DMF gave the following copolymerization parameters; r 1 = 0.49, r 2 = 0.26, Q 1 = 1.2, and e 1 = +0.63. The thermal behavior of poly(BDMPI) was examined by dynamic thermogravimetry and differential scanning calorimetry.

Radical polymerization of benzyl N‐(2,6‐dimethylphenyl)itaconamate

The polymerization of benzyl N-(2,6-dimethylphenyl)itaconamate (BDMPI) with benzoyl peroxide (BPO) in N,N-dimethylformamide (DMF) was studied kinetically by ESR. The polymerization rate (Rp) at 70°C was given by Rp = k[BPO]0.78[BDMPI]1.1. The overall activation energy of polymerization was determined to be 83.7 kJ/mol. The number-average molecular weight of poly(BDMPI) was in the range of 1500–2000 by gel permeation chromatography. From the ESR study, the polymerization system was found to involve ESR-observable propagating radicals of BDMPI under practical polymerization conditions. Using the polymer radical concentration by ESR, the rate constants of propagation (kp) and termination (kt) were determined in the temperature range of 50–70°C. The kp value seemed dependent on the chain-length of propagating radical. The analysis of polymers by the MALDI-TOF mass spectrometry suggested that most of the resulting polymers contain the dimethylamino terminal group. The copolymerization of BDMPI (M1) and styrene (M2) at 50°C in DMF gave the following copolymerization parameters; r1 = 0.49, r2 = 0.26, Q1 = 1.2, and e1 = +0.63. The thermal behavior of poly(BDMPI) was examined by dynamic thermogravimetry and differential scanning calorimetry. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1891–1900, 1997

Kinetic study of acrylic acid solution polymerization

AbstractThe kinetics of acrylic acid (AA) solution polymerizations were characterized under various polymerization conditions using differential scanning calorimetry. The AA polymerization rate Rp decreased with increasing pH over all pH values due to the decreased reactivity of ionized AA relative to the unionized monomer. The rate behavior above pH 6 was suggestive of diffusion‐controlled termination kinetics. The degree of ionization thus impacted not only the reactivity of species in solution but also the diffusive characteristics of propagating macroradicals. As the AA concentration was increased, the change in polymerization rate with pH was substantially less. The temperature dependence of Rp indicated that the overall activation energy for polymerization varied with temperature, due to diffusion‐controlled termination kinetics. The polymerization rate was significantly higher when a multifunctional cross‐linking agent was added, because of the gel effect, even while maintaining a constant double bond concentration.

Polymerization of propylene using a prepolymerized high-active Ziegler-Natta catalyst. I. Kinetic studies

The kinetics of propylene polymerization using a prepolymerized high-active TiCl3 catalyst with an Et2AICI cocatalyst are investigated. The effect of various parameters such as AI/Ti ratio, pressure, temperature, hydrogen, and polymerization time on the rate of polymerization and yield are examined. The dependency of these parameters on the polymerization rate are studied. It is found that the variation at the rate of polymerization with the Et2AICI cocatalyst concentration complies with a Langmuir–Hinshelwood type of relationship. The overall activation energy of polymerization calculated from the Arrhenius plot was found to be 11.6 kcal/mol. © 1996 John Wiley & Sons, Inc.

Kinetics of cationic photopolymerizations of divinyl ethers characterized usingin situ Raman spectroscopy

In situ Raman spectroscopy experiments were used to determine effective kinetic propagation constants for a series of unsteady-state divinyl ether polymerizations at different isothermal temperatures and light intensities. Raman spectroscopy was found to be ideally suited for monitoring cationic photopolymerizations because the technique allows isothermal experiments to be performed with excellent time resolution and allows several spectral features to be observed simultaneously. In addition, the Raman experiments provided direct information about the vinyl bond concentration in situ as the reaction takes place. For these cationic photopolymerizations, the reaction rate and limiting conversion were both found to increase as the reaction temperature was increased. At all temperatures, the profile for the propagation rate constant, kp, exhibited a dramatic increase at the start of the reaction, plateaued at a value between 10 and 40 l/mol s (depending upon temperature), and then decreased as the reaction reached a limiting conversion due to trapping of the active centers. Finally, the overall activation energy for polymerization was found to be 25.1 ± 6.1 kJ/mol. © 1996 John Wiley & Sons, Inc.

Emulsion polymerization of butyl acrylate induced by sodium lauryl sulfate/hydroxymethane sulfinate

AbstractHydroxymethane sulfinate (sodium formaldehyde sulfoxylate, SFS) along with sodium lauryl sulfate (SLS) was used to induce the aqueous polymerization of n‐butyl acrylate (n‐BA). The reaction rate, molecular weights and latex stability with those two compounds were found to be promising. However, the polymerization involved a significantly limited conversion and broad dispersity in molecular weights and particle sizes. The polymerization behavior, depending on factors such as the concentrations of SFS, SLS and n‐BA was different from that of traditional emulsion polymerizations. The rate dependence on the reaction temperature was described well by the Arrhenius equation, and the overall activation energy of polymerization thus obtained was 43 kJ/mol, which is close to that of redox‐induced polymerizations.

Radical Polymerization Behavior of Ethyl α–Naphthoyloxymethylacrylate

Abstract The polymerization of ethyl α-naphthoyloxymethylacrylate (ENMA) with dimethyl 2,2′-azobisisobutyrate (MAIB) in benzene was investigated kinetically and by means of ESR. Polymerization rate (R p) was given by Rp = k[MAIB]0.5[ENMA]1.7 (50°C). The overall activation energy of polymerization was estimated to be 58.4 kJ/mol. The actual polymerization system was found to involve ESR-observable propagating polymer radicals of ENMA. ESR determination of the polymer radical concentration allowed rate constants of propagation (k p) and termination (k t) to be estimated at 60°C: k p = 320 L˙mol−1˙s−1 k t = 3.7 × 105 L˙mol−1˙s−1. Dynamic thermogravimetry showed that the thermal degradation of poly(ENMA) begins at 340°C, and the residue at 500°C was only 4% of the initial polymer. Application of the Kelen–Tüdös method to the copolymerization results of ENMA (M1) and styrene (M2) at 50°C gave the following parameters: r 1 = 0.24 ± 0.01 and r 2 = 0.22 ± 0.01 giving Q 1 = 1.14 and e 1 = +0.78.