Radical-initiated homo- and copolymerization of methoxymethyl methacrylate

The kinetics of methoxymethyl methacrylate (MOMA) homopolymerization has been investigated in benzene, using azobis(isobutyronitrile) as an initiator. The rate of polymerization (R_p) could be expressed by R_p = k[AIBN]^0.5 [MOMA]^1.19. The overall activation energy was calculated to be 73.2 kJ/mol. Kinetic constants for MOMA polymerization were obtained as follows: k_p/k_t^1/2 = 0.091 L^1/2 · mol^?1/2 · s^?1/2; 2fk_d = 1.37 × 10^?5 s^?1. The values of K and a in the Mark–Houwink equation, [η] = KM^a, where K = 5.89 × 10^?5 and a = 0.82 when M = M _n and the solvent was benzene. The relative reactivity ratios of MOMA (M₂) copolymerizations with styrene (r₁ = 0.40, r₂ = 0.58) were obtained. Applying the Q-e scheme led to Q = 0.78 and e = 0.67. The glass transition temperature (T_g) of poly(MOMA) was observed to be 64°C by DSC. Thermogravimetry of poly(MOMA) showed a 10% weight loss at 230°C in air.     

Radical heterogeneous polymerization behavior of N‐methyl‐α‐fluoroacrylamide in benzene

The polymerization of N‐methyl‐α‐fluoroacrylamide (NMFAm) initiated with dimethyl 2,2′‐azobisisobutyrate (MAIB) in benzene was studied kinetically and with electron spin resonance. The polymerization proceeded heterogeneously with the highly efficient formation of long‐lived poly(NMFAm) radicals. The overall activation energy of the polymerization was 111 kJ/mol. The polymerization rate (R_p) at 50 °C is given by R_p = k[MAIB]^0.75±0.05 [NMFAm]^0.44±0.05. The concentration of the long‐lived polymer radical increased linearly with time. The formation rate (R_p?) of the long‐lived polymer radical at 50 °C is expressed by R_p? = k[MAIB]^1.0±0.1 [NMFAm]^0±0.1. The overall activation energy of the long‐lived radical formation was 128 kJ/mol, which agreed with the energy of initiation (129 kJ/mol), which was separately estimated. A comparison of R_p? with the initiation rate led to the conclusion that 1‐methoxycarbonyl‐1‐methylethyl radicals (primary radicals from MAIB), escaping from the solvent cage, were quantitatively converted into the long‐lived poly(NMFAm) radicals. Thus, this polymerization involves completely unimolecular termination due to polymer radical occlusion. ¹H NMR‐determined tacticities of resulting poly(NMFAm) were estimated to be rr = 0.34, mr = 0.48, and mm = 0.18. The copolymerization of NMFAm(M₁) and St(M₂) with MAIB at 50 °C in benzene gave monomer reactivity ratios of r₁ = 0.61 and r₂ = 1.79. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2196–2205, 2001     

Radical and cationic polymerizations of 3‐ethyl‐3‐methacryloyloxymethyloxetane

3‐Ethyl‐3‐methacryloyloxymethyloxetane (EMO) was easily polymerized by dimethyl 2,2′‐azobisisobutyrate (MAIB) as the radical initiator through the opening of the vinyl group. The initial polymerization rate (R_p) at 50 °C in benzene was given by R_p = k[MAIB]^0.55 [EMO]^1.2. The overall activation energy of the polymerization was estimated to be 87 kJ/mol. The number‐average molecular weight (M?_n) of the resulting poly(EMO)s was in the range of 1–3.3 × 10⁵. The polymerization system was found to involve electron spin resonance (ESR) observable propagating poly(EMO) radicals under practical polymerization conditions. ESR‐determined rate constants of propagation (k_p) and termination (k_t) at 60 °C are 120 and 2.41 × 10⁵ L/mol s, respectively—much lower than those of the usual methacrylate esters such as methyl methacrylate and glycidyl methacrylate. The radical copolymerization of EMO (M₁) with styrene (M₂) at 60 °C gave the following copolymerization parameters: r₁ = 0.53, r₂ = 0.43, Q₁ = 0.87, and e₁ = +0.42. EMO was also observed to be polymerized by BF₃OEt₂ as the cationic initiator through the opening of the oxetane ring. The M?_n of the resulting polymer was in the range of 650–3100. The cationic polymerization of radically formed poly(EMO) provided a crosslinked polymer showing distinguishably different thermal behaviors from those of the radical and cationic poly(EMO)s. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1269–1279, 2001     

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 (R_p) at 70°C was given by R_p = 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 (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 (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     

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.     

Kinetic study on the radical polymerization of 2‐methacryloyloxyethyl phosphorylcholine

Polymerization of 2‐methacryloyloxyethyl phosphorylcholine (MPC) was kinetically investigated in ethanol using dimethyl 2,2′‐azobisisobutyrate (MAIB) as initiator. The overall activation energy of the homogeneous polymerization was calculated to be 71 kJ/mol. The polymerization rate (R_p) was expressed by R_p = k[MAIB]^0.54±0.05 [MPC]^1.8±0.1. The higher dependence of R_p on the monomer concentration comes from acceleration of propagation due to monomer aggregation and also from retardation of termination due to viscosity effect of the MPC monomer. Rate constants of propagation (k_p) and termination (k_t) of MPC were estimated by means of ESR to be k_p = 180 L/mol · s and k_t = 2.8 × 10⁴ L/mol · s at 60 °C, respectively. Because of much slower termination, R_p of MPC in ethanol was found at 60 °C to be 8 times that of methyl methacrylate (MMA) in benzene, though the different solvents were used for MPC and MMA. Polymerization of MPC with MAIB in ethanol was accelerated by the presence of water and retarded by the presence of benzene or acetonitrile. Poly(MPC) showed a peculiar solubility behavior; although poly(MPC) was highly soluble in ethanol and in water, it was insoluble in aqueous ethanol of water content of 7.4–39.8 vol %. The radical copolymerization of MPC (M₁) and styrene (St) (M₂) in ethanol at 50 °C gave the following copolymerization parameters similar to those of the copolymerization of MMA and St; r₁ = 0.39, r₂ = 0.46, Q₁ = 0.76, and e₁ = +0.51. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 509–515, 2000     

Kinetic study of the radical polymerization behavior of N‐(1‐phenylethylaminocarbonyl)methacrylamide

Polymerization of N‐(1‐phenylethylaminocarbonyl)methacrylamide (PEACMA) with dimethyl 2,2′‐azobisisobutyrate (MAIB) was kinetically studied in dimethyl sulfoxide (DMSO). The overall activation energy of the polymerization was estimated to be 84 kJ/mol. The initial polymerization rate (R_p) is given by R_p = k[MAIB]^0.6[PEACMA]^0.9 at 60 °C, being similar to that of the conventional radical polymerization. The polymerization system involved electron spin resonance (ESR) spectroscopically observable propagating poly(PEACMA) radical under the actual polymerization conditions. ESR‐determined rate constants of propagation and termination were 140 L/mol s and 3.4 × 10⁴ L/mol s at 60 °C, respectively. The addition of LiCl accelerated the polymerization in N,N‐dimethylformamide but did not in DMSO. The copolymerization of PEACMA(M₁) and styrene(M₂) with MAIB in DMSO at 60 °C gave the following copolymerization parameters; r₁ = 0.20, r₂ = 0.51, Q₁ = 0.59, and e₁ = +0.70. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2013–2020, 2005     

Radical polymerization of 3-methylene-5,5′-dimethyl-2-pyrrolidinone: A cyclic analog of N-substituted methacrylamide

3-Methylene-5,5′-dimethyl-2-pyrrolidinone (α-MDMP), a cyclic analog of N-substituted methacrylamide, was synthesized and polymerized with α,α′-azobis (isobutyronitrile) (AIBN) in solution. Poly(α-MDMP) is only soluble in dimethyl sulfoxide (DMSO) at room temperature. Thermogravimetry of poly(α-MDMP) showed 10% weight loss at 355°C in air and 400°C under nitrogen, respectively. The kinetics of α-MDMP homopolymerization with AIBN was investigated in DMSO. The rate of polymerization (R_p) can be expressed by R_p = k[AIBN]^0.49[α-MDMP]^1.0 and the overall activation energy has been calculated to be 73.2 kJ/mol. Monomer reactivity ratios in copolymerization of α-MDMP (M₂) with methyl methacrylate (M₁) are r₁ = 0.71 and r₂ = 0.71, from which Q and e values of α-MDMP are calculated as 0.75 and -0.43, respectively. © 1993 John Wiley & Sons, Inc.     

"CAGE" VANADYL POLYCARBOXYLATE-THIOUREA COMPLEX FOR THE POLYMERIZATION OF ACRYLONITRILE

The polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by " cage " vanadyl polycarboxylate (P=VO)-thiourea (TU) complex was investigated. The overall rate ofpolymerization isThe relationship between the induction period (τ) and the temperature of polymerization as well as the concentrations of reactants can be expressed as follows :The molecular weight of polyacrylonitrile increases with increasing monomer concentration and decreases with increasing temperature of polymerization and concentrations of vanadyl polycarboxylate and thioureaThe polymerization mechanism was proposed and discussed.     

Radical-initiated homo- and copolymerizations of methacryloyl fluoride

The kinetics of methacryloyl fluoride (MAF) homopolymerization was investigated in methyl ethyl ketone (MEK) with azobis(isobutyronitrile) as initiator. The rate of polymerization (R_p) followed the expression R_p = k[AIBN]^0.55[MAF]^1.18. The overall activation energy was calculated as 74.4 kJ/mol. The relative reactivity ratios of MAF(M₂) copolymerization with styrene (r₁ = 0.083, r₂ = 0.14), and methyl methacrylate (r₁ = 0.48, r₂ = 0.81) in methyl ethyl ketone were obtained. Application of the Q–e scheme (in styrene copolymerization) led to Q = 2.22 and e = 1.31. The glass transition temperature (T_g) of poly(MAF) was 90°C by thermomechanical analysis. Thermogravimetry of poly(MAF) showed a 10% weight loss of 228°C in air.     

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. ¹H- and ¹³C-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 (M₁) and styrene (St) (M₂) at 60°C, the monomer reactivity ratios were obtained to be r₁ = 0.02 and r₂ = 0.20, the values of which are similar to those of the copolymerization of ethyl o-formylphenyl fumarate and St. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 563–572, 1998     

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 (R_p) 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. R_p at 50°C in the presence of C₆₀ (7.0 × 10⁻⁵ mol/L) was expressed by R_p = 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-initiated homo- and copolymerization of cyanomethyl methacrylate

The kinetics of cyanomethyl methacrylate (CyMA) homopolymerization was investigated in acetonitrile with azobisisobutyronitrile as initiator. The rate of polymerization R_p was expressed by R_p = k[AIBN]^0.49[CyMA]^1.2 and the overall activation energy was calculated as 72.3 kJ/mol. Kinetic constants for CyMA polymerization were obtained as follows: k_p/k = 0.10 L^1/2s^?1/2; 2fk_d = 1.57 × 10^?5s^?. The relative reactivity ratios of CyMA(M₂) copolymerization with styrene (r₁ = 0.15, r₂ = 0.29) and methyl methacrylate (r₁ = 0.43, r₂ = 0.75) in acetonitrile were obtained. Applying the Q-e scheme (in styrene copolymerization) led to Q = 1.64 and e = 0.98. The glass transition temperature T_g of poly(CyMA) was observed to be 91°C by thermomechanical analysis. Thermogravimetry of poly(CyMA) showed a 10% weight loss at 265°C in air.     

Radical polymerization of N-phenyl-α-methylene-β-lactam

N-phenyl-α-methylene-β-lactam (PML), a cyclic analog of N,N-disubstituted methacrylamides which do not undergo radical homopolymerization, was synthesized and polymerized with α,α′-azobis (isobutyronitrile) (AIBN) in solution. Poly (PML) (PPML) is readily soluble in tetrahydrofuran, chloroform, pyridine, and polar aprotic solvents but insoluble in toluene, ethyl acetate, and methanol. PPML obtained by radical initiation is highly syndiotactic (rr = 92%), exhibits a glass transition at 180°C, and loses no weight upto 330°C in nitrogen. The kinetics of PML homo-polymerization with AIBN was investigated in N-methyl-2-pyrrolidone. The rate of polymerization (R_p) can be expressed by R_p = k[AIBN]^0.55[PML]^1.2 and the overall activation energy has been calculated to be 87.3 kJ/mol. Monomer reactivity ratios in copolymerization of PML (M₂) with styrene (M₁) are r₁ = 0.67 and r₂ = 0.41, from which Q and e values of PML are calculated as 0.60 and 0.33, respectively.     

Elementary reaction analysis of the radical polymerization of α‐ethyl β‐N‐(α′‐methylbenzyl)itaconamates carrying (RS)‐ and (S)‐α‐methylbenzylaminocarbonyl groups

The polymerizations of α‐ethyl β‐N‐(α′‐methylbenzyl)itaconamates carrying (RS)‐ and (S)‐α‐methylbenzylaminocarbonyl groups (RS‐EMBI and S‐EMBI) with dimethyl 2,2′‐azobisisobutyrate (MAIB) were studied in methanol (MeOH) and in benzene kinetically and with electron spin resonance (ESR) spectroscopy. The initial polymerization rate (R_p) at 60 °C was given by R_p = k[MAIB]^{0.58 ± 0.05}[RS‐EMBI]^{2.4 ± 0.l} and R_p = k[MAIB]^{0.61 ± 0.05}[S‐EMBI]^{2.3 ± 0.l} in MeOH and R_p = k[MAIB]^{0.54 ± 0.05}[RS‐EMBI]^{1.7 ± 0.l} in benzene. The rate constants of initiation (k_df), propagation (k_p), and termination (k_t) as elementary reactions were estimated by ESR, where k_d is the rate constant of MAIB decomposition and f is the initiator efficiency. The k_p values of RS‐EMBI (0.50–1.27 L/mol s) and S‐EMBI (0.42–1.32 L/mol s) in MeOH increased with increasing monomer concentrations, whereas the k_t values (0.20?7.78 × 10⁵ L/mol s for RS‐EMBI and 0.18?6.27 × 10⁵ L/mol s for S‐EMBI) decreased with increasing monomer concentrations. Such relations of R_p with k_p and k_t were responsible for the unusually high dependence of R_p on the monomer concentration. The activation energies of the elementary reactions were also determined from the values of k_df, k_p, and k_t at different temperatures. R_p and k_p of RS‐EMBI and S‐EMBI in benzene were considerably higher than those in MeOH. R_p of RS‐EMBI was somewhat higher than that of S‐EMBI in both MeOH and benzene. Such effects of the kinds of solvents and monomers on R_p were explicable in terms of the different monomer associations, as analyzed by ¹H NMR. The copolymerization of RS‐EMBI with styrene was examined at 60 °C in benzene. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1819–1830, 2003     

Radical-initiated homopolymerization and copolymerization of ethyl α-hydroxymethylacrylate

Ethyl α-hydroxymethylacrylate (EHMA) was synthesized and homopolymerized in bulk and in solution. The poly(EHMA) is readily soluble in alcohol, acetone, tetrahydrofuran, and methylene chloride at room temperature. Intramolecular lactone formation occurred when poly(EHMA) was heated to 180–230°C. The kinetics of EHMA homopolymerization was investigated in ethyl acetate, using α,α′-azobisisobutylonitrile as an initiator. The rate of polymerization R_p was expressed by R_p = k[AIBN]^0.50[EHMA]^1.4 and the overall activation energy was calculated as 71.9 kJ/mol. Kinetic constants for EHMA polymerization were obtained as follows: k_p/k = 0.17L^0.9mol^?0.9s^?0.5; 2fk_d = 1.5 × 10^?5 s^?1. The relative reactivity ratios of EHMA(M₂) copolymerization with styrene (r₁ = 0.472, r₂ = 0.564) in ethyl acetate were obtained. Applying the Q-e scheme led to Q = 0.84 and e = 0.35 for EHMA.     

Polymerization of α-methylene-N-methylpyrrolidone

α-Methylene-N-methylpyrrolidone (α-MMP) was synthesized and homopolymerized by bulk and solution methods. The poly(α-MMP) is readily soluble in water, methanol, methylene chloride, and dipolar aprotic solvents at room temperature. Thermogravimetric analysis of poly(α-MMP) showed a 10% weight loss at 330°C in air. The kinetics of α-MMP homopolymerization and copolymerization were investigated in acetonitrile, using azobisisobutyronitrile (AIBN) as an initiator. The rate of polymerization R_p could be expresed by R_p = k[AIBN]^0.49[α-MMP]^1.3. The overall activation energy was calculated to be 84.1 kj/mol. The relative reactivity ratios of α-MMP (M₂) copolymerization with methyl methacrylate (r₁ = 0.59, r₂ = 0.26) in acetonitrile were obtained. Applying the Q-e scheme led to Q = 2.18 and e = 1.77. These Q and e values are larger than those for acrylamide derivatives.     

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

Free‐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 (R_p) equation was R_p ∝ [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     

Radical polymerization behavior of trimethoxyvinylsilane

Trimethoxyvinylsilane (TMVS) was quantitatively polymerized at 130 °C in bulk, using dicumyl peroxide (DCPO) as initiator. The polymerization of TMVS with DCPO was kinetically studied in dioxane by Fourier transform near‐infrared spectroscopy. The overall activation energy of the bulk polymerization was estimated to be 112 kJ/mol. The initial polymerization rate (R_p) was expressed by R_p = k[DCPO]^0.6[TMVS]^1.0 at 120 °C, being closely similar to that of the conventional radical polymerization involving bimolecular termination. The polymerization system involved electron spin resonance (ESR) spectroscopically observable polymer radicals under the actual polymerization conditions. ESR‐determined apparent rate constants of propagation and termination were 13 L/mol s and 3.1 × 10⁴ L/mol s at 120 °C, respectively. The molecular weight of the resulting poly(TMVS)s was low (M_n = 2.0–4.4 × 10³), because of the high chain transfer constant (C_mtr = 4.2 × 10^?2 at 120 °C) to the monomer. The bulk copolymerization of TMVS (M₁) and vinyl acetate (M₂) at 120 °C gave the following copolymerization parameters: r_l = 1.4, r₂ = 0.24, Q₁ = 0.084, and e₁ = +0.80. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5864–5871, 2005     

Polymerization of Methyl Methacrylate in the Presence of Imidazole Derivatives. Kinetics and Polymer Structure

The kinetics of the polymerization of methyl methacrylate (MMA) in the presence of imidazole (Im), 2-methylimidazole (2MIm), or benz-imidazole (BIm) in tetrahydrofuran (THF) at 15–40°C was investigated by dilatometry. The rate of polymerization, R_p , was expressed by R_p = k[Im] [MMA]², where k = 3.0 × 10^?6 L²/(mol² s) in THF at 30°C. The overall activation energy, E_a , was 6.9 kcal/mol for the Im system and 7.3 kcal/mol for the 2MIm system. The relation between logR_p and 1 T was not linear for the BIm system. The polymers obtained were soluble in acetone, chloroform, benzene, and THF. The melting points of the polymers were in the range of 258–280°C. The ¹H-NMR spectra indicated that the polymers were made up of about 58–72% of syndiotactic structure. The polymerization mechanism is discussed on the basis of these results.