Investigation of the radical copolymerization and terpolymerization of maleic anhydride and norbornenes by anin situ1H NMR analysis of kinetics and by the mercury method: Evidence for the lack of charge-transfer-complex propagation

Abstract

The radical copolymerization of electron‐deficient maleic anhydride (MA) and electron‐rich norbornene (NB) derivatives with 2,2′‐azobis(isobutyronitrile) (AIBN) in dioxane‐d8 has been monitored in situ by 1H NMR spectroscopy with free induction decays recorded every 30 min at 60, 70, or 84 °C. The ratios of the monomer pairs were varied in some cases. The NB derivatives employed in this study included bicyclo[2.2.1]hept‐2‐ene (NB), t‐butyl 5‐norbornene‐2‐carboxylate, methyl 5‐norbornene‐2‐methyl‐2‐carboxylate, and ethyl tetracyclo[4.4.0.12,5.17,10]dodec‐3‐ene‐8‐carboxylate. Decomposition of AIBN, consumption of the monomers, feed ratios, endo/exo ratios, copolymer compositions, and copolymer yields were studied as a function of polymerization time. Furthermore, a homopolymerizable third monomer (t‐butyl methacrylate, methacrylic acid, t‐butyl acrylate, or acrylic acid) was added to the NB/MA 1/1 system, revealing that the methacrylic monomer polymerizes rapidly in the early stage and that the ratio of MA to NB in the terpolymer strongly deviates from 1/1. In contrast, however, the acrylic monomers are more uniformly incorporated into the polymer. Nevertheless, these studies indicate that MA and NB do not always behave as a pair in radical polymerization and disproves the commonly believed charge‐transfer mechanism. Electron‐deficient fumaronitrile was also included in the kinetics study. To further understand the copolymerization mechanism, MA and NB were competitively reacted with a cyclohexyl radical generated by the treatment of cyclohexylmercuric chloride with sodium borohydride (mercury method). A gas chromatographic analysis of the reaction mixtures has revealed that a cyclohexyl radical reacts with MA almost exclusively in competition and that the cyclohexyl adduct of MA essentially accounts for all the products in a mass balance experiment, eliminating a possibility of the formation of an adduct involving the MA–NB charge‐transfer complex. Thus, the participation of a charge‐transfer complex in the copolymerization of MA and NB cannot be important. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3521–3542, 2000

Fundamental Investigations of the Free Radical Copolymerization and Terpolymerization of Maleic Anhydride, Norbornene, and Norbornene tert-Butyl Ester: In-Situ Mid-Infrared Spectroscopic Analysis

“…In addition, the conversion of Nb and MAH was disrupted more in the presence of tBMA, and only low conversion of Nb occurred in the reaction with tBMA. This observation agrees well with Ito's earlier efforts; however, molecular weight and molecular weight distribution data were not presented. The yield of the 50/50/15 Nb/MAH/tBA terpolymerization was 83% with a number-average molecular weight of 7800 ( M w / M n = 1.74) using MALLS detection.…”

Fundamental Investigations of the Free Radical Copolymerization and Terpolymerization of Maleic Anhydride, Norbornene, and Norbornene tert-Butyl Ester: In-Situ Mid-Infrared Spectroscopic Analysis

“…In addition, the conversion of Nb and MAH was disrupted more in the presence of tBMA, and only low conversion of Nb occurred in the reaction with tBMA. This observation agrees well with Ito's earlier efforts; however, molecular weight and molecular weight distribution data were not presented. The yield of the 50/50/15 Nb/MAH/tBA terpolymerization was 83% with a number-average molecular weight of 7800 ( M w / M n = 1.74) using MALLS detection.…”

Radical copolymerization of 2‐trifluoromethylacrylic monomers. I. Kinetics of their copolymerization with norbornenes and vinyl ethers as studied by in situ1H NMR analysis

“…10). This terpolymerization behavior was very similar to that of MA, TBMA, and NB 21. When TBMA was replaced with TBA, the terpolymerization ([TFMAA] 0 = 0.655 mol/L, [TBA] 0 = 0.684 mol/L, and [NB] 0 = 0.665 mol/L) became more homogeneous because TFMAA and TBA reacted at about the same rates (Fig.…”

“…9). The NB incorporation in this case was slightly lower than 50 mol %, which was just like the MA–NB copolymerization21 but significantly different from the TFMA–NB copolymerization. MTFMA can compete well with MA in reaction with NB.…”

“…Decomposition of AIBN and the formation of 1,1,2,2‐tetramethylsuccinodinitrile through primary radical recombination were monitored in this copolymerization, following the disappearance of the AIBN methyl resonance and appearance of the methyl signal of the coupling product, in a fashion similar to the previously reported procedure 21. The concentration of the radicals reacting with the monomers was calculated from the AIBN decomposition kinetics data assuming the recombination as the only radical waste process (assuming that disproportionation is negligible).…”

Aliphatic platforms for the design of 157-nm chemically amplified resists

“…Therefore, the copolymerizations were treated by the penultimate model requiring four reactivity ratios, which explained the copolymerization behavior satisfactorily. in situ 1 H NMR analysis of the radical copolymerization kinetics was carried out, as described before, 8,9 using AIBN as the initiator in 1,4-dioxane-d 8 as a polymerization and NMR solvent on a Bruker AC300 300 MHz 1 H NMR spectrometer. 1 H and 13 C NMR spectra were obtained at room temperature on a Bruker AF250 or Avance 400 spectrometer.…”

Fundamental Investigations of the Free Radical Copolymerization and Terpolymerization of Maleic Anhydride, Norbornene, and Norbornene tert-Butyl Ester: In-Situ Mid-Infrared Spectroscopic Analysis

“…In addition, the conversion of Nb and MAH was disrupted more in the presence of tBMA, and only low conversion of Nb occurred in the reaction with tBMA. This observation agrees well with Ito's earlier efforts; however, molecular weight and molecular weight distribution data were not presented. The yield of the 50/50/15 Nb/MAH/tBA terpolymerization was 83% with a number-average molecular weight of 7800 ( M w / M n = 1.74) using MALLS detection.…”

Radical copolymerization of 2‐trifluoromethylacrylic monomers. I. Kinetics of their copolymerization with norbornenes and vinyl ethers as studied by in situ1H NMR analysis

“…10). This terpolymerization behavior was very similar to that of MA, TBMA, and NB 21. When TBMA was replaced with TBA, the terpolymerization ([TFMAA] 0 = 0.655 mol/L, [TBA] 0 = 0.684 mol/L, and [NB] 0 = 0.665 mol/L) became more homogeneous because TFMAA and TBA reacted at about the same rates (Fig.…”

“…9). The NB incorporation in this case was slightly lower than 50 mol %, which was just like the MA–NB copolymerization21 but significantly different from the TFMA–NB copolymerization. MTFMA can compete well with MA in reaction with NB.…”

“…Decomposition of AIBN and the formation of 1,1,2,2‐tetramethylsuccinodinitrile through primary radical recombination were monitored in this copolymerization, following the disappearance of the AIBN methyl resonance and appearance of the methyl signal of the coupling product, in a fashion similar to the previously reported procedure 21. The concentration of the radicals reacting with the monomers was calculated from the AIBN decomposition kinetics data assuming the recombination as the only radical waste process (assuming that disproportionation is negligible).…”

Aliphatic platforms for the design of 157-nm chemically amplified resists

“…Therefore, the copolymerizations were treated by the penultimate model requiring four reactivity ratios, which explained the copolymerization behavior satisfactorily. in situ 1 H NMR analysis of the radical copolymerization kinetics was carried out, as described before, 8,9 using AIBN as the initiator in 1,4-dioxane-d 8 as a polymerization and NMR solvent on a Bruker AC300 300 MHz 1 H NMR spectrometer. 1 H and 13 C NMR spectra were obtained at room temperature on a Bruker AF250 or Avance 400 spectrometer.…”

Fundamental Investigations of the Free Radical Copolymerization and Terpolymerization of Maleic Anhydride, Norbornene, and Norbornene tert-Butyl Ester: In-Situ Mid-Infrared Spectroscopic Analysis

“…In addition, the conversion of Nb and MAH was disrupted more in the presence of tBMA, and only low conversion of Nb occurred in the reaction with tBMA. This observation agrees well with Ito's earlier efforts; however, molecular weight and molecular weight distribution data were not presented. The yield of the 50/50/15 Nb/MAH/tBA terpolymerization was 83% with a number-average molecular weight of 7800 ( M w / M n = 1.74) using MALLS detection.…”

Radical copolymerization of 2‐trifluoromethylacrylic monomers. I. Kinetics of their copolymerization with norbornenes and vinyl ethers as studied by in situ1H NMR analysis

“…10). This terpolymerization behavior was very similar to that of MA, TBMA, and NB 21. When TBMA was replaced with TBA, the terpolymerization ([TFMAA] 0 = 0.655 mol/L, [TBA] 0 = 0.684 mol/L, and [NB] 0 = 0.665 mol/L) became more homogeneous because TFMAA and TBA reacted at about the same rates (Fig.…”

“…9). The NB incorporation in this case was slightly lower than 50 mol %, which was just like the MA–NB copolymerization21 but significantly different from the TFMA–NB copolymerization. MTFMA can compete well with MA in reaction with NB.…”

“…Decomposition of AIBN and the formation of 1,1,2,2‐tetramethylsuccinodinitrile through primary radical recombination were monitored in this copolymerization, following the disappearance of the AIBN methyl resonance and appearance of the methyl signal of the coupling product, in a fashion similar to the previously reported procedure 21. The concentration of the radicals reacting with the monomers was calculated from the AIBN decomposition kinetics data assuming the recombination as the only radical waste process (assuming that disproportionation is negligible).…”

Aliphatic platforms for the design of 157-nm chemically amplified resists

“…Therefore, the copolymerizations were treated by the penultimate model requiring four reactivity ratios, which explained the copolymerization behavior satisfactorily. in situ 1 H NMR analysis of the radical copolymerization kinetics was carried out, as described before, 8,9 using AIBN as the initiator in 1,4-dioxane-d 8 as a polymerization and NMR solvent on a Bruker AC300 300 MHz 1 H NMR spectrometer. 1 H and 13 C NMR spectra were obtained at room temperature on a Bruker AF250 or Avance 400 spectrometer.…”