Irganox 1076 antioxidant

Example 7

2 ml of isoprene equal to about 1.36 g were placed in a 25 ml test tube. Subsequently, 14 ml of toluene were added and the temperature of the solution thus obtained was brought to +20° C. Then, methylaluminoxane (MAO) in toluene solution (0.315 ml; 5×10⁻⁴ moles, equal to about 0.029 g) was added and, subsequently, the FeCl₂(L1) complex [sample MG215] (1.7 ml of toluene solution at a concentration of 2 mg/ml; 1×10⁻⁵, equal to about 3.37 mg) obtained as described in Example 5. Everything was kept under magnetic stirring, at ambient temperature, for 5 minutes. The polymerization was then quenched by adding 2 ml of methanol containing some drops of hydrochloric acid. The polymer obtained was then coagulated by adding 40 ml of a methanol solution containing 4% of Irganox® 1076 antioxidant (Ciba) obtaining 1.36 g of polyisoprene for a conversion equal to 100%, having a mainly alternating cis-1,4/3,4 structure: further characteristics of the process and of the polyisoprene obtained are reported in Table 1.

FIG. 4 shows the FT-IR spectrum of the polyisoprene obtained.

FIG. 5 shows the ¹H-NMR (top) and ¹³C-NMR (bottom) spectra of the polyisoprene obtained. Table 2 shows the attribution of the different peaks present in the olefinic zone of the ¹³C-NMR spectrum.

Example 22

2 ml of 1,3-butadiene equal to about 1.4 g were condensed, cold (−20° C.) in a 25 ml test tube. Subsequently, 7.4 ml of toluene were added and the temperature of the solution thus obtained was brought to 25° C. Then, methylaluminoxane (MAO) in toluene solution (6.3 ml; 1×10⁻² moles, equal to about 0.58 g) was added and, subsequently, the TiCl₄(L4) complex [sample MG271] (2.3 ml of toluene suspension at a concentration of 2 mg/ml; 1×10⁻⁵, equal to about 4.54 mg) obtained as described in Example 13. Everything was kept under magnetic stirring, at 25° C., for 30 minutes. The polymerization was then stopped by adding 2 ml of methanol containing some drops of hydrochloric acid (37% by weight aqueous solution). The polymer obtained was then coagulated by adding 40 ml of a methanol solution containing 4% of Irganox® 1076 antioxidant (Ciba) obtaining 0.43 g of polybutadiene having a 1,4-cis unit content of 73%: further characteristics of the procedure and of the polybutadiene obtained are reported in Table 1.

FIG. 23 shows the FT-IR spectrum of the polybutadiene obtained.

Example 24

2 ml of 1,3-butadiene equal to about 1.4 g were condensed, cold (−20° C.) in a 25 ml test tube. Subsequently, 11.5 ml of toluene were added and the temperature of the solution thus obtained was brought to 25° C. Then, methylaluminoxane (MAO) in toluene solution (3.15 ml; 5×10⁻³ moles, equal to about 0.27 g) was added and, subsequently, the TiCl₄(L5) complex [sample MG284] (1.4 ml of toluene suspension at a concentration of 2 mg/ml; 1×10⁻⁶, equal to about 2.81 mg) obtained as described in Example 14. Everything was kept under magnetic stirring, at 25° C., for 60 minutes. The polymerization was then stopped by adding 2 ml of methanol containing some drops of hydrochloric acid (37% by weight aqueous solution). The polymer obtained was then coagulated by adding 40 ml of a methanol solution containing 4% of Irganox® 1076 antioxidant (Ciba) obtaining 1.12 g of polybutadiene having a 1,4-cis unit content of 60%: further characteristics of the procedure and of the polybutadiene obtained are reported in Table 1.

FIG. 24 shows the FT-IR spectrum of the polybutadiene obtained.

Example 22

2 ml of 1,3-butadiene equal to about 1.4 g were condensed, cold (−20° C.) in a 25 ml test tube. Subsequently, 8.02 ml of toluene were added and the temperature of the solution thus obtained was brought to 20° C. Then, methylaluminoxane (MAO) in toluene solution (6.3 ml; 1×10⁻² moles, equal to about 0.58 g) was added and, subsequently, the TiCl₃(L4) complex [sample MT-11] (1.68 ml of toluene suspension at a concentration equal to 2 mg/ml; 1×10⁻⁵ moles, equal to about 3.36 mg) obtained as described in Example 12. The whole was kept under magnetic stirring, at 20° C., for 65 minutes. The polymerization was then stopped by adding 2 ml of methanol containing some drops of hydrochloric acid. The polymer obtained was then coagulated by adding 40 ml of a methanol solution containing 4% of Irganox® 1076 antioxidant (Ciba) obtaining 0.719 g of polybutadiene with a prevalently 1,4-cis structure having a 1,4-cis unit content equal to 87.1%: further characteristics of the procedure and of the polybutadiene obtained are reported in Table 1.

FIG. 16 shows the FT-IR spectrum of the polybutadiene obtained.

Example 25

2 ml of 1,3-butadiene equal to about 1.4 g were condensed, cold (−20° C.) in a 25 ml test tube. Subsequently, 7.8 ml of toluene were added and the temperature of the solution thus obtained was brought to 20° C. Then, methylaluminoxane (MAO) in toluene solution (6.3 ml; 1×10⁻² moles, equal to about 0.58 g) was added and, subsequently, the TiCl₂(THF)(L1) complex [sample MT-22] (1.89 ml of toluene suspension at a concentration equal to 2 mg/ml; 1×10⁻⁵ moles, equal to about 3.78 mg) obtained as described in Example 15. The whole was kept under magnetic stirring, at 20° C., for 5 minutes. The polymerization was then stopped by adding 2 ml of methanol containing some drops of hydrochloric acid. The polymer obtained was then coagulated by adding 40 ml of a methanol solution containing 4% of Irganox® 1076 antioxidant (Ciba) obtaining 1.4 g of polybutadiene with a prevalently 1,4-cis structure having a 1,4-cis unit content equal to 84.4%: further characteristics of the procedure and of the polybutadiene obtained are reported in Table 1.

FIG. 20 shows the FT-IR spectrum of the polybutadiene obtained.

Example 20

2 ml of 1,3-butadiene equal to about 1.4 g were condensed, cold (−20° C.) in a 25 ml test tube. Subsequently, 7.5 ml of toluene were added and the temperature of the solution thus obtained was brought to 20° C. Then, methylaluminoxane (MAO) in toluene solution (6.3 ml; 1×10⁻² moles, equal to about 0.58 g) was added and, subsequently, the TiCl₄(L2) complex [sample BM2-211] (2.18 ml of toluene suspension at a concentration equal to 2 mg/ml; 1×10⁻⁵ moles, equal to about 4.36 mg) obtained as described in Example 9. The whole was kept under magnetic stirring, at 20° C., for 60 minutes. The polymerization was then stopped by adding 2 ml of methanol containing some drops of hydrochloric acid. The polymer obtained was then coagulated by adding 40 ml of a methanol solution containing 4% of Irganox® 1076 antioxidant (Ciba) obtaining 0.270 g of polybutadiene with a prevalently 1,4-cis structure having a 1,4-cis unit content equal to 82.2%: further characteristics of the procedure and of the polybutadiene obtained are reported in Table 1.

FIG. 12 shows the FT-IR spectrum of the polybutadiene obtained.

Example 21

2 ml of 1,3-butadiene equal to about 1.4 g were condensed, cold (−20° C.) in a 25 ml test tube. Subsequently, 7.4 ml of toluene were added and the temperature of the solution thus obtained was brought to 20° C. Then, methylaluminoxane (MAO) in toluene solution (6.3 ml; 1×10⁻² moles, equal to about 0.58 g) was added and, subsequently, the TiCl₃(L1) complex [sample BM2-227] (2.32 ml of toluene suspension at a concentration equal to 2 mg/ml; 1×10⁻⁵ moles, equal to about 4.64 mg) obtained as described in Example 11. The whole was kept under magnetic stirring, at 20° C., for 7 minutes. The polymerization was then stopped by adding 2 ml of methanol containing some drops of hydrochloric acid. The polymer obtained was then coagulated by adding 40 ml of a methanol solution containing 4% of Irganox® 1076 antioxidant (Ciba) obtaining 0.601 g of polybutadiene with a prevalently 1,4-cis structure having a 1,4-cis unit content equal to 82.5%: further characteristics of the procedure and of the polybutadiene obtained are reported in Table 1.

FIG. 13 shows the FT-IR spectrum of the polybutadiene obtained.

FIG. 14 shows the GPC diagram of the polybutadiene obtained.

FIG. 15 shows the ¹H-NMR (bottom) and ¹³C-NMR (top) spectra of the polybutadiene obtained.