A Schiff base-organic zinc composition, its preparation method and its application in ring-opening polymerization

Abstract

The invention provides a Schiff base-organic zinc composition, which is a Schiff base compound activated by organic zinc; the Schiff base-organic zinc composition in the present invention consists of a Schiff base compound with three active centers and an organic A mixture of zinc compounds. The Schiff base-organic zinc composition provided by the present invention has higher catalytic activity for the ring-opening polymerization of cyclic ester monomers, and has better catalytic performance in a wider temperature range. The mat provided by the present invention The phosphine-organic zinc composition can play a catalytic role at a relatively low concentration, and efficiently catalyze the ring-opening polymerization reaction of ε-caprolactone and lactide. The invention also provides a preparation method of the Schiff base-organic zinc composition and its application in ring-opening polymerization.

Description

technical field

[0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a Schiff base-organic zinc composition, its preparation method and its application in ring-opening polymerization. Background technique

[0002] With social development and scientific and technological progress, people's material living standards continue to improve, but the ensuing environmental problems are becoming increasingly severe. A large amount of plastic waste that is difficult to degrade has become "white pollution", causing great harm to our living space. In recent years, people's awareness of energy saving and environmental protection has been continuously enhanced, and the development of degradable and environmentally friendly polymer materials has become the focus of global attention. As two iconic varieties of synthetic polyester materials, polylactic acid and polycaprolactone have attracted much attention because of their good biocompatibil...

Examples

preparation example Construction

[0036] The present invention also provides a kind of preparation method of Schiff base-organic zinc composition, comprises the following steps:

[0037] Mixing the Schiff base compound with the structure of formula I and the organozinc compound with the structure of formula II, and activating at -20°C to 90°C for 0.5 to 12 hours to obtain the Schiff base-organozinc compound;

[0038] R 1 -Zn-R 2 Formula II;

[0039] In formula I, R is selected from H, substituted or unsubstituted straight chain alkyl, or substituted or unsubstituted branched chain alkyl; n=1 or n=2; X is -(CH 2 )- m , 2≤m≤6; when n=1, Y is O, when n=2, Y is N;

[0040] In formula II, R 1 and R 2 are independently selected from substituted or unsubstituted straight-chain alkyl groups, or substituted or unsubstituted branched-chain alkyl groups.

[0041]In the present invention, the Schiff base compound has the same structure as the above-mentioned Schiff base compound having the structure of formula I,...

Embodiment 1

[0061] Weigh 1.0 g of the salicylaldehyde compound with the structure shown in formula (3) and dissolve it in 50 mL of absolute ethanol, add 2.2 g of N,N-dimethyl-1,3-propanediamine to it, and heat to reflux for 24 hours to react Most of the solvent of the reaction solution is removed by rotary evaporation, and the obtained reaction product is purified by column chromatography, and the Schiff base compound of the structure shown in formula (5) is obtained after separation and treatment.

[0062]

[0063] The resulting Schiff base was subjected to NMR testing, and the 1H NMR analysis results showed: 1H NMR: δ=3.41(m, NCH2CH2CH2N(CH3)2 2H), 2.55(s, ArCCH3 3H), 2.36(m, NCH2CH2CH2N(CH3) 2 2H), 2.22(s, N(CH3)2 6H), 1.81(m, NCH2CH2CH2N(CH3)2 2H).13C NMR: δ=185.44(ArCCH3), all benzenering: 170.34, 105.83; 56.42(NCH2CH2CH2N(CH3 )2), 45.17(NCH2CH2CH2N(CH3)2), 40.87(N(CH3)2, 27.44(NCH2CH2CH2N(CH3)2), 18.06(ArCCH3). NMR test results show that the Schiff base obtained in this embodimen...

Embodiment 2

[0065] Weigh 0.4 g of the salicylaldehyde compound having the structure shown in formula (3) and dissolve it in 50 mL of absolute ethanol, add 0.7 g of N,N-dimethylethylenediamine thereto, and heat to reflux for 24 hours to react; Most of the solvent in the solution, the obtained reaction product is purified by column chromatography, and the Schiff base compound with the structure shown in formula (6) is obtained after separation and treatment.

[0066]

[0067] The obtained Schiff base is carried out nuclear magnetic resonance test, 1 H NMR analysis results show: 1 H NMR: δ=3.44(m, NCH 2 CH 2 N(CH 3 ) 2 2H),2.57(m,NCH 2 CH 2 N(CH 3 ) 2 2H),2.54(s,ArCCH 3 3H),2.27(s,N(CH 3 ) 2 6H). 13 C NMR: δ=185.58 (ArCCH 3 ), all gasoline ring: 170.10, 106.51; 58.17 (NCH 2 CH 2 N(CH 3 ) 2 ),45.36(NCH 2 CH 2 N(CH 3 ) 2 ),41.31(N(CH 3 ) 2 ,18.25 (ArCCH 3 ). NMR test results show that the Schiff base obtained in the present embodiment has a structure shown in form...

technical field

[0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a Schiff base-organic zinc composition, its preparation method and its application in ring-opening polymerization. Background technique

[0002] With social development and scientific and technological progress, people's material living standards continue to improve, but the ensuing environmental problems are becoming increasingly severe. A large amount of plastic waste that is difficult to degrade has become "white pollution", causing great harm to our living space. In recent years, people's awareness of energy saving and environmental protection has been continuously enhanced, and the development of degradable and environmentally friendly polymer materials has become the focus of global attention. As two iconic varieties of synthetic polyester materials, polylactic acid and polycaprolactone have attracted much attention because of their good biocompatibil...

Examples

preparation example Construction

[0036] The present invention also provides a kind of preparation method of Schiff base-organic zinc composition, comprises the following steps:

[0037] Mixing the Schiff base compound with the structure of formula I and the organozinc compound with the structure of formula II, and activating at -20°C to 90°C for 0.5 to 12 hours to obtain the Schiff base-organozinc compound;

[0038] R 1 -Zn-R 2 Formula II;

[0039] In formula I, R is selected from H, substituted or unsubstituted straight chain alkyl, or substituted or unsubstituted branched chain alkyl; n=1 or n=2; X is -(CH 2 )- m , 2≤m≤6; when n=1, Y is O, when n=2, Y is N;

[0040] In formula II, R 1 and R 2 are independently selected from substituted or unsubstituted straight-chain alkyl groups, or substituted or unsubstituted branched-chain alkyl groups.

[0041]In the present invention, the Schiff base compound has the same structure as the above-mentioned Schiff base compound having the structure of formula I,...

Embodiment 1

[0061] Weigh 1.0 g of the salicylaldehyde compound with the structure shown in formula (3) and dissolve it in 50 mL of absolute ethanol, add 2.2 g of N,N-dimethyl-1,3-propanediamine to it, and heat to reflux for 24 hours to react Most of the solvent of the reaction solution is removed by rotary evaporation, and the obtained reaction product is purified by column chromatography, and the Schiff base compound of the structure shown in formula (5) is obtained after separation and treatment.

[0062]

[0063] The resulting Schiff base was subjected to NMR testing, and the 1H NMR analysis results showed: 1H NMR: δ=3.41(m, NCH2CH2CH2N(CH3)2 2H), 2.55(s, ArCCH3 3H), 2.36(m, NCH2CH2CH2N(CH3) 2 2H), 2.22(s, N(CH3)2 6H), 1.81(m, NCH2CH2CH2N(CH3)2 2H).13C NMR: δ=185.44(ArCCH3), all benzenering: 170.34, 105.83; 56.42(NCH2CH2CH2N(CH3 )2), 45.17(NCH2CH2CH2N(CH3)2), 40.87(N(CH3)2, 27.44(NCH2CH2CH2N(CH3)2), 18.06(ArCCH3). NMR test results show that the Schiff base obtained in this embodimen...

Embodiment 2

[0065] Weigh 0.4 g of the salicylaldehyde compound having the structure shown in formula (3) and dissolve it in 50 mL of absolute ethanol, add 0.7 g of N,N-dimethylethylenediamine thereto, and heat to reflux for 24 hours to react; Most of the solvent in the solution, the obtained reaction product is purified by column chromatography, and the Schiff base compound with the structure shown in formula (6) is obtained after separation and treatment.

[0066]

[0067] The obtained Schiff base is carried out nuclear magnetic resonance test, 1 H NMR analysis results show: 1 H NMR: δ=3.44(m, NCH 2 CH 2 N(CH 3 ) 2 2H),2.57(m,NCH 2 CH 2 N(CH 3 ) 2 2H),2.54(s,ArCCH 3 3H),2.27(s,N(CH 3 ) 2 6H). 13 C NMR: δ=185.58 (ArCCH 3 ), all gasoline ring: 170.10, 106.51; 58.17 (NCH 2 CH 2 N(CH 3 ) 2 ),45.36(NCH 2 CH 2 N(CH 3 ) 2 ),41.31(N(CH 3 ) 2 ,18.25 (ArCCH 3 ). NMR test results show that the Schiff base obtained in the present embodiment has a structure shown in form...

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