Schiff base aluminum compound and preparation method thereof, and preparation method of polylactic acid

A Schiff base aluminum and compound technology, applied in the preparation of polylactic acid, Schiff base aluminum compounds and their preparation fields, can solve the problems of low selectivity and activity of catalytic reactions, and achieve enhanced selectivity, improved regularity, and improved large-scale performance. The effect of steric hindrance

Active Publication Date: 2012-10-31
CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the reported catalysts are all single-metal center Schiff bases obtained by the reaction of salicylaldehyde or substituted salicylaldehyde with diamines, and the selectivity and activity of the catalytic reaction are relatively low.

Method used

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  • Schiff base aluminum compound and preparation method thereof, and preparation method of polylactic acid
  • Schiff base aluminum compound and preparation method thereof, and preparation method of polylactic acid
  • Schiff base aluminum compound and preparation method thereof, and preparation method of polylactic acid

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preparation example Construction

[0054] Optionally, when R is -CH 3 or -CH 2 CH 3 , the present invention also provides a method for preparing a Schiff base aluminum compound, comprising the following steps: combining the Schiff base with the structure of formula (II) and Al(R′) 3 React in a solvent to obtain the Schiff base aluminum compound with the structure of formula (III). Wherein, the solvent is an organic solvent well known to those skilled in the art, preferably tetrahydrofuran or toluene.

[0055] R 1 and R 2 The choice of influences the choice of solvent, when R 1 and R 2 independently selected from -H, -F, -Cl, -Br or -NO 2 When, the reaction solvent is preferably tetrahydrofuran, when R 1 and R 2 independently selected from -CH 3 、-CH 2 CH 3 、-CH(CH 3 ) 2 、-C(CH 3 ) 3 When, the reaction solvent is preferably toluene.

[0056]

[0057]

[0058] R 1 and R 2 independently selected from -H, -CH 3 、-CH 2 CH 3 、-CH(CH 3 ) 2 、-C(CH 3 ) 3 , -F, -Cl, -Br or -NO 2 ;

[005...

Embodiment 1

[0085] Example 1 Preparation of 1,1',3,3'-tetraaminomethylcyclobutane

[0086] 1.1 Add 111.5g of dibromoneopentyl glycol, 50g of benzaldehyde and 0.5g of p-toluenesulfonic acid to 200ml of toluene. Heat to remove water, after removing about 6g of water, no obvious liquid evaporates out, cool down to room temperature, add sodium carbonate solution to wash twice, dry with anhydrous potassium carbonate, rotary evaporate to remove solvent, obtain light yellow oily product, crystallize after cooling 1. After recrystallization from methanol, white crystals were obtained as compound VIa.

[0087] 1.2 Slowly add 2.6g of sodium wire into 100ml of ethanol in an ice bath and protected by argon. After the sodium wire is completely dissolved in ethanol, add 25g of diethyl malonate dropwise. After heating to reflux for 4 hours, add 18g of 1.1 The obtained compound VIa was refluxed for 8 hours, the solvent was removed by rotary evaporation, 150ml of water was added, and extracted 3 times wi...

Embodiment 2

[0099] Embodiment 2 structural formula is the synthesis of the Schiff base IIa of II

[0100] IIa: R 1 =R 2 =-H.

[0101] Dissolve 0.86g of 1,1′,3,3′-tetraaminomethylcyclobutane obtained in 1.7 in 20ml of ethanol, slowly add 2.44g of salicylaldehyde in 50ml of ethanol dropwise, reflux for 12h, and remove by rotary evaporation Most of the solvent was filtered to obtain a yellow powder, which was recrystallized with a mixed solvent of chloroform and ethanol to obtain Schiff base IIa.

[0102] Utilize nuclear magnetic resonance to analyze the Schiff base IIa obtained in embodiment 2, obtain its hydrogen spectrum, the result is as follows:

[0103] 1 HNMR (300.00MHz, CDCl 3 ): δ13.30(s,4H,OH),8.35(s,4H,NCH),6.87~7.36(m,16H,PhH),3.73(s,8H,CH 2 N).

[0104] The Schiff base IIa obtained in Example 2 was analyzed by a mass spectrometer, and the result obtained was: MALDI-TOF (THF), m / z=589.

[0105] The Schiff base IIa obtained in Example 2 was analyzed by elemental analysis t...

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Abstract

The invention provides a Schiff base aluminum compound and a preparation method thereof, and a preparation method of polylactic acid. The structure of the Schiff base aluminum compound is disclosed as Formula (I). Compared with the monometal center Schiff base in the prior art, tetramine compounds are utilized to connect four C=N functional groups, thereby providing two metal active center combination sites and forming a bimetal center Schiff base. On one hand, the bimetal center Schiff base has large molecular space and acquires large steric hindrance, and thus, has higher selectivity for ring-opening polymerization of lactide, thereby enhancing the regularity of the space structure of the polymerisate; and on the other hand, the introduction of the bimetal center improves the reaction activity of the catalyst and enhances the activity of the polymerization reaction.

Description

technical field [0001] The invention belongs to the field of catalysts, and in particular relates to a Schiff base aluminum compound, a preparation method thereof, and a preparation method of polylactic acid. Background technique [0002] Polylactic acid is a chemically synthesized biodegradable material, which is widely used in packaging materials, biomedicine and pharmaceutical industries. The synthesis of polylactic acid usually adopts two methods, namely, ring-opening polymerization of lactide (a cyclic dimer of lactic acid) and direct polymerization of lactic acid. Among them, polylactic acid of macromolecule generally adopts the method of ring-opening polymerization of lactide, and a large number of documents and patents have carried out relevant reports on the ring-opening polymerization of lactide, such as U.S. Patent No. 5235031 and U.S. Patent No. 5357034 US patent. [0003] Lactide is divided into three stereoisomers: L-lactide (LLA), D-lactide (DLA) and meso-la...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07F5/06C08G63/08C08G63/84
Inventor 庞烜段然龙张涵邢璐陈学思庄秀丽
Owner CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI
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