CN115073418A - Magnesium catalyst and method for recovering racemic lactide by depolymerizing high-regularity polylactic acid by using same - Google Patents
Magnesium catalyst and method for recovering racemic lactide by depolymerizing high-regularity polylactic acid by using same Download PDFInfo
- Publication number
- CN115073418A CN115073418A CN202210890799.0A CN202210890799A CN115073418A CN 115073418 A CN115073418 A CN 115073418A CN 202210890799 A CN202210890799 A CN 202210890799A CN 115073418 A CN115073418 A CN 115073418A
- Authority
- CN
- China
- Prior art keywords
- polylactic acid
- regularity
- depolymerizing
- lactide
- highly regular
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229920000747 poly(lactic acid) Polymers 0.000 title claims abstract description 85
- 239000004626 polylactic acid Substances 0.000 title claims abstract description 85
- JJTUDXZGHPGLLC-UHFFFAOYSA-N lactide Chemical compound CC1OC(=O)C(C)OC1=O JJTUDXZGHPGLLC-UHFFFAOYSA-N 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 32
- 239000003054 catalyst Substances 0.000 title claims abstract description 14
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 title abstract description 5
- 229910052749 magnesium Inorganic materials 0.000 title abstract description 5
- 239000011777 magnesium Substances 0.000 title abstract description 5
- DGEZNRSVGBDHLK-UHFFFAOYSA-N [1,10]phenanthroline Chemical compound C1=CN=C2C3=NC=CC=C3C=CC2=C1 DGEZNRSVGBDHLK-UHFFFAOYSA-N 0.000 claims abstract description 13
- 230000008569 process Effects 0.000 claims abstract description 13
- 239000011701 zinc Substances 0.000 claims abstract description 13
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 11
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims abstract description 10
- 238000011065 in-situ storage Methods 0.000 claims abstract description 6
- 150000003752 zinc compounds Chemical class 0.000 claims abstract description 5
- JJTUDXZGHPGLLC-ZXZARUISSA-N (3r,6s)-3,6-dimethyl-1,4-dioxane-2,5-dione Chemical compound C[C@H]1OC(=O)[C@H](C)OC1=O JJTUDXZGHPGLLC-ZXZARUISSA-N 0.000 claims description 12
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 claims description 4
- ZOIORXHNWRGPMV-UHFFFAOYSA-N acetic acid;zinc Chemical compound [Zn].CC(O)=O.CC(O)=O ZOIORXHNWRGPMV-UHFFFAOYSA-N 0.000 claims description 2
- 238000012691 depolymerization reaction Methods 0.000 claims description 2
- 239000004246 zinc acetate Substances 0.000 claims description 2
- 239000011592 zinc chloride Substances 0.000 claims description 2
- 235000005074 zinc chloride Nutrition 0.000 claims description 2
- -1 zinc metal compound Chemical class 0.000 claims 1
- 238000006731 degradation reaction Methods 0.000 abstract description 9
- 230000015556 catabolic process Effects 0.000 abstract description 8
- 229920001432 poly(L-lactide) Polymers 0.000 abstract description 8
- JVTAAEKCZFNVCJ-REOHCLBHSA-N L-lactic acid Chemical compound C[C@H](O)C(O)=O JVTAAEKCZFNVCJ-REOHCLBHSA-N 0.000 abstract description 7
- 238000004064 recycling Methods 0.000 abstract description 4
- 239000002699 waste material Substances 0.000 abstract description 4
- 238000011031 large-scale manufacturing process Methods 0.000 abstract description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 238000006243 chemical reaction Methods 0.000 description 18
- 238000010438 heat treatment Methods 0.000 description 10
- 238000004128 high performance liquid chromatography Methods 0.000 description 10
- 239000000463 material Substances 0.000 description 10
- 238000001228 spectrum Methods 0.000 description 10
- 238000005303 weighing Methods 0.000 description 9
- 238000004821 distillation Methods 0.000 description 8
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 239000003208 petroleum Substances 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229920003023 plastic Polymers 0.000 description 3
- 239000004033 plastic Substances 0.000 description 3
- 238000007151 ring opening polymerisation reaction Methods 0.000 description 3
- 208000003643 Callosities Diseases 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 206010020649 Hyperkeratosis Diseases 0.000 description 2
- 241000209149 Zea Species 0.000 description 2
- 235000005824 Zea mays ssp. parviglumis Nutrition 0.000 description 2
- 235000002017 Zea mays subsp mays Nutrition 0.000 description 2
- 235000005822 corn Nutrition 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000002028 Biomass Substances 0.000 description 1
- OYBMVMAXKOGYDC-UHFFFAOYSA-N CTPB Chemical compound CCCCCCCCCCCCCCCC1=CC=CC(OCC)=C1C(=O)NC1=CC=C(Cl)C(C(F)(F)F)=C1 OYBMVMAXKOGYDC-UHFFFAOYSA-N 0.000 description 1
- JVTAAEKCZFNVCJ-UWTATZPHSA-N D-lactic acid Chemical compound C[C@@H](O)C(O)=O JVTAAEKCZFNVCJ-UWTATZPHSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229920003232 aliphatic polyester Polymers 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 150000003983 crown ethers Chemical class 0.000 description 1
- 229940022769 d- lactic acid Drugs 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 229920006126 semicrystalline polymer Polymers 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D319/00—Heterocyclic compounds containing six-membered rings having two oxygen atoms as the only ring hetero atoms
- C07D319/10—1,4-Dioxanes; Hydrogenated 1,4-dioxanes
- C07D319/12—1,4-Dioxanes; Hydrogenated 1,4-dioxanes not condensed with other rings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
- B01J31/18—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes containing nitrogen, phosphorus, arsenic or antimony as complexing atoms, e.g. in pyridine ligands, or in resonance therewith, e.g. in isocyanide ligands C=N-R or as complexed central atoms
- B01J31/1805—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes containing nitrogen, phosphorus, arsenic or antimony as complexing atoms, e.g. in pyridine ligands, or in resonance therewith, e.g. in isocyanide ligands C=N-R or as complexed central atoms the ligands containing nitrogen
- B01J31/181—Cyclic ligands, including e.g. non-condensed polycyclic ligands, comprising at least one complexing nitrogen atom as ring member, e.g. pyridine
- B01J31/1825—Ligands comprising condensed ring systems, e.g. acridine, carbazole
- B01J31/183—Ligands comprising condensed ring systems, e.g. acridine, carbazole with more than one complexing nitrogen atom, e.g. phenanthroline
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
- B01J31/22—Organic complexes
- B01J31/2204—Organic complexes the ligands containing oxygen or sulfur as complexing atoms
- B01J31/2208—Oxygen, e.g. acetylacetonates
- B01J31/2226—Anionic ligands, i.e. the overall ligand carries at least one formal negative charge
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
- B01J2531/02—Compositional aspects of complexes used, e.g. polynuclearity
- B01J2531/0238—Complexes comprising multidentate ligands, i.e. more than 2 ionic or coordinative bonds from the central metal to the ligand, the latter having at least two donor atoms, e.g. N, O, S, P
- B01J2531/0241—Rigid ligands, e.g. extended sp2-carbon frameworks or geminal di- or trisubstitution
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
- B01J2531/20—Complexes comprising metals of Group II (IIA or IIB) as the central metal
- B01J2531/26—Zinc
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
- C07B2200/00—Indexing scheme relating to specific properties of organic compounds
- C07B2200/07—Optical isomers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/62—Plastics recycling; Rubber recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Catalysts (AREA)
Abstract
The invention discloses a magnesium catalyst and a method for depolymerizing high-regularity polylactic acid and recovering racemic lactide by using the same, and belongs to the technical field of degradation of high-regularity polylactic acid. The invention solves the problems that the degradation of the existing polylactic acid is mostly PLLA and the degradation of the polylactic acid with high stereoregularity is lacked. The invention adopts the zinc complex catalyst prepared by inorganic zinc compound and 1, 10-phenanthroline in situ to catalyze and degrade the polylactic acid with high regularity under the conditions of high temperature and high vacuum degree, thereby realizing the recycling of the waste polylactic acid with the regularity higher than 85%. The zinc complex catalyst adopted by the invention only needs to be prepared in situ in the depolymerization process, so that the production cost is more economic, and the method is suitable for large-scale production.
Description
Technical Field
The invention relates to a magnesium catalyst and a method for depolymerizing high-regularity polylactic acid and recovering racemic lactide by using the same, belonging to the technical field of degradation of high-regularity polylactic acid.
Background
The most important of petroleum compounds is plastic, which is the largest synthetic consumer product in the world, but petroleum resources are limited and non-renewable, and in order to realize sustainable development, one of the objectives is to find a substitute for the existing plastic, and aliphatic polyester biomass materials are long used as a substitute for petroleum-derived materials, wherein polylactic acid materials are derived from natural corns, the corns are widely planted, the yield is stable, and the polylactic acid materials belong to completely biodegradable environment-friendly materials, can be naturally decomposed into carbon dioxide and water in the nature through the action of microorganisms in the nature, and are expected to become a substitute for traditional petroleum-based source plastics.
Research shows that the main chain structure, especially the tacticity, of polylactic acid has important influence on the performance of polylactic acid, and the levorotatory polylactic acid PLLA prepared from the levorotatory lactide L-LA is a polylactic acid material widely applied at present, and the polylactic acid has a melting point of 160-170 ℃ as a semi-crystalline polymer. In order to further obtain a polylactic acid material with higher performance, a great deal of research on polylactic acid with high stereoregularity is currently carried out, wherein the polylactic acid with high stereoregularity is prepared by ring-opening polymerization of racemic lactide under the catalysis of a catalyst with stereoselectivity, and the polylactic acid has certain performances different from PLLA due to the interaction of poly-L-lactic acid and poly-D-lactic acid with long blocks in a molecular chain, such as melting point 30-60 ℃ higher than that of PLLA, and also has higher mechanical strength. On the other hand, the racemic lactide is used as a polymerization monomer, and the monomer purification process for obtaining the levorotatory lactide with high optical purity is reduced, so that the polylactic acid with high regularity is greatly developed at present. P of the polymer as reported by plum-Shi Bo using CTPB catalyzed ring opening polymerization of racemic lactide m Up to 0.93, and a melting point of 183 ℃ higher than 167 ℃ for PLLA with the same molecular weight (ACS Macro Lett.2018,7, 624-. Wujin utilizes crown ether-assisted metal potassium complex to catalyze ring-opening polymerization of racemic lactide, and P of polymer m Can reach 0.94, and the melting point can reach 192 ℃ (Inorg. chem.2016,55,1, 136-.
While polylactic acid with high stereoregularity is greatly developed, the recycling of waste materials is also concerned based on the principle of sustainable development. Although a series of studies have been reported on depolymerization of polylactic acid, they have focused on depolymerization of PLLA and have not been studied on recycling of polylactic acid having such high stereoregularity. Therefore, a method for rapidly realizing oriented depolymerization of a high-regularity polylactic acid material is needed for a waste high-regularity polylactic acid material.
Disclosure of Invention
The invention provides a magnesium catalyst and a method for depolymerizing polylactic acid with high regularity and recovering racemic lactide by using the same, aiming at solving the problems that the degradation of the existing polylactic acid is mostly PLLA and the degradation of the polylactic acid with high regularity is lacked.
The technical scheme of the invention is as follows:
one of the purposes of the invention is to provide a method for depolymerizing high-regularity polylactic acid, which comprises the following steps: under the conditions of high temperature and vacuum, carrying out catalytic depolymerization on the high-regularity polylactic acid by using a zinc complex catalyst to obtain lactide, wherein Pm of the high-regularity polylactic acid is 0.85-1.0.
Further limited, the zinc complex catalyst is prepared by directly adding 1, 10-phenanthroline and a metal zinc compound into a depolymerization reaction system in situ.
Further limited, the metal zinc compound is zinc chloride or zinc acetate.
Further limit, the adding amount of the zinc complex is 0.01-20 wt% of the high-regularity polylactic acid.
Further limiting, the high temperature is 30-300 ℃.
Further defined, the vacuum condition is 0.001mbar to 100 mbar.
Further limited, the number average molecular weight of the high-regularity polylactic acid is 10 2 g/mol～10 7 g/mol。
Further limiting, the content of the L configuration in the high-regularity polylactic acid is 1-100%.
Further defined, the polymerized units of the highly regular polylactic acid have the following structure:
in the formula, x and y represent the content of L configuration and D configuration in the high-regularity polylactic acid respectively.
Further limited, the proportion of meso-lactide is 2% to 10%.
The invention adopts the zinc complex catalyst prepared by inorganic zinc compound and 1, 10-phenanthroline in situ to catalyze and degrade the polylactic acid with high regularity under the conditions of high temperature and high vacuum degree, thereby realizing the recycling of the waste polylactic acid with the regularity higher than 85%. Compared with the prior art, the application also has the following beneficial effects:
(1) the invention adopts the zinc complex to catalyze the high-regularity polylactic acid, and the catalyst only needs to be prepared in situ in the depolymerization process, so that the production cost is more economic.
(2) The content of L-LA and D-LA in the product obtained by catalytic degradation of polylactic acid depends on the ratio of the two in the high-regularity polylactic acid.
(3) The polylactic acid degraded by the method is high-regularity polylactic acid, fills the blank of catalytic degradation of the high-regularity polylactic acid, and provides more possibility for application of the polylactic acid.
(4) The high-regularity polylactic acid provided by the invention is simple in degradation process and suitable for large-scale production.
Drawings
FIG. 1 is a nuclear magnetic spectrum of a product obtained by depolymerizing high-regularity polylactic acid in example 2.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The experimental procedures used in the following examples are conventional unless otherwise specified. The materials, reagents, methods and apparatus used, unless otherwise specified, are conventional in the art and are commercially available to those skilled in the art.
Example 1:
the reaction process for depolymerizing polylactic acid with tacticity of 99% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottomed flask was charged with 10g of polylactic acid having a tacticity of 99% (Mn 40kg/mol, PDI 1.81, L-LA 50%), and then 95mg of ZnCl 2 And 1, 10-phenanthroline in an equimolar amount, heating to 220 ℃, carrying out reduced pressure distillation reaction for 4 hours under the condition that the pressure is 1mbar, and weighing to obtain a lactide product with the yield of 98% verified by a high performance liquid chromatography and a nuclear magnetic spectrum, wherein the proportion of the racemic lactide is 95% and the proportion of the meso-lactide is 5%.
Example 2:
the reaction process for depolymerizing polylactic acid with tacticity of 99% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottomed flask was charged with 10g of polylactic acid having a tacticity of 99% (Mn 40kg/mol, PDI 1.81, L-LA 50%), and 190mg of ZnCl 2 And equimolar amount of 1, 10-phenanthroline, heated to 220 ℃, and subjected to distillation reaction under reduced pressure at a pressure of 1mbar for 5 hours, to obtain by weighing the product lactide with a yield of 97%, which was verified by high performance liquid chromatography and nuclear magnetic spectrum (as shown in fig. 1), and wherein the proportion of racemic lactide was 91% and the proportion of meso-lactide was 9%.
Example 3:
the reaction process for depolymerizing polylactic acid with tacticity of 99% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottomed flask was charged with 10g of polylactic acid having a tacticity of 99% (Mn 40kg/mol, PDI 1.81, L-LA 50%), followed by addition of 127mg of Zn (OAc) 2 And 1, 10-phenanthroline in an equimolar amount, heating to 220 ℃, carrying out reduced pressure distillation reaction for 4 hours under the condition that the pressure is 1mbar, and weighing to obtain a lactide product with the yield of 96% and verified by high performance liquid chromatography and nuclear magnetic spectrum, wherein the proportion of racemic lactide is 96% and the proportion of meso-lactide is 4%.
Example 4:
the reaction process for depolymerizing polylactic acid with tacticity of 99% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottomed flask was charged with 10g of polylactic acid having a tacticity of 99% (Mn: 40kg/mol, PDI: 1.81, L-LA: 50%), followed by 254mg of Zn (OAc) 2 And 1, 10-phenanthroline in an equimolar amount, heating to 220 ℃, carrying out reduced pressure distillation reaction for 5 hours under the condition that the pressure is 1mbar, and weighing to obtain a lactide product with the yield of 97% verified by a high performance liquid chromatography and a nuclear magnetic spectrum, wherein the proportion of the racemic lactide is 95% and the proportion of the meso-lactide is 5%.
Example 5:
the reaction process for depolymerizing polylactic acid with tacticity of 99% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottomed flask was charged with 10g of polylactic acid having a tacticity of 99% (Mn 40kg/mol, PDI 1.81)L-LA: 99%) and then 95mg of ZnCl are added 2 Heating 1, 10-phenanthroline with equimolar amount, heating to 220 ℃, carrying out reduced pressure distillation reaction for 4 hours under the condition that the pressure is 1mbar, weighing to obtain the product with the yield of 97%, verifying that the product is lactide through high performance liquid chromatography and nuclear magnetic spectrum, wherein the proportion of L-LA is 95%, and the proportion of D-LA is 95%<0.5% and the proportion of meso-lactide is 5%.
Example 6:
the reaction process for depolymerizing polylactic acid with tacticity of 99% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottomed flask was charged with 10g of polylactic acid having a tacticity of 99% (Mn 40kg/mol, PDI 1.81, L-LA: 1%), and then 95mg of ZnCl was added 2 Heating 1, 10-phenanthroline with equimolar amount to 220 deg.C, distilling under reduced pressure at 1mbar for 4 hr, weighing to obtain lactide product with yield of 94% verified by high performance liquid chromatography and nuclear magnetic spectrum, wherein the ratio of L-LA is<0.5%, the proportion of D-LA is 94%, and the proportion of meso-lactide is 6%.
Example 7:
the reaction process for depolymerizing polylactic acid with tacticity of 99% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottomed flask was charged with 10g of polylactic acid having a tacticity of 99% (Mn 40kg/mol, PDI 1.81, L-LA 50%), and then 95mg of ZnCl 2 Heating to 220 deg.C, distilling under reduced pressure at 0.07mbar for 2 hr, weighing to obtain yield of 95%, and verifying by high performance liquid chromatography and nuclear magnetic spectrumThe product is lactide, and the ratio of racemic lactide is 92% and the ratio of meso-lactide is 8%.
Example 8:
the reaction process for depolymerizing polylactic acid with tacticity of 99% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottomed flask was charged with 10g of polylactic acid having a tacticity of 99% (Mn 40kg/mol, PDI 1.81, L-LA 50%), and then 95mg of ZnCl 2 And 1, 10-phenanthroline in an equimolar amount, heating to 180 ℃, and carrying out reduced pressure distillation reaction for 10 hours under the condition that the pressure is 0.07mbar to obtain a product lactide with the yield of 93 percent, which is verified by high performance liquid chromatography and nuclear magnetic spectrum, wherein the proportion of racemic lactide is 93 percent, and the proportion of meso-lactide is 7 percent.
Example 9:
the reaction process for depolymerizing polylactic acid with tacticity of 99% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottomed flask was charged with 10g of polylactic acid having a tacticity of 99% (Mn 40kg/mol, PDI 1.81, L-LA 50%), and then 95mg of ZnCl 2 And 1, 10-phenanthroline in an equimolar amount, heating to 250 ℃, carrying out reduced pressure distillation reaction for 1h under the condition that the pressure is 0.07mbar, and weighing to obtain a lactide product with the yield of 96% verified by high performance liquid chromatography and nuclear magnetic spectrum, wherein the proportion of the racemic lactide is 90% and the proportion of the meso-lactide is 10%.
Example 10:
the reaction process of the polylactic acid with depolymerization regularity of 95% in this example is as follows:
the experimental process comprises the following steps:
a25 mL round-bottom flask was charged with 10g of 95% polylactic acid (Mn: 40kg/mol, PDI: 1.81, L-LA: 50%), and then 95mg of ZnCl 2 And 1, 10-phenanthroline in an equimolar amount, heating to 220 ℃, carrying out reduced pressure distillation reaction for 1.8h under the condition that the pressure is 0.07mbar, and weighing to obtain the product lactide with the yield of 95% verified by high performance liquid chromatography and nuclear magnetic spectrum, wherein the proportion of racemic lactide is 92% and the proportion of meso-lactide is 8%.
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (10)
1. A method for depolymerizing high-regularity polylactic acid is characterized in that the high-regularity polylactic acid is catalytically depolymerized by using a zinc complex catalyst under the conditions of high temperature and vacuum to obtain lactide, wherein Pm of the high-regularity polylactic acid is 0.85-1.0.
2. The method for depolymerizing highly regular polylactic acid according to claim 1, wherein the zinc complex catalyst is prepared in situ by directly adding 1, 10-phenanthroline and a zinc metal compound to the depolymerization reaction system.
3. The method for depolymerizing highly regular polylactic acid according to claim 2, wherein the metallic zinc compound is zinc chloride or zinc acetate.
4. The method for depolymerizing highly regular polylactic acid according to claim 1, wherein the amount of the zinc complex added is 0.01 to 20 wt% based on the highly regular polylactic acid.
5. The method for depolymerizing highly regular polylactic acid according to claim 1, wherein the high temperature is 30 ℃ to 300 ℃.
6. The method for depolymerizing highly regular polylactic acid according to claim 1, wherein the vacuum condition is 0.001 to 100 mbar.
7. The method for depolymerizing highly regular polylactic acid according to claim 1, wherein the highly regular polylactic acid has a number average molecular weight of 10 2 ～10 7 g/mol。
8. The method for depolymerizing highly regular polylactic acid according to claim 1, wherein the content of L configuration in the highly regular polylactic acid is 1 to 100%.
9. The method for depolymerizing highly regular polylactic acid according to claim 1, wherein the polymerized units of the highly regular polylactic acid have the following structure:
in the formula, x and y represent the content of L configuration and D configuration in the high-regularity polylactic acid respectively.
10. Lactide obtained by the process according to claim 1, characterized in that the proportion of meso-lactide is 2 to 10%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210890799.0A CN115073418B (en) | 2022-07-27 | 2022-07-27 | Zinc complex catalyst and method for depolymerizing high-regularity polylactic acid and recycling racemic lactide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210890799.0A CN115073418B (en) | 2022-07-27 | 2022-07-27 | Zinc complex catalyst and method for depolymerizing high-regularity polylactic acid and recycling racemic lactide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115073418A true CN115073418A (en) | 2022-09-20 |
| CN115073418B CN115073418B (en) | 2024-01-26 |
Family
ID=83242365
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210890799.0A Active CN115073418B (en) | 2022-07-27 | 2022-07-27 | Zinc complex catalyst and method for depolymerizing high-regularity polylactic acid and recycling racemic lactide |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115073418B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116444388A (en) * | 2023-03-09 | 2023-07-18 | 中国科学院青岛生物能源与过程研究所 | Method for preparing morpholine-2, 5-dione monomer by polylactic acid ammonolysis |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1594313A (en) * | 2004-07-13 | 2005-03-16 | 武汉大学 | Process for continuous preparation of lactide |
| CN102766132A (en) * | 2012-08-14 | 2012-11-07 | 北京普利玛科技有限责任公司 | Method for preparing lactide continuously |
| US20150065732A1 (en) * | 2012-06-29 | 2015-03-05 | Xiaogan Esun New Material Co., Ltd. | Method for preparing refined lactide from recovered polylactic acid |
| CN109400574A (en) * | 2018-12-13 | 2019-03-01 | 中国科学院长春应用化学研究所 | A kind of method of purification and application of thick lactide |
| CN113150375A (en) * | 2021-03-29 | 2021-07-23 | 中国科学院青岛生物能源与过程研究所 | Method for recycling polylactic acid material under catalysis of zinc catalyst |
| CN113582965A (en) * | 2021-08-23 | 2021-11-02 | 扬州惠通科技股份有限公司 | Method for preparing high-purity lactide based on catalytic cracking of organic guanidine complex |
| CN114591167A (en) * | 2022-03-11 | 2022-06-07 | 中国科学院青岛生物能源与过程研究所 | Method for recycling polylactic acid mixed plastic |
-
2022
- 2022-07-27 CN CN202210890799.0A patent/CN115073418B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1594313A (en) * | 2004-07-13 | 2005-03-16 | 武汉大学 | Process for continuous preparation of lactide |
| US20150065732A1 (en) * | 2012-06-29 | 2015-03-05 | Xiaogan Esun New Material Co., Ltd. | Method for preparing refined lactide from recovered polylactic acid |
| CN102766132A (en) * | 2012-08-14 | 2012-11-07 | 北京普利玛科技有限责任公司 | Method for preparing lactide continuously |
| CN109400574A (en) * | 2018-12-13 | 2019-03-01 | 中国科学院长春应用化学研究所 | A kind of method of purification and application of thick lactide |
| CN113150375A (en) * | 2021-03-29 | 2021-07-23 | 中国科学院青岛生物能源与过程研究所 | Method for recycling polylactic acid material under catalysis of zinc catalyst |
| CN113582965A (en) * | 2021-08-23 | 2021-11-02 | 扬州惠通科技股份有限公司 | Method for preparing high-purity lactide based on catalytic cracking of organic guanidine complex |
| CN114591167A (en) * | 2022-03-11 | 2022-06-07 | 中国科学院青岛生物能源与过程研究所 | Method for recycling polylactic acid mixed plastic |
Non-Patent Citations (1)
| Title |
|---|
| GUAN-JHEN CHEN ET AL: "Synthesis of zinc complexes bearing pyridine derivatives and their application of ε-caprolactone and L-Lactide polymerization", POLYMER, vol. 194, pages 122374 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116444388A (en) * | 2023-03-09 | 2023-07-18 | 中国科学院青岛生物能源与过程研究所 | Method for preparing morpholine-2, 5-dione monomer by polylactic acid ammonolysis |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115073418B (en) | 2024-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Tang et al. | Toward infinitely recyclable plastics derived from renewable cyclic esters | |
| Shi et al. | Hybrid monomer design for unifying conflicting polymerizability, recyclability, and performance properties | |
| Yang et al. | A “Polymer to Polymer” chemical recycling of PLA plastics by the “DE–RE Polymerization” strategy | |
| Hu et al. | Efficient ZnO aqueous nanoparticle catalysed lactide synthesis for poly (lactic acid) fibre production from food waste | |
| Zhang et al. | Efficient synthesis of lactide with low racemization catalyzed by sodium bicarbonate and zinc lactate | |
| JP4048764B2 (en) | Method for producing lactide using fermented lactic acid as raw material and method for producing polylactic acid | |
| CN115073418A (en) | Magnesium catalyst and method for recovering racemic lactide by depolymerizing high-regularity polylactic acid by using same | |
| KR101230907B1 (en) | Manufacturing Method of Lactide from Lactic acid | |
| CN114685423B (en) | Method for synthesizing lactide from L-lactic acid by adopting fixed bed reactor | |
| JP5678663B2 (en) | Method for producing 2-hydroxyisobutyric acid polymer and depolymerization method | |
| KR101326524B1 (en) | Manufacturing method of lactide synthesis from lactic acid | |
| CN115160288A (en) | Method for recovering meso-lactide by catalytic degradation of polylactic acid | |
| CN114031600B (en) | Method for recycling caprolactone from poly epsilon-caprolactone waste | |
| CN115141364B (en) | Zinc catalyst and method for catalyzing recycling polylactic acid material by zinc catalyst | |
| CN111777508A (en) | Method for recovering glycollate | |
| JP2007224113A (en) | Method for recovering effective components from recovered biodegradable polyester | |
| KR101326521B1 (en) | Manufacturing Method of Lactide from Lactic acid | |
| CN115160289B (en) | Magnesium catalyst and method for depolymerizing random polylactic acid and recycling lactide by using magnesium catalyst | |
| CN112010834B (en) | Method for synthesizing glycolide in one step | |
| US20120245322A1 (en) | Manufacturing lactide from lactic acid | |
| CN115160287B (en) | Zinc catalyst and method for depolymerizing polylactic acid stereocomplex and recycling racemic lactide | |
| KR101327892B1 (en) | Method for preparing lactide from alkyl lactate | |
| CN116396248B (en) | Method for depolymerizing polyester into cyclic lactone | |
| CN114797971B (en) | Organic base catalyst and method for catalyzing polycaprolactone alcoholysis by using same | |
| Wang et al. | Recent advances in the chemical recycling of polyesters |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |