CN117550969A - Method for catalyzing waste polylactic acid alcoholysis by metal-free acetic acid dicycloguanidine salt - Google Patents
Method for catalyzing waste polylactic acid alcoholysis by metal-free acetic acid dicycloguanidine salt Download PDFInfo
- Publication number
- CN117550969A CN117550969A CN202311493592.0A CN202311493592A CN117550969A CN 117550969 A CN117550969 A CN 117550969A CN 202311493592 A CN202311493592 A CN 202311493592A CN 117550969 A CN117550969 A CN 117550969A
- Authority
- CN
- China
- Prior art keywords
- polylactic acid
- acetate
- reaction
- pla
- waste
- 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.)
- Pending
Links
- 239000004626 polylactic acid Substances 0.000 title claims abstract description 109
- 229920000747 poly(lactic acid) Polymers 0.000 title claims abstract description 108
- 239000002699 waste material Substances 0.000 title claims abstract description 34
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000006136 alcoholysis reaction Methods 0.000 title claims abstract description 21
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 title claims description 30
- 150000003839 salts Chemical class 0.000 title abstract description 4
- 238000006243 chemical reaction Methods 0.000 claims abstract description 88
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 claims abstract description 34
- 239000003054 catalyst Substances 0.000 claims abstract description 24
- 150000002357 guanidines Chemical class 0.000 claims abstract description 16
- JVTAAEKCZFNVCJ-UHFFFAOYSA-M Lactate Chemical compound CC(O)C([O-])=O JVTAAEKCZFNVCJ-UHFFFAOYSA-M 0.000 claims abstract description 10
- WVDDGKGOMKODPV-UHFFFAOYSA-N Benzyl alcohol Chemical compound OCC1=CC=CC=C1 WVDDGKGOMKODPV-UHFFFAOYSA-N 0.000 claims description 24
- DXTIKTAIYCJTII-UHFFFAOYSA-N guanidine acetate Chemical compound CC([O-])=O.NC([NH3+])=N DXTIKTAIYCJTII-UHFFFAOYSA-N 0.000 claims description 20
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 15
- 238000006731 degradation reaction Methods 0.000 claims description 10
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 9
- 235000019445 benzyl alcohol Nutrition 0.000 claims description 8
- 239000000047 product Substances 0.000 claims description 7
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 claims description 6
- LQZZUXJYWNFBMV-UHFFFAOYSA-N dodecan-1-ol Chemical compound CCCCCCCCCCCCO LQZZUXJYWNFBMV-UHFFFAOYSA-N 0.000 claims description 6
- PHTQWCKDNZKARW-UHFFFAOYSA-N isoamylol Chemical compound CC(C)CCO PHTQWCKDNZKARW-UHFFFAOYSA-N 0.000 claims description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
- 238000011084 recovery Methods 0.000 claims description 5
- 239000002904 solvent Substances 0.000 claims description 4
- BWDBEAQIHAEVLV-UHFFFAOYSA-N 6-methylheptan-1-ol Chemical compound CC(C)CCCCCO BWDBEAQIHAEVLV-UHFFFAOYSA-N 0.000 claims description 3
- 230000001476 alcoholic effect Effects 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 3
- 239000000706 filtrate Substances 0.000 claims description 3
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 claims description 3
- 238000010146 3D printing Methods 0.000 claims description 2
- 239000000463 material Substances 0.000 claims description 2
- 238000004806 packaging method and process Methods 0.000 claims description 2
- 230000035484 reaction time Effects 0.000 claims description 2
- 239000010902 straw Substances 0.000 claims description 2
- JHYKJJIJPWNOME-UHFFFAOYSA-N 1,4a,8-triazido-2,3,4,5,6,7-hexahydro-1H-naphthalene Chemical compound N(=[N+]=[N-])C12CCCC(=C2C(CCC1)N=[N+]=[N-])N=[N+]=[N-] JHYKJJIJPWNOME-UHFFFAOYSA-N 0.000 claims 1
- 238000001914 filtration Methods 0.000 claims 1
- 239000002184 metal Substances 0.000 abstract description 7
- 238000004064 recycling Methods 0.000 abstract description 7
- 230000008901 benefit Effects 0.000 abstract description 5
- 230000003197 catalytic effect Effects 0.000 abstract description 4
- ZYTLPUIDJRKAAM-UHFFFAOYSA-N benzyl 2-hydroxypropanoate Chemical compound CC(O)C(=O)OCC1=CC=CC=C1 ZYTLPUIDJRKAAM-UHFFFAOYSA-N 0.000 description 33
- 239000000243 solution Substances 0.000 description 29
- 239000007789 gas Substances 0.000 description 23
- 239000007795 chemical reaction product Substances 0.000 description 22
- 238000010812 external standard method Methods 0.000 description 21
- WVDDGKGOMKODPV-ZQBYOMGUSA-N phenyl(114C)methanol Chemical compound O[14CH2]C1=CC=CC=C1 WVDDGKGOMKODPV-ZQBYOMGUSA-N 0.000 description 13
- 238000003756 stirring Methods 0.000 description 13
- 150000007530 organic bases Chemical class 0.000 description 7
- 238000003760 magnetic stirring Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 238000002411 thermogravimetry Methods 0.000 description 5
- 238000000113 differential scanning calorimetry Methods 0.000 description 4
- LZCLXQDLBQLTDK-UHFFFAOYSA-N ethyl 2-hydroxypropanoate Chemical compound CCOC(=O)C(C)O LZCLXQDLBQLTDK-UHFFFAOYSA-N 0.000 description 4
- 238000001757 thermogravimetry curve Methods 0.000 description 3
- CRORGGSWAKIXSA-UHFFFAOYSA-N 3-methylbutyl 2-hydroxypropanoate Chemical compound CC(C)CCOC(=O)C(C)O CRORGGSWAKIXSA-UHFFFAOYSA-N 0.000 description 2
- IYYWOACCVUDHMK-UHFFFAOYSA-N 6-methylheptyl 2-hydroxypropanoate Chemical compound CC(C)CCCCCOC(=O)C(C)O IYYWOACCVUDHMK-UHFFFAOYSA-N 0.000 description 2
- LPEKGGXMPWTOCB-UHFFFAOYSA-N 8beta-(2,3-epoxy-2-methylbutyryloxy)-14-acetoxytithifolin Natural products COC(=O)C(C)O LPEKGGXMPWTOCB-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- MRABAEUHTLLEML-UHFFFAOYSA-N Butyl lactate Chemical compound CCCCOC(=O)C(C)O MRABAEUHTLLEML-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 238000005481 NMR spectroscopy Methods 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000001191 butyl (2R)-2-hydroxypropanoate Substances 0.000 description 2
- 239000012295 chemical reaction liquid Substances 0.000 description 2
- UURSXESKOOOTOV-UHFFFAOYSA-N dec-5-ene Chemical compound CCCCC=CCCCC UURSXESKOOOTOV-UHFFFAOYSA-N 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 238000001938 differential scanning calorimetry curve Methods 0.000 description 2
- QQQMUBLXDAFBRH-UHFFFAOYSA-N dodecyl 2-hydroxypropanoate Chemical compound CCCCCCCCCCCCOC(=O)C(C)O QQQMUBLXDAFBRH-UHFFFAOYSA-N 0.000 description 2
- ODQWQRRAPPTVAG-GZTJUZNOSA-N doxepin Chemical compound C1OC2=CC=CC=C2C(=C/CCN(C)C)/C2=CC=CC=C21 ODQWQRRAPPTVAG-GZTJUZNOSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229940116333 ethyl lactate Drugs 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 239000012847 fine chemical Substances 0.000 description 2
- 238000004817 gas chromatography Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 150000003903 lactic acid esters Chemical class 0.000 description 2
- 238000001819 mass spectrum Methods 0.000 description 2
- 229940057867 methyl lactate Drugs 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- ILVGAIQLOCKNQA-UHFFFAOYSA-N propyl 2-hydroxypropanoate Chemical compound CCCOC(=O)C(C)O ILVGAIQLOCKNQA-UHFFFAOYSA-N 0.000 description 2
- 239000012265 solid product Substances 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 208000034530 PLAA-associated neurodevelopmental disease Diseases 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229920000704 biodegradable plastic Polymers 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 238000012993 chemical processing Methods 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 239000012459 cleaning agent Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000002608 ionic liquid Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 231100000053 low toxicity Toxicity 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 238000006303 photolysis reaction Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000002390 rotary evaporation Methods 0.000 description 1
- 235000013599 spices Nutrition 0.000 description 1
- 238000000967 suction filtration Methods 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- 238000003828 vacuum filtration Methods 0.000 description 1
- 230000002792 vascular Effects 0.000 description 1
- 238000003809 water extraction Methods 0.000 description 1
Abstract
The invention discloses a method for efficiently catalyzing waste polylactic acid alcoholysis by metal-free acetate dicyclo guanidine salt. The catalyst used in the invention is metal-free acetate dicycloguanidine salt, has high catalytic activity on the alcoholysis reaction of waste polylactic acid, can degrade 100% of waste polylactic acid under certain conditions and obtain lactate with high yield (the yield range is 91.4% -95.6%), thereby realizing the upgrading and recycling of waste PLA. Meanwhile, the catalyst has strong thermal stability, is not easy to decompose at high temperature, and can be recycled. The method solves the problems of low reaction rate, low yield, metal residue in the product and the like in the process of alcoholysis of waste PLA, and the catalyst has the advantages of green, no pollution, recycling and the like.
Description
Technical Field
The invention belongs to the field of metal-free green catalysis and chemical recovery of biodegradable plastics; in particular to a method for catalyzing the alcoholysis of waste polylactic acid by acetate dicyclo guanidine salt.
Background
Polylactic acid (PLA) has good biodegradability, easy processing and biocompatibility, and is widely applied to the fields of disposable packaging materials, medicine slow release, vascular stents and the like. In recent years, the waste amount of polylactic acid has increased dramatically, and finding a suitable method for recycling waste PLA has become a research hotspot at the present stage. Degrading waste PLA into high value-added chemicals by a chemical method is an effective way for recycling the waste PLA at present. Chemical recovery of PLA mainly includes hydrolysis, photodecomposition, pyrolysis, alcoholysis, and the like. The alcoholysis method has the advantages of mild reaction conditions, contribution to industrial operation and the like, and can degrade the waste polylactic acid into corresponding lactate so as to increase the economic benefit of recycling the waste polylactic acid. Lactic acid esters are an important chemical, and are widely applied to industries such as paint, spice synthesis, resin, adhesive, production of cleaning agents for precision electronic components, fine chemical processing and the like.
At present, the common catalyst in the PLA alcoholysis process is a metal catalyst, a complex thereof, an ionic liquid and other metal-containing compounds, so that the problem of metal residue exists in the use process, the purification difficulty of the product lactate is increased, and the application of the lactate in some fine chemical industry is limited. The metal-free catalyst has the advantages of environmental protection, low toxicity and the like, and is getting more attention in the application of catalyzing PLA alcoholysis, but the problems of low catalyst activity, poor stability and the like are also existed.
Disclosure of Invention
The invention aims to: aiming at the problems of low reaction rate, low lactate yield, metal residue in products and the like in the waste polylactic acid alcoholysis process in the prior art, a method for catalyzing the waste polylactic acid alcoholysis by acetate dicyclo guanidine salt is designed and developed so as to increase the reaction rate and improve the reaction conditions.
In order to achieve the above purpose, the specific technical scheme provided is as follows:
a method for catalyzing alcoholysis of polylactic acid by acetate dicyclo guanidine salt relates to application of acetate dicyclo guanidine salt in alcoholysis of waste polylactic acid.
Specifically, alcohol is used as a solvent, and the acetate bicyclo guanidine salt catalyst and the waste polylactic acid are subjected to degradation reaction to obtain the corresponding lactate.
The reaction equation is as follows:
wherein the alcohol is any one of methanol, ethanol, propanol, butanol, isoamyl alcohol, isooctyl alcohol, n-dodecyl alcohol or benzyl alcohol.
The polylactic acid comprises, but is not limited to, waste polylactic acid, and the waste polylactic acid is any one or a combination of a plurality of waste polylactic acid packaging bags, waste polylactic acid straws and waste polylactic acid 3D printing materials.
Wherein the acetic acid dicyclo guanidine salt is obtained by reacting 1,5, 7-triazidine (4.4.0) dec-5-ene (organic base TBD) with acetic acid according to a molar ratio of 1:1.
Wherein the mass ratio of the acetic acid dicyclo guanidine salt catalyst to the PLA is 1:40-1:10, preferably 1:20-3:40.
Wherein the mass ratio of the alcohol to the waste polylactic acid is 5:1-12.5:1, preferably 7.5:1-10:1.
Wherein the degradation reaction condition is normal pressure, and the reaction temperature is 140-200 ℃, preferably 160-200 ℃.
Wherein the degradation reaction time is 0.5 h-3 h, preferably 2 h-3 h.
And after the degradation reaction is finished, catalyst recovery treatment is carried out. The catalyst is recovered, the degradation reaction liquid is subjected to vacuum filtration and extraction, the filtrate is subjected to water extraction, the extract liquid is a solution containing acetate dicyclo guanidine salt, the water is removed by evaporation, and the acetate dicyclo guanidine salt or an alcohol solution of the acetate dicyclo guanidine salt is recovered; the raffinate is an alcoholic solution containing lactate.
The obtained dicycloguanidine acetate or the alcohol solution of dicycloguanidine acetate is recycled as a catalyst, has excellent recycling performance, and the catalytic activity is not obviously reduced after the dicycloguanidine acetate or the alcohol solution is repeatedly used for 5 times.
Wherein the conversion of PLA and the yield of lactate are calculated according to the formulas (1) and (2), respectively
The beneficial effects are that:
according to the invention, dicyclo guanidine acetate is used as a catalyst, and waste polylactic acid is subjected to alcoholysis to generate lactate. The catalyst has high catalytic activity and high thermal stability, and can obtain lactic acid ester with higher yield under certain conditions; the dicyclo guanidine acetate does not contain metal, has high stability, can effectively solve the problem of metal residue in the product, can recycle the catalyst, provides a new process method for alcoholysis recycling of waste PLA, and has excellent industrial application prospect.
Drawings
The foregoing and/or other advantages of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings and detailed description.
FIG. 1 is a comparison of DSC heating curves (a) and TGA curves (b) of catalyst acetate bicyclo guanidine salt (HTBD-OAc) and TBD in the present invention.
FIG. 2 shows a nuclear magnetic resonance hydrogen spectrum of benzyl lactate as a product using benzyl alcohol as a solvent.
FIG. 3 is a graph comparing the gas chromatography (a) and mass spectrum (b) of benzyl lactate standard with the main product of polylactic acid formation catalyzed by dicycloguanidine acetate in benzyl alcohol as solvent.
Detailed Description
The invention is illustrated below with reference to specific examples.
The gas chromatographic methods described in the following examples were:
the yield of PLA reaction products was determined using a GC 2010plus gas chromatograph from shimadzu (Shanghai) commercial company. The column temperature is 100 ℃, the temperature is increased to 280 ℃ at the speed of 10 ℃/min, and N 2 As a protective atmosphere, the carrier gas flow is 3ml/min for split sample injection, and the sample injection amount is 1 mu L.
Example 1
5g of organic base 1,5, 7-triazidine bicyclo (4.4.0) dec-5-ene (TBD) is dissolved in deionized water, then acetic acid aqueous solution with the concentration of 4% is added into the TBD aqueous solution through a constant pressure dropping funnel, the mol ratio of TBD to acetic acid is controlled to be 1:1, and the target product is obtained after stirring reaction for 12 hours at the temperature of 30 ℃. After water in the solution is removed by rotary evaporation, the solid product is placed into a vacuum drying oven to be dried for 48 hours, and the white solid product is the dicyclo guanidine acetate, and the weight is 6.8g, and the yield is 95.1%. Differential Scanning Calorimetry (DSC) analysis and thermogravimetric analysis (TGA) were performed on dicycloguanidine acetate (HTBD-OAc) and organic base (TBD).
The DSC method comprises the following steps: two increases in temperature were taken under nitrogen using a DSC model Q20 (TA Instruments, USA). The first heating is carried out at a speed of 10 ℃ per minute from 40 ℃ to 220 ℃, the temperature stays at a high temperature for 1min, the temperature is reduced at a speed of 10 ℃ per minute from 220 ℃ to 40 ℃, the temperature stays at a low temperature for 1min, and the second heating is carried out at a speed of 10 ℃ per minute from 40 ℃ to 220 ℃, and the temperature stays at a high temperature for 1min.
The TGA method comprises the following steps: thermogravimetric analysis was used to determine the thermal decomposition of the catalyst using model TGA Q550, the sample was heated from 25 ℃ to 600 ℃ at a rate of 10 ℃/min under nitrogen atmosphere.
DSC heating curves (a) and TGA curves (b) of dicycloguanidine acetate (HTBD-OAc) and organic base (TBD) are shown in FIG. 1. DSC results show that the melting point of HTBD-OAc is raised to 155℃in comparison with TBD. The TGA profile shows that HTBD-OAc is more thermally stable than TBD and begins to lose weight significantly at about 200 c, indicating that HTBD-OAc can be stably present in the alcoholysis reaction.
Example 2
To a 50mL magnetic stirring autoclave was added 1g PLA,7.5g methanol, 50mg dicyclo guanidine acetate (prepared in example 1). After the reaction was completed, the reaction solution was cooled to room temperature and filtered under reduced pressure for 2 hours at 160℃to separate unreacted PLA residues, and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product methyl lactate was quantitatively analyzed in a gas chromatograph by an external standard method, and the yield of methyl lactate was analyzed to be 95.6%.
Example 3
To a 50mL magnetic stirring autoclave was added 1g PLA,7.5g ethanol, 50mg dicycloguanidine acetate (prepared in example 1). After the reaction was completed, the reaction solution was cooled to room temperature and filtered under reduced pressure for 2 hours at 160℃to separate unreacted PLA residues, and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product ethyl lactate was quantitatively analyzed in a gas chromatograph by an external standard method, and the yield of ethyl lactate was 94.4%.
Example 4
To a 50mL magnetic stirring autoclave was added 1g PLA,7.5g propanol, 50mg dicyclo guanidine acetate (prepared in example 1). After the reaction was completed, the reaction solution was cooled to room temperature and filtered under reduced pressure for 2 hours at 160℃to separate unreacted PLA residues, and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product propyl lactate was quantitatively analyzed in a gas chromatograph by an external standard method, and the yield of propyl lactate was 93.1%.
Example 5
To a 50mL magnetic stirring autoclave was added 1g PLA,7.5g butanol, 50mg dicyclo guanidine acetate (prepared in example 1). After the reaction was completed, the reaction solution was cooled to room temperature and filtered under reduced pressure for 2 hours at 160℃to separate unreacted PLA residues, and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product butyl lactate was quantitatively analyzed in a gas chromatograph by an external standard method, and the yield of butyl lactate was found to be 92.9%.
Example 6
To a 50mL magnetic stirring autoclave was added 1g PLA,7.5g isoamyl alcohol, 50mg dicycloguanidine acetate (prepared in example 1). The reaction was carried out at 160℃for 3h, after which the reaction mixture was cooled to room temperature and filtered under reduced pressure to separate the unreacted PLA residue, which was dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product of isoamyl lactate was quantitatively analyzed in a gas chromatograph by an external standard method to give an isoamyl lactate yield of 92.3%.
Example 7
To a 50mL single neck flask was added 1g of PLA,7.5g of isooctanol, 50mg of dicycloguanidine acetate (prepared in example 1), and the mixture was placed in an oil bath at 160℃and reacted for 3 hours with continuous stirring. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The isooctyl lactate as a reaction product was quantitatively analyzed in a gas chromatograph by an external standard method to give a yield of 91.8% isooctyl lactate.
Example 8
To a 50mL one-neck flask, 1g of PLA,7.5g of n-dodecanol, 50mg of dicycloguanidine acetate (prepared in example 1) were charged, and the reaction was continued in an oil bath at 180℃with stirring for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product lauryl lactate is quantitatively analyzed in a gas chromatograph by an external standard method, and the yield of the lauryl lactate is 93.2 percent.
Example 9
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 50mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 180℃with stirring for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was analyzed to be 94.4%. The nuclear magnetic resonance hydrogen spectrum of benzyl lactate is shown in fig. 2, the gas chromatography is shown in fig. 3 (a), and the mass spectrum is shown in fig. 3 (b).
Example 10
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 50mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 140℃with stirring for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 71.2%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was analyzed to be 57.8%.
Example 11
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 50mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 160℃with stirring for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 93.4%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was analyzed to be 90.6%.
Example 12
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 50mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 200℃with stirring for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph by an external standard method to give a benzyl lactate yield of 91.4%.
Example 13
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 50mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was stirred continuously in an oil bath at 180℃for 0.5h. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 68.7%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was analyzed to be 62.5%.
Example 14
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 50mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 180℃with stirring for 1 hour. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 88.4%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph by an external standard method to yield 85.2% benzyl lactate.
Example 15
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 50mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 180℃with stirring for 3 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was analyzed to be 92.8%.
Example 16
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 25mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 180℃with stirring for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 85.5%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was analyzed to be 79.1%.
Example 17
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 75mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 180℃with stirring for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was analyzed to be 92.9%.
Example 18
To a 50mL one-neck flask, 1g of PLA,7.5g of benzyl alcohol, 100mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 180℃with stirring for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was found to be 92.6%.
Example 19
To a 50mL one-neck flask, 1g of PLA,5g of benzyl alcohol, 50mg of dicycloguanidine acetate (prepared in example 1) were added, and the reaction was stirred continuously in an oil bath at 180℃for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 93.6%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was analyzed to be 89.4%.
Example 20
To a 50mL one-neck flask, 1g of PLA,10g of benzyl alcohol, 50mg of dicycloguanidine acetate (prepared in example 1) were added, and the reaction was stirred continuously in an oil bath at 180℃for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was found to be 93.1%.
Example 21
To a 50mL one-neck flask, 1g of PLA,12.5g of benzyl alcohol, 50mg of dicyclo guanidine acetate (prepared in example 1) were added, and the reaction was continued in an oil bath at 180℃with stirring for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under this condition, the conversion of PLA was 100%. The reaction product benzyl lactate was quantitatively analyzed in a gas chromatograph using an external standard method, and the yield of benzyl lactate was analyzed to be 92.4%.
Example 22
The regeneration performance of the catalyst is evaluated through a catalyst circulation experiment, and the catalyst is specifically operated to obtain PLA residues through decompression and suction filtration of degradation reaction liquid, adding deionized water for extraction, taking supernatant, evaporating to dryness, and drying in a vacuum oven at 60 ℃ for 12 hours to obtain benzyl alcohol solution of the dicycloguanidine acetate. Fresh benzyl alcohol solution was replenished to the total mass of benzyl alcohol and dicycloguanidine acetate as required in example 9, and 1g of PLA pellets were added for the experiment. After the operation is repeated for 5 times, the activity of the dicyclo guanidine acetate is still high, and the yield of the benzyl lactate is 92%.
Comparative example 1
In 2 single-necked flasks of 50mL, the same molar amount of dicycloguanidine acetate and TBD as organic base were charged, and the reaction was carried out for 2 hours under the reaction conditions of example 9. After the reaction, the reaction solution was cooled to room temperature and suction-filtered under reduced pressure, and unreacted PLA residues were separated and dried to constant weight in a vacuum oven. Under the condition, the conversion rate of the acetic acid dicycloguanidine salt and the organic base TBD catalyzed PLA benzyl alcohol alcoholysis is 100 percent. The reaction product benzyl lactate is quantitatively analyzed in a gas chromatograph by an external standard method, and the yield of the benzyl lactate catalyzed by the dicycloguanidine acetate to PLA alcoholysis is 94.1 percent, and the yield of the benzyl lactate catalyzed by the organic base TBD is 86.2 percent. It is seen that the catalytic activity of the dicycloguanidine acetate is higher.
The invention provides a method for catalyzing waste polylactic acid alcoholysis by acetic acid dicyclo guanidine salt. There are many ways of implementing this solution, the above description is only a preferred embodiment of the present invention, and it should be pointed out that, for a person skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The components not explicitly described in this embodiment can be implemented by using the prior art.
Claims (10)
1. A method for catalyzing the alcoholysis of waste polylactic acid by acetate bicyclo guanidine salt is characterized in that alcohol is used as a solvent, and the catalyst acetate bicyclo guanidine salt and polylactic acid are mixed and then subjected to degradation reaction to obtain the product lactate.
2. The method of claim 1, wherein the waste polylactic acid is any one or a combination of a waste polylactic acid packaging bag, a waste polylactic acid straw and a waste polylactic acid 3D printing material.
3. The method of claim 1, wherein the alcohol is any one of methanol, ethanol, propanol, butanol, isoamyl alcohol, isooctyl alcohol, n-dodecyl alcohol, or benzyl alcohol.
4. The method according to claim 1, wherein the mass ratio of the alcohol to the waste polylactic acid is 5:1 to 12.5:1.
5. The method of claim 1, wherein the acetate bicyclo guanidine salt is obtained by reacting 1,5, 7-triazido bicyclo (4.4.0) dec-5-ene with acetic acid in a molar ratio of 1:1.
6. The method according to claim 1, wherein the mass ratio of the dicycloguanidine acetate catalyst to the waste polylactic acid is 1:40-1:10.
7. The method according to claim 1, wherein the degradation reaction condition is normal pressure, the reaction temperature is 140 ℃ to 200 ℃, and the reaction time is 0.5h to 3h.
8. The method according to claim 1, wherein the catalyst recovery treatment is performed after the degradation reaction is completed.
9. The method of claim 8, wherein the recovery process comprises vacuum filtering the degradation reaction solution to obtain a filtrate, extracting the filtrate with water, evaporating the extractive solution to remove water, and recovering to obtain the dicyclo guanidine acetate or the alcoholic solution of dicyclo guanidine acetate.
10. The method according to claim 9, wherein the recovered alcoholic solution of dicycloguanidine acetate or dicycloguanidine acetate is recycled as a catalyst.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311493592.0A CN117550969A (en) | 2023-11-10 | 2023-11-10 | Method for catalyzing waste polylactic acid alcoholysis by metal-free acetic acid dicycloguanidine salt |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311493592.0A CN117550969A (en) | 2023-11-10 | 2023-11-10 | Method for catalyzing waste polylactic acid alcoholysis by metal-free acetic acid dicycloguanidine salt |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117550969A true CN117550969A (en) | 2024-02-13 |
Family
ID=89815811
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311493592.0A Pending CN117550969A (en) | 2023-11-10 | 2023-11-10 | Method for catalyzing waste polylactic acid alcoholysis by metal-free acetic acid dicycloguanidine salt |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117550969A (en) |
-
2023
- 2023-11-10 CN CN202311493592.0A patent/CN117550969A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9561492B2 (en) | Method for producing lactide directly from lactic acid and a catalyst used therein | |
| WO2018176884A1 (en) | Method for producing optically pure l-/d-lactide with all-green closed cycle process | |
| CN102659590B (en) | Alcoholysis recovery method of waster polylactic acid in ionic liquid environment | |
| TWI414512B (en) | Process for preparing alpha-hydroxycarboxylic esters | |
| EP4183823A1 (en) | Depolymerization catalyst of polymer comprising ester functional group, and depolymerization method using same | |
| KR101396007B1 (en) | Process for preparing tetramethyl glycolide | |
| CN117550969A (en) | Method for catalyzing waste polylactic acid alcoholysis by metal-free acetic acid dicycloguanidine salt | |
| CN102285957B (en) | Method for preparing glycerol carbonate | |
| CN101434539B (en) | Preparation of benzyl acetate | |
| CN102476978B (en) | Novel synthetic method preparing alkynol compound from acetylene | |
| CN104710402A (en) | Dicyclohexyl crown ether synthesis method | |
| CN111848570A (en) | Hexaacyl reductive cercospora bacteriocin photocatalyst and preparation and application thereof | |
| CN110536880B (en) | Process for producing indanecarbaldehyde | |
| CN107721936B (en) | Method for aqueous phase synthesis of 3, 4-dihydropyrimidine-2-ketone compounds | |
| CN111217694B (en) | Method for selectively reducing carbon-carbon double bond in alpha, beta-unsaturated carbonyl compound | |
| EP2842932A1 (en) | Method for continuously producing high-content high-optical-purity lactate | |
| CN113087625B (en) | Method for synthesizing benzyl acetate by utilizing combined catalytic system | |
| CN110028466B (en) | Method for producing dimorpholinyl diethyl ether | |
| CN108484484B (en) | Preparation method of 2-oxo-3-ethyl piperidinecarboxylate | |
| JPH05500952A (en) | Method for producing dihydroxy ester | |
| CN103145538A (en) | Method for synthesizing o-vanillin through utilizing 5-aldehyde vanillin | |
| WO2018189598A1 (en) | Integrated process for production of glycerol carbonate (4-hydroxymethyl-2-oxo-1, 3-dioxolane) and urea | |
| CN111875577B (en) | Preparation method of R-propylene carbonate | |
| CN102433363A (en) | Method for normal-temperature catalytic synthesis of 1,4-dihydropyridine compounds | |
| CN116535316A (en) | Method for recovering bisphenol A and carbonic ester by catalyzing alcoholysis of polycarbonate |
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 |