CN116554453A - Biodegradable poly (adipic acid)/butylene terephthalate-isosorbide copolyester and preparation method and application thereof - Google Patents
Biodegradable poly (adipic acid)/butylene terephthalate-isosorbide copolyester and preparation method and application thereof Download PDFInfo
- Publication number
- CN116554453A CN116554453A CN202310663079.5A CN202310663079A CN116554453A CN 116554453 A CN116554453 A CN 116554453A CN 202310663079 A CN202310663079 A CN 202310663079A CN 116554453 A CN116554453 A CN 116554453A
- Authority
- CN
- China
- Prior art keywords
- copolyester
- reaction
- isosorbide
- preparation
- heating
- 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
- 229920001634 Copolyester Polymers 0.000 title claims abstract description 103
- 229960002479 isosorbide Drugs 0.000 title claims abstract description 75
- 238000002360 preparation method Methods 0.000 title claims abstract description 46
- 229920005586 poly(adipic acid) Polymers 0.000 title abstract description 10
- 229920001707 polybutylene terephthalate Polymers 0.000 title abstract description 7
- KLDXJTOLSGUMSJ-JGWLITMVSA-N Isosorbide Chemical compound O[C@@H]1CO[C@@H]2[C@@H](O)CO[C@@H]21 KLDXJTOLSGUMSJ-JGWLITMVSA-N 0.000 claims abstract description 84
- 238000006243 chemical reaction Methods 0.000 claims abstract description 81
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 claims abstract description 49
- WOZVHXUHUFLZGK-UHFFFAOYSA-N dimethyl terephthalate Chemical compound COC(=O)C1=CC=C(C(=O)OC)C=C1 WOZVHXUHUFLZGK-UHFFFAOYSA-N 0.000 claims abstract description 41
- 238000010438 heat treatment Methods 0.000 claims abstract description 38
- 239000000178 monomer Substances 0.000 claims abstract description 28
- 239000001361 adipic acid Substances 0.000 claims abstract description 24
- 235000011037 adipic acid Nutrition 0.000 claims abstract description 24
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000003054 catalyst Substances 0.000 claims abstract description 21
- CDQSJQSWAWPGKG-UHFFFAOYSA-N butane-1,1-diol Chemical compound CCCC(O)O CDQSJQSWAWPGKG-UHFFFAOYSA-N 0.000 claims abstract description 14
- 238000000034 method Methods 0.000 claims abstract description 12
- 238000002844 melting Methods 0.000 claims abstract description 10
- 230000008018 melting Effects 0.000 claims abstract description 10
- 238000004806 packaging method and process Methods 0.000 claims abstract description 9
- 239000000203 mixture Substances 0.000 claims abstract description 7
- 230000008569 process Effects 0.000 claims abstract description 6
- 238000002156 mixing Methods 0.000 claims abstract description 4
- 229920003023 plastic Polymers 0.000 claims description 10
- 239000004033 plastic Substances 0.000 claims description 10
- 238000007789 sealing Methods 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 6
- REIDAMBAPLIATC-UHFFFAOYSA-N 4-methoxycarbonylbenzoic acid Chemical compound COC(=O)C1=CC=C(C(O)=O)C=C1 REIDAMBAPLIATC-UHFFFAOYSA-N 0.000 claims description 4
- 238000006068 polycondensation reaction Methods 0.000 abstract description 19
- 229920000728 polyester Polymers 0.000 abstract description 8
- 230000015572 biosynthetic process Effects 0.000 abstract description 4
- 238000003786 synthesis reaction Methods 0.000 abstract description 3
- 229920001896 polybutyrate Polymers 0.000 abstract 2
- WERYXYBDKMZEQL-UHFFFAOYSA-N butane-1,4-diol Chemical compound OCCCCO WERYXYBDKMZEQL-UHFFFAOYSA-N 0.000 description 46
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 42
- 238000005886 esterification reaction Methods 0.000 description 27
- 230000000052 comparative effect Effects 0.000 description 25
- 230000032050 esterification Effects 0.000 description 15
- 239000007788 liquid Substances 0.000 description 14
- 239000000047 product Substances 0.000 description 14
- 239000002994 raw material Substances 0.000 description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 14
- 239000006227 byproduct Substances 0.000 description 13
- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 description 8
- 238000009833 condensation Methods 0.000 description 8
- 230000005494 condensation Effects 0.000 description 8
- 238000002425 crystallisation Methods 0.000 description 7
- 230000008025 crystallization Effects 0.000 description 7
- 238000005485 electric heating Methods 0.000 description 7
- 239000012467 final product Substances 0.000 description 7
- 238000010926 purge Methods 0.000 description 7
- 238000003756 stirring Methods 0.000 description 7
- 150000002148 esters Chemical class 0.000 description 6
- 238000002309 gasification Methods 0.000 description 6
- 238000001938 differential scanning calorimetry curve Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 125000001570 methylene group Chemical group [H]C([H])([*:1])[*:2] 0.000 description 5
- 238000006116 polymerization reaction Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 4
- 229920000704 biodegradable plastic Polymers 0.000 description 4
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 4
- 229920001577 copolymer Polymers 0.000 description 4
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 230000000630 rising effect Effects 0.000 description 4
- 238000005481 NMR spectroscopy Methods 0.000 description 3
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N carbon dioxide Natural products O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 3
- 238000012512 characterization method Methods 0.000 description 3
- DNXDYHALMANNEJ-UHFFFAOYSA-N furan-2,3-dicarboxylic acid Chemical compound OC(=O)C=1C=COC=1C(O)=O DNXDYHALMANNEJ-UHFFFAOYSA-N 0.000 description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 3
- 238000002329 infrared spectrum Methods 0.000 description 3
- 230000009257 reactivity Effects 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- PUPZLCDOIYMWBV-UHFFFAOYSA-N (+/-)-1,3-Butanediol Chemical compound CC(O)CCO PUPZLCDOIYMWBV-UHFFFAOYSA-N 0.000 description 2
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- HEDRZPFGACZZDS-MICDWDOJSA-N Trichloro(2H)methane Chemical compound [2H]C(Cl)(Cl)Cl HEDRZPFGACZZDS-MICDWDOJSA-N 0.000 description 2
- ADCOVFLJGNWWNZ-UHFFFAOYSA-N antimony trioxide Chemical compound O=[Sb]O[Sb]=O ADCOVFLJGNWWNZ-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229920000747 poly(lactic acid) Polymers 0.000 description 2
- 229920001610 polycaprolactone Polymers 0.000 description 2
- 239000004626 polylactic acid Substances 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 230000010512 thermal transition Effects 0.000 description 2
- 229940083957 1,2-butanediol Drugs 0.000 description 1
- AXKZIDYFAMKWSA-UHFFFAOYSA-N 1,6-dioxacyclododecane-7,12-dione Chemical compound O=C1CCCCC(=O)OCCCCO1 AXKZIDYFAMKWSA-UHFFFAOYSA-N 0.000 description 1
- 238000005160 1H NMR spectroscopy Methods 0.000 description 1
- FBPFZTCFMRRESA-FSIIMWSLSA-N D-Glucitol Natural products OC[C@H](O)[C@H](O)[C@@H](O)[C@H](O)CO FBPFZTCFMRRESA-FSIIMWSLSA-N 0.000 description 1
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- SXSVTGQIXJXKJR-UHFFFAOYSA-N [Mg].[Ti] Chemical compound [Mg].[Ti] SXSVTGQIXJXKJR-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 230000001174 ascending effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 125000002619 bicyclic group Chemical group 0.000 description 1
- 229920000229 biodegradable polyester Polymers 0.000 description 1
- 239000004622 biodegradable polyester Substances 0.000 description 1
- BMRWNKZVCUKKSR-UHFFFAOYSA-N butane-1,2-diol Chemical compound CCC(O)CO BMRWNKZVCUKKSR-UHFFFAOYSA-N 0.000 description 1
- 235000019437 butane-1,3-diol Nutrition 0.000 description 1
- OWBTYPJTUOEWEK-UHFFFAOYSA-N butane-2,3-diol Chemical compound CC(O)C(C)O OWBTYPJTUOEWEK-UHFFFAOYSA-N 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 229920006238 degradable plastic Polymers 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- UVCJGUGAGLDPAA-UHFFFAOYSA-N ensulizole Chemical compound N1C2=CC(S(=O)(=O)O)=CC=C2N=C1C1=CC=CC=C1 UVCJGUGAGLDPAA-UHFFFAOYSA-N 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 125000004185 ester group Chemical group 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000005580 one pot reaction Methods 0.000 description 1
- 229920009537 polybutylene succinate adipate Polymers 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000000425 proton nuclear magnetic resonance spectrum Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000600 sorbitol Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- KKEYFWRCBNTPAC-UHFFFAOYSA-L terephthalate(2-) Chemical compound [O-]C(=O)C1=CC=C(C([O-])=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-L 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- CZDYPVPMEAXLPK-UHFFFAOYSA-N tetramethylsilane Chemical compound C[Si](C)(C)C CZDYPVPMEAXLPK-UHFFFAOYSA-N 0.000 description 1
- 238000002076 thermal analysis method Methods 0.000 description 1
- VXUYXOFXAQZZMF-UHFFFAOYSA-N titanium(IV) isopropoxide Chemical compound CC(C)O[Ti](OC(C)C)(OC(C)C)OC(C)C VXUYXOFXAQZZMF-UHFFFAOYSA-N 0.000 description 1
- 238000005809 transesterification reaction Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/66—Polyesters containing oxygen in the form of ether groups
- C08G63/668—Polyesters containing oxygen in the form of ether groups derived from polycarboxylic acids and polyhydroxy compounds
- C08G63/672—Dicarboxylic acids and dihydroxy compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G2230/00—Compositions for preparing biodegradable polymers
-
- 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
- Y02W90/00—Enabling technologies or technologies with a potential or indirect contribution to greenhouse gas [GHG] emissions mitigation
- Y02W90/10—Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics
Abstract
The invention belongs to the field of degradable polyesters, and particularly discloses biodegradable poly (adipic acid)/butylene terephthalate-isosorbide) copolyester and a preparation method and application thereof, wherein the method comprises the following steps: 1) Mixing terephthalic acid or dimethyl terephthalate, adipic acid, butanediol and isosorbide to obtain a monomer mixture; heating to monomer mixture melting under inert atmosphere, adding catalyst, continuously heating to 160-205 ℃ for reaction to obtain prepolymer; 2) Polycondensation reaction: continuously heating the prepolymer to 240 ℃, gradually reducing the pressure of a reaction system to 0.01-0.2kPa, then heating to 250 ℃ for reaction of 5-7h, and obtaining the catalyst after the reaction is finished. The PBIAT copolyester with higher toughness and strength is obtained by improving the synthesis process of the PBAT. Compared with pure PBAT copolyester, the tensile strength of the PBIAT copolyester can be improved to 27.1MPa, the elongation at break is improved to 784-2574%, the melting point is higher than 100 ℃, and the PBIAT copolyester has excellent processability and can be widely applied to the field of bio-based degradable film packaging.
Description
Technical Field
The invention belongs to the field of synthesis of degradable polyesters, and particularly relates to biodegradable poly (adipic acid)/butylene terephthalate-isosorbide copolyester, and a preparation method and application thereof.
Background
Plastic is a major material of current economy and society due to its versatility, durability, high strength to weight ratio, and excellent economy, and is used as disposable articles such as packaging. However, after a short first use, approximately nine pieces of plastic are not recycled but rather are landfilled, burned and even leaked into the natural environment, and the recycled plastic is also only used in low value products, in contrast to the recovery of plastic being much lower than the other two important materials, paper (58%) and steel (85%). Therefore, a wide consensus has been reached for disposable plastic packaging articles using novel biodegradable and compostable plastics, which are currently under intensive research, development and industrialization. Representative seven major classes of biodegradable plastics are respectively: polylactic acid PLA, poly (3-hydroxy alkyl acid ester) PHA, poly (epsilon-caprolactone) PCL, polyester-PBS/PBSA, aliphatic aromatic copolyester PBAT, polyvinyl alcohol (PVA) and carbon dioxide copolymer PPC.
The comprehensive performance of the poly (butylene adipate/terephthalate) (PBAT) is closest to that of general plastic polyethylene, and has become one of three biodegradable materials which are mainly developed worldwide. Although PBAT is the largest market share in replacing traditional disposable packaging and film materials, these biodegradable materials suffer from certain drawbacks compared to traditional plastics, such as higher production costs, lower strength, lower thermophysical properties, etc. In addition, PBAT is a fossil-based biodegradable plastic, which still leads to carbon dioxide emissions, so it is of great importance to study degradable plastics that obtain novel bio-based rigid monomers from renewable energy sources.
The bio-based rigid monomers on the market at present mainly comprise two types of furan dicarboxylic acid (FDCA) and Isosorbide (IS), the former IS one of 12 bio-based platform compounds which are identified by the United states department of energy and are preferentially developed and utilized, but the production technology of the FDCA IS not mature and has high price, the price of the bio-based rigid monomers IS hardly accepted when the bio-based rigid monomers are used as monomers for producing plastic packaging products for consumer markets, and the latter IS the only bio-based rigid monomer produced on a large scale and can be fully introduced into the consumer markets.
The isosorbide structure comprises two cis-fused Tetrahydrofuran (THF) rings, the included angle of the rings is 120 degrees, the whole molecule presents a V-shaped structure, one of two hydroxyl groups carried by the molecule extends out of the V-shaped annular structure (exo), the other hydroxyl group is positioned in the V-shaped annular structure (endo), and the difference of the reactivity of the two hydroxyl groups causes the polymer containing the isosorbide to have the problems of low molecular weight and the like. Patent CN113861399A discloses a biodegradable polyester PBIAT and a preparation method thereof, which are prepared by uniformly mixing adipic acid, terephthalic acid, isosorbide and butanediol, adding the mixture into a reaction kettle for esterification reaction, adding a catalyst, and increasing the temperature for polycondensation reaction to obtain the PBIAT copolyester. This patent has the following problems: (1) There are problems common in the art that prepolymer is largely withdrawn when a vacuum is drawn in the polycondensation stage; (2) Because of complex monomer components, the preparation process adopts a single temperature, which can cause insufficient reaction; (3) Lower temperatures are detrimental to the polymerization reaction due to the lower reactivity of isosorbide. All of the above problems result in products with low molecular weight and poor properties, and thus it is difficult to obtain PBIAT copolyesters with high molecular weight and excellent properties.
Disclosure of Invention
Aiming at the problems and the defects existing in the prior art, the invention aims to provide biodegradable poly (adipic acid)/butylene terephthalate-isosorbide (PBIAT) copolyester, and a preparation method and application thereof.
In order to achieve the aim of the invention, the technical scheme adopted by the invention is as follows:
the first aspect of the invention provides a method for preparing biodegradable PBIAT copolyester, comprising the following steps:
(1) Mixing terephthalic acid or methyl terephthalate with adipic acid, butanediol and isosorbide to obtain a monomer mixture; heating to monomer mixture melting under inert atmosphere, adding catalyst, continuously heating to 180-205 ℃ for reaction to obtain prepolymer;
(2) Continuously heating the prepolymer to 235-245 ℃, reducing the pressure of a reaction system to 0.01-0.2kPa, heating to 250-255 ℃ for reaction for 5-7 hours, and obtaining the biodegradable PBIAT copolyester after the reaction is finished.
In the step (1), four raw materials of terephthalic acid or methyl terephthalate, adipic acid, butanediol and isosorbide are stirred and mixed in an inert atmosphere, heated and melted, and then a catalyst is added for esterification or transesterification, for example, when 1, 4-butanediol is selected, an oligomer containing the following four structural units is prepared:
wherein IA represents a poly (adipic acid)/isosorbide polyester structural unit, BT represents a poly (adipic acid)/1, 4-butanediol polyester structural unit, IT represents a poly (terephthalic acid)/isosorbide polyester structural unit, and BA represents a poly (adipic acid)/1, 4-butanediol polyester structural unit.
According to the preparation method, preferably, the catalyst is added in the step (1), and the specific operation of continuously heating to 180-205 ℃ for reaction is as follows: adding an esterification catalyst, sealing a reaction system, heating to 160-170 ℃, and reacting for 1-2h at a temperature; then the condensation reflux is started, and the temperature is raised to 180-205 ℃ for reaction. The water and the methanol generated in the reaction process can exist in the reaction system in a gaseous state in the airtight system reaction for 1-2h, so that the system pressure is slightly higher than the normal pressure, the raw materials react in a micro-positive pressure state, and the reaction efficiency is improved.
According to the preparation method, preferably, in the step (1), the reaction is carried out by continuously heating to 180-205 ℃, and the specific operation is as follows: heating to 180-185 ℃ to react for 1-1.5h, and then heating to 200-205 ℃ to react for at least 1h. The invention adopts a gradient heating strategy to enable the reaction system to sequentially reach the optimal reaction temperature of adipic acid, isosorbide and dimethyl terephthalate, so that all raw materials can fully react, and the reaction efficiency is improved.
According to the production method, preferably, the lowering of the reaction system to 0.01 to 0.2kPa in the step (2) comprises: firstly, the pressure of the reaction system is reduced to 1.5 to 2.0kPa, the reaction system is maintained for 30 to 40 minutes, and the pressure value is continuously reduced to 0.01 to 0.2kPa.
According to the production method, preferably, the pressure of the reaction system is reduced to a speed of 1.5 to 2.0kPa at a rate of half every 15 minutes.
In the vacuum melt polycondensation stage, the system pressure is gradually and slowly reduced, particularly the pressure is maintained for 30-40min at 1.5-2.0kPa, and finally the melt polycondensation is carried out at the temperature of 250 ℃ under the high vacuum condition, so that the polycondensation reaction efficiency can be effectively improved, a large amount of prepolymer is prevented from being pumped out, and the molecular weight of the copolyester is improved.
According to the preparation method, preferably, the molar mass percentage of isosorbide in the step (1) is 5-40mol% and the molar mass percentage of butanediol is 60-95mol% based on 100mol% of the total molar mass of isosorbide and butanediol.
According to the invention, isosorbide is introduced into the PBAT, the rigid ring structure of the isosorbide is utilized to strengthen the molecular chain of the copolyester, so that the mechanical property of the copolyester PBAT can be obviously improved, and meanwhile, the unique V-shaped structure of the isosorbide is utilized to damage the crystallinity of the copolyester, so that the breaking elongation of the PBIAT is improved. However, when the molar mass percentage of isosorbide is too high, the polymerization reaction becomes more difficult, and the molecular weight and crystallinity of the copolyester are reduced at the same time, so that the mechanical properties are reduced. Thus, the molar mass percentage of isosorbide according to the invention is controlled to be 5 to 40mol%, preferably 5 to 20mol%.
According to the preparation method, preferably, the sum of the molar masses of butanediol and isosorbide is denoted as n 1 The sum of the molar masses of terephthalic acid or methyl terephthalate and adipic acid is denoted as n 2 ，n 1 :n 2 =1.1-1.3:1. If n 1 :n 2 Less than or equal to 1.1, especially when n 1 :n 2 When the polymerization rate is less than or equal to 0.9, the polymerization rate is greatly reduced, and copolyester with higher molecular weight is difficult to obtain, so the invention controls n 1 :n 2 =1.1-1.3:1, preferably n 1 :n 2 ＝1.1:1。
According to the preparation method, preferably, the catalyst is used in an amount of 0.02-0.06 wt% of the total mass of terephthalic acid or dimethyl terephthalate, adipic acid, butanediol and isosorbide.
According to the preparation method, preferably, the catalyst is at least one of tetrabutyl titanate, isopropyl titanate, antimony trioxide and a titanium magnesium bimetallic catalyst.
According to the preparation method, preferably, the butanediol is one or more of 1, 4-butanediol, 1, 3-butanediol, 1, 2-butanediol and 2, 3-butanediol.
In a second aspect, the present invention provides a biodegradable PBIAT copolyester product prepared by the method of the first aspect described above.
In a third aspect, the invention provides an application of the biodegradable PBIAT copolyester product in the field of plastic packaging.
Compared with the prior art, the invention has the following beneficial effects:
(1) The invention successfully introduces the bio-based rigid monomer isosorbide with a double-ring structure into the molecular chain of the PBAT by a one-pot synthesis method to prepare the bio-based degradable PBIAT copolyester, has simple process route, can be synthesized by using the existing copolyester production equipment, is easy for industrialized continuous production, and has higher economic benefit.
(2) In the esterification stage, the raw materials react for a certain time in a micro-positive pressure state, then gradually rise to different temperatures for a certain time, and the reaction system can sequentially reach the optimal reaction temperature of adipic acid, isosorbide and dimethyl terephthalate by adopting a temperature strategy of gradient rising, so that the raw materials can fully react, and the reaction efficiency is improved.
(3) In the polycondensation stage, the system pressure is gradually and slowly reduced, particularly the pressure is maintained for a certain time at 1.5-2.0kPa, and then the temperature is raised to perform high-vacuum melt polycondensation, so that the polycondensation reaction efficiency is effectively improved, a large amount of prepolymer is prevented from being extracted, and the molecular weight and the mechanical property of the PBIAT copolyester are improved.
(4) The PBIAT copolyester with higher toughness and strength is obtained by improving the synthesis process of the PBAT. Compared with pure PBAT copolyester, the PBIAT copolyester prepared by the invention has the highest tensile strength of 27.1MPa, the elongation at break of 784-2574 percent, the melting point of higher than 100 ℃, and excellent processability, and can be widely applied to the field of bio-based degradable film packaging.
(5) The bio-based rigid monomer isosorbide introduced into the molecular weight of the PBAT is derived from a chemical intermediate of starch and sorbitol, is a completely renewable bio-based monomer, can obviously improve the mechanical property of the PBAT, reduces the use of fossil resources, is beneficial to energy conservation and environmental protection, and has wide application prospect.
Drawings
FIG. 1 is a synthetic route diagram of a bio-based degradable poly (adipic acid)/poly (butylene terephthalate) -isosorbide copolyester of the present invention;
FIG. 2 is a copolyester obtained in example 1, example 4 and comparative example 1 1 H-NMR spectrum;
FIG. 3 is an infrared spectrum of the copolyester obtained in examples 1 to 5 and comparative example 1;
FIG. 4 is a graph of stress-strain curves for the copolyesters obtained in examples 1-5 and comparative examples 1-2;
FIG. 5 is a graph of ultimate tensile strength and elongation at break of the copolyesters obtained in examples 1-5 and comparative examples 1-2;
FIG. 6 shows DSC graphs of the copolyesters obtained in examples 1-4 and comparative example 1, (a) a secondary heating curve, and (b) a cooling curve;
FIG. 7 is a compression molded sheet of the copolyester obtained in example 5 and comparative example 1, wherein the left brown transparent sheet corresponds to example 5 and the right white sheet corresponds to example 1.
Detailed Description
The following examples are only suitable for further illustration of the invention. It should be noted that all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs unless otherwise indicated. The experimental methods in the following examples, in which specific conditions are not specified, are all conventional in the art or according to the conditions suggested by the manufacturer; the reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
In order to enable those skilled in the art to more clearly understand the technical scheme of the present invention, the technical scheme of the present invention will be described in detail with reference to specific embodiments.
The following examples and comparative examples provide a method of bio-based degradable poly (adipic acid)/poly (butylene terephthalate) -isosorbide (PBIAT) copolyesters having the chemical structure shown in formula I:
the starting materials in the following examples and comparative examples are all commercially available, and the monomer names and their corresponding abbreviations are shown in Table 1.
Table 1 names and abbreviations for monomers used in the examples
| Monomer name | Monomer abbreviations | Abbreviation for monomer residue |
| Terephthalic acid | PTA | T |
| Dimethyl terephthalate | DMT | T |
| Adipic acid | AA | A |
| 1, 4-butanediol | BDO | B |
| Isosorbide | IS | I |
In the following embodiments, the test analysis methods used are described below:
thermal analysis: the DSC curve of the sample is measured by DSC-60Plus of Shimadzu corporation, the thermal cycle program of primary heating-cooling-secondary heating is adopted, the test temperature range is-40-180 ℃, the temperature rising and falling rate is10 ℃/min, and the heat preservation time is 3min.
Mechanical properties: the 5B-type bars specified in ISO 572-2 were pressed with a vacuum laminator, and the tensile strength and elongation at break of the copolyesters PBAT and PBIAT were measured at a tensile rate of 100mm/min using a UTM-2502 electronic Universal tester manufactured by Sansi metering technology Co.
Chemical structure characterization: the chemical structure was measured using a Thermo Fisher Nicolet iS fourier transform infrared spectrometer and ATR mode. Further characterization was performed using a BrukerAVANCE III HD600MHz NMR spectrometer, wherein the solvent was tetramethylsilane with deuterated chloroform internal standard.
Example 1
Preparation of PB 95 I 5 AT copolyester, wherein B IS based on 100mol% of the total molar mass of BDO and IS 95 And I 5 Representing 95mol% BDO and 5mol% IS, respectively, the specific preparation method comprises the following steps, and the synthetic scheme can be seen in fig. 1:
(1) Preparation of PB by esterification 95 I 5 Prepolymer of AT copolyester
19.42g (0.1 mol) of dimethyl terephthalate, 14.61g (0.1 mol) of adipic acid, 18.81g (0.209 mol) of 1, 4-butanediol and 1.606g (0.011 mol) of isosorbide are weighed into a three-neck flask, then the three-neck flask is put into an electric heating furnace, a condensing device and a stirring device are built, and N is introduced 2 Continuously purging the reaction system and starting to heat, adding tetrabutyl titanate (0.01 g) serving as a catalyst accounting for 0.02% of the total mass of monomers when the raw materials completely become liquid, sealing the reaction system, closing a valve leading to a condensing device, heating to 160 ℃, enabling the system to perform esterification for 1.5h under the micro-positive pressure state generated by gasification of byproduct water and methanol, then opening the valve leading to the condensing device to continuously perform esterification, sequentially heating to 180 ℃ for reacting for 1.5h and 200 ℃ for at least 1h, ending the reaction until the volume of the collected byproducts (water and methanol) reaches about 85% of a theoretical value, and obtaining transparent liquid, namely PB 95 I 5 Prepolymer of AT copolyester.
(2) Preparation of PB by polycondensation 95 I 5 AT copolyester
The condensation collection container is replaced by a vacuumizing device, and the PB is obtained 95 I 5 Further rising of the prepolymer of the AT copolyesterGradually and slowly vacuumizing at 240 ℃ until the system pressure is reduced to about 1.5kPa for 30min, continuously vacuumizing until the pressure is maintained at 0.01-0.2kPa, then raising the reaction temperature to 250 ℃ for 5-7h, stopping vacuumizing when the product viscosity is high, and collecting the final product PB 95 I 5 An AT copolyester.
Example 2
Preparation of PB 90 I 10 AT copolyester, wherein B IS based on 100mol% of the total molar mass of BDO and IS 90 And I 10 Representing 90mol% BDO and 10mol% IS, respectively, the specific preparation method comprises the following steps, and the synthetic scheme can be seen in fig. 1:
(1) Preparation of PB by esterification 90 I 10 Prepolymer of AT copolyester
19.42g (0.1 mol) of dimethyl terephthalate, 14.61g (0.1 mol) of adipic acid, 17.82g (0.198 mol) of 1, 4-butanediol and 3.212g (0.022 mol) of isosorbide are weighed into a three-neck flask, then the three-neck flask is put into an electric heating furnace, a condensing device and a stirring device are built, and N is introduced 2 Continuously purging the reaction system and starting to heat, adding tetrabutyl titanate (0.01 g) serving as a catalyst accounting for 0.02% of the total mass of monomers when the raw materials completely become liquid, sealing the reaction system, closing a valve leading to a condensing device, heating to 170 ℃ to enable the system to perform esterification reaction for 2 hours under the micro-positive pressure state generated by gasification of byproduct water and methanol, then opening the valve leading to the condensing device to continue the esterification reaction, sequentially heating to 185 ℃ to perform reaction for 1.5 hours and at 205 ℃ to perform reaction for at least 1 hour, ending the reaction until the volume of the collected byproducts (water and methanol) reaches about 85% of theoretical value, and obtaining transparent liquid, namely PB 90 I 10 Prepolymer of AT copolyester.
(2) Preparation of PB by polycondensation 90 I 10 AT copolyester
The PB is obtained by replacing the condensation collection container with a vacuum device 90 I 10 The prepolymer of AT copolyester is further heated to 235 ℃ to start vacuumizing, and is reduced by half every 15min until the system pressure is reduced to about 1.5kPa, and is maintained for 30min, and vacuumizing is continued to maintain the pressureAfter the reaction temperature is maintained at 0.01-0.2kPa, the reaction temperature is raised to 250 ℃ for 5-7 hours, the vacuumizing is stopped when the viscosity of the product is high, and the final product PB is collected 90 I 10 An AT copolyester.
Example 3
Preparation of PB 85 I 15 AT copolyester, wherein B IS based on 100mol% of the total molar mass of BDO and IS 85 And I 15 Representing 85mol% BDO and 15mol% IS, respectively, the specific preparation method comprises the following steps, and the synthetic scheme can be seen in fig. 1:
(1) Preparation of PB by esterification 85 I 15 Prepolymer of AT copolyester
19.42g (0.1 mol) of dimethyl terephthalate, 14.61g (0.1 mol) of adipic acid, 16.83g (0.187 mol) of 1, 4-butanediol and 4.818g (0.033 mol) of isosorbide are weighed into a three-necked flask, then the three-necked flask is put into an electric heating furnace, a condensing device and a stirring device are built up, and N is introduced 2 Continuously purging the reaction system and starting to heat, adding tetrabutyl titanate (0.01 g) serving as a catalyst accounting for 0.02% of the total mass of monomers when the raw materials completely become liquid, sealing the reaction system, closing a valve leading to a condensing device, heating to 165 ℃ to enable the system to perform esterification reaction for 2 hours under the micro-positive pressure state generated by gasification of byproduct water and methanol, then opening the valve leading to the condensing device to continue the esterification reaction, sequentially heating to 185 ℃ to perform reaction for 1.5 hours at 200 ℃ for at least 1 hour, ending the reaction until the volume of the collected byproducts (water and methanol) reaches about 85% of theoretical value, and obtaining transparent liquid, namely PB 85 I 15 Prepolymer of AT copolyester.
(2) Preparation of PB by polycondensation 85 I 15 AT copolyester
The PB is obtained by replacing the condensation collection container with a vacuum device 85 I 15 The prepolymer of AT copolyester is further heated to 240 ℃ to start vacuumizing, and is reduced by half every 15min until the system pressure is reduced to about 1.5kPa, the reaction temperature is raised to 250 ℃ after the system pressure is maintained AT 0.01-0.2kPa, the reaction is carried out for 5-7h, the product viscosity is higher, the vacuumizing is stopped, and the final product PB is collected 85 I 15 AT copolymerizationAn ester.
Example 4
Preparation of PB 80 I 20 AT copolyester, wherein B IS based on 100mol% of the total molar mass of BDO and IS 80 And I 20 Representing 80mol% BDO and 20mol% IS, respectively, the specific preparation method comprises the following steps, and the synthetic scheme can be seen in fig. 1:
(1) Preparation of PB by esterification 80 I 20 Prepolymer of AT copolyester
19.42g (0.1 mol) of dimethyl terephthalate, 14.61g (0.1 mol) of adipic acid, 15.84g (0.176 mol) of 1, 4-butanediol and 6.424g (0.044 mol) of isosorbide are weighed into a three-neck flask, then the three-neck flask is put into an electric heating furnace, a condensing device and a stirring device are built up, and N is introduced 2 Continuously purging the reaction system and starting to heat, adding tetrabutyl titanate (0.01 g) serving as a catalyst accounting for 0.02% of the total mass of monomers when the raw materials completely become liquid, sealing the reaction system, closing a valve leading to a condensing device, heating to 165 ℃ to enable the system to perform esterification reaction for 1.5h under the micro-positive pressure state generated by gasification of byproduct water and methanol, then opening the valve leading to the condensing device to continue the esterification reaction, sequentially heating to 180 ℃ to react for 1.5h and 200 ℃ to react for at least 1h, ending the reaction until the volume of the collected byproducts (water and methanol) reaches about 85% of theoretical value, and obtaining transparent liquid, namely PB 80 I 20 Prepolymer of AT copolyester.
(2) Preparation of PB by polycondensation 80 I 20 AT copolyester
The PB is obtained by replacing the condensation collection container with a vacuum device 80 I 20 The prepolymer of AT copolyester is further heated to 245 ℃ to start vacuumizing, and is reduced by half every 15min until the system pressure is reduced to about 1.5kPa, the reaction temperature is raised to 255 ℃ after the system pressure is maintained AT 0.01-0.2kPa, the reaction is carried out for 5-7h, the product viscosity is higher, the vacuumizing is stopped, and the final product PB is collected 80 I 20 An AT copolyester.
Example 5
Preparation of PB 60 I 40 AT copolyesters, in which the total of BDO and ISB with a molar mass of 100mol% 60 And I 40 Respectively representing 60mol percent of BDO and 40mol percent of IS, the specific preparation method comprises the following steps:
(1) Preparation of PB by esterification 60 I 40 Prepolymer of AT copolyester
19.42g (0.1 mol) of dimethyl terephthalate, 14.61g (0.1 mol) of adipic acid, 11.88g (0.132 mol) of 1, 4-butanediol and 12.848g (0.088 mol) of isosorbide are weighed into a three-neck flask, then the three-neck flask is put into an electric heating furnace, a condensing device and a stirring device are built up, and N is introduced 2 Continuously purging the reaction system and starting to heat, adding tetrabutyl titanate (0.01 g) serving as a catalyst accounting for 0.02% of the total mass of monomers when the raw materials completely become liquid, sealing the reaction system, closing a valve leading to a condensing device, heating to 165 ℃ to enable the system to perform esterification reaction for 2 hours under the micro-positive pressure state generated by gasification of byproduct water and methanol, then opening the valve leading to the condensing device to continue the esterification reaction, sequentially heating to 185 ℃ to perform reaction for 1.5 hours and at 205 ℃ to perform reaction for at least 1 hour, ending the reaction until the volume of the collected byproducts (water and methanol) reaches about 85% of theoretical value, and obtaining transparent liquid, namely PB 60 I 40 Prepolymer of AT copolyester.
(2) Preparation of PB by polycondensation 60 I 40 AT copolyester
The PB is obtained by replacing the condensation collection container with a vacuum device 60 I 40 The prepolymer of AT copolyester is further heated to 245 ℃ to start vacuumizing, and is reduced by half every 15min until the system pressure is reduced to about 1.5kPa, the reaction temperature is raised to 255 ℃ after the system pressure is maintained AT 0.01-0.2kPa, the reaction is carried out for 5-7h, the product viscosity is higher, the vacuumizing is stopped, and the final product PB is collected 60 I 40 An AT copolyester.
Comparative example 1
The preparation method of the PBAT specifically comprises the following steps:
(1) Prepolymer for preparing PBAT copolyester by esterification reaction
19.42g (0.1 mol) of dimethyl terephthalate, 14.61g (0.1 mol) of adipic acid and 19.8g (0.22 mol) of 1, 4-butanediol are weighed inIn the three-mouth flask, then put the three-mouth flask into an electric heating furnace to build a condensing device and a stirring device, and introduce N 2 Continuously purging the reaction system and starting to heat, adding tetrabutyl titanate (0.01 g) serving as a catalyst accounting for 0.02% of the total mass of the monomers when the raw materials are completely changed into liquid, sealing the reaction system, closing a valve leading to a condensing device, heating to 175 ℃, enabling the system to perform esterification reaction for 2 hours under a micro-positive pressure state generated by gasification of byproduct water and methanol, then opening the valve leading to the condensing device to continuously perform esterification reaction, sequentially heating to 180 ℃ for reacting for 1.5 hours, and reacting for at least 1 hour at 200 ℃ until the volume of the collected byproducts (water and methanol) reaches about 85% of a theoretical value, and ending the reaction to obtain transparent liquid, namely the prepolymer of the PBAT copolyester.
(2) Polycondensation reaction for preparing PBAT copolyester
And (3) carrying out condensation collection and replacement to form a vacuum device, further heating the prepolymer of the obtained PBAT copolyester to 240 ℃, starting vacuumizing, reducing the prepolymer by half every 15min until the system pressure is reduced to about 1.5kPa, maintaining for 30min, continuously vacuumizing, maintaining the pressure at 0.01-0.2kPa, then raising the reaction temperature to 250 ℃, reacting for 5-7h, stopping vacuumizing when the product viscosity is high, and collecting the final product PBAT copolyester.
Comparative example 2
Preparation of PB 95 I 5 AT * The specific preparation method of the copolyester comprises the following steps:
(1) Preparation of PB by esterification 95 I 5 AT * Prepolymer of copolyester
19.42g (0.1 mol) of dimethyl terephthalate, 14.61g (0.1 mol) of adipic acid, 18.81g (0.209 mol) of 1, 4-butanediol and 1.606g (0.011 mol) of isosorbide are weighed into a three-neck flask, then the three-neck flask is put into an electric heating furnace, a condensing device and a stirring device are built, and N is introduced 2 Continuously purging the reaction system and starting to heat, adding tetrabutyl titanate (0.01 g) serving as a catalyst accounting for 0.02 percent of the total mass of the monomers when the raw materials completely become liquid, heating to 200 ℃ for reaction for 4-5 hours until the volume of the collected byproducts (water and methanol) reaches about 85 percent of the theoretical value, and ending the reaction to obtain transparent liquid, namely PB 95 I 50 AT * Prepolymer of copolyester.
(2) Preparation of PB by polycondensation 95 I 5 AT * Copolyester
The PB is obtained by replacing the condensation collection container with a vacuum device 95 I 5 AT * The prepolymer of the copolyester is further heated to 240 ℃ to start vacuumizing until the system pressure is reduced to 0.01-0.2kPa, then the reaction temperature is increased to 250 ℃ to react for 5-7 hours, vacuumizing is stopped when the viscosity of the product is high, and the final product PB is collected 95 I 5 AT * A copolyester.
For comparison purposes, the partial reaction conditions based on the amounts of the raw materials for preparing the copolyesters of examples 1-5 and comparative examples 1-2 are shown in Table 2, with 1, 4-butanediol accounting for 60mol% to 95mol% and isosorbide accounting for 5mol% to 40mol% based on 100mol% of the total molar mass of 1, 4-butanediol and isosorbide. The dimethyl terephthalate accounts for 50mol% and the adipic acid accounts for 50mol% based on 100mol% of the total molar mass of the dimethyl terephthalate and the adipic acid. The following is shown:
TABLE 2 raw material amounts and reaction procedure
| Project | Example 1 | Example 2 | Example 3 | Example 4 | Example 5 | Comparative example 1 | Comparative example 2 |
| Product name | PB 95 I 5 AT | PB 90 I 10 AT | PB 85 I 15 AT | PB 80 I 20 AT | PB 60 I 40 AT | PBAT | PB 95 I 5 AT* |
| 1, 4-butanediol (mol%) | 95 | 90 | 85 | 80 | 60 | 100 | 95 |
| Isosorbide (mol%) | 5 | 10 | 15 | 20 | 40 | 0 | 5 |
| Dimethyl terephthalate (mol%) | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
| Adipic acid (mol%) | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
| Esterification stage/micro positive pressure state | Has the following components | Has the following components | Has the following components | Has the following components | Has the following components | Has the following components | Without any means for |
| Polycondensation stage/staged depressurization | Has the following components | Has the following components | Has the following components | Has the following components | Has the following components | Has the following components | Without any means for |
Structural characterization and performance testing
1. Nuclear magnetic resonance hydrogen spectrum
FIG. 2 shows the PBIAT copolyesters and pairs obtained in example 1 and example 4The nuclear magnetic resonance hydrogen spectrum of the PBAT copolyester obtained in the proportion 1 is shown in FIG. 2 1 When the H-NMR spectrum is analyzed, the sharp strong peak d at delta 8.09ppm is attributed to a proton on the benzene ring, and two similar groups of peaks at delta 4.43, 4.37, 4.14 and 4.09ppm are respectively attributed to methylene e and e' on the adjacent ester carbonyl group on the 1, 4-butanediol connected with aliphatic group or aromatic group, wherein the proton chemical shift on the methylene on the adjacent ester carbonyl group on the 1, 4-butanediol is shifted to the low field due to the formation of a larger conjugated structure of the ester carbonyl group connected with the benzene ring; the sharp peak at δ2.32ppm is attributed to proton g on the methylene group of the adipic acid segment adjacent to the ester carbonyl group; the peak at δ1.97ppm is attributed to proton f on the methylene group of the 1, 4-butanediol unit other than the adjacent ester carbonyl group; the peak at δ1.65ppm is assigned to proton h on the methylene group of the adipic acid unit other than the adjacent ester carbonyl group; the characteristic peak of the isosorbide unit is very tiny and concentrated between delta 5.5 and 3.5ppm, and the characteristic peak is obviously increased along with the rising of the addition amount of the isosorbide, which proves that the isosorbide chain segment successfully enters the copolyester.
2. Infrared spectrum
FIG. 3 is an infrared spectrum of the PBIAT copolyester obtained in examples 1 to 5 and the PBAT copolyester obtained in comparative example. 1713cm in FIG. 3 -1 The strong and sharp absorption peak is derived from C=O, 1238cm -1 The strong absorption peak at the position is derived from asymmetric vibration of ArC-O-C bond in polyester ester group, 1016cm -1 Is provided with a plurality of stretching vibration produced by methylene-connected C-C bonds, 874cm -1 The weak peak at which represents benzene ring, 723cm -1 The strong and sharp absorption peak is caused by out-of-plane vibration of C-H on the benzene ring. Examples 1-5 were at 972cm compared to comparative example 1 -1 There is a very weak absorption peak, which is a characteristic peak of isosorbide units in the polyester segment, derived from symmetrical vibration of the C-O-C groups in the isosorbide fused bicyclic ring, indicating that the examples of the invention successfully produced PBIAT.
3. Mechanical properties
The mechanical properties of the copolyester samples prepared in examples 1-5 and comparative examples 1-2 were tested, FIG. 4 shows stress strain curves of the copolyesters obtained in examples 1-5 and comparative examples 1-2, and FIG. 5 shows ultimate tensile strength and elongation at break of the copolyesters obtained in examples 1-5 and comparative examples 1-2, specific data of which are shown in Table 3, wherein the measurement standards of tensile strength and elongation at break were developed according to national standard GB/T1040.3-2006.
Table 3 mechanical property data for examples 1-4 and comparative examples 1-2:
| numbering device | Sample name | Tensile Strength (MPa) | Elongation at break (%) |
| Example 1 | PB 95 I 5 AT | 27.1 | 1271.8 |
| Example 2 | PB 90 I 10 AT | 17.6 | 1035.2 |
| Example 3 | PB 85 I 15 AT | 14.2 | 1024.1 |
| Example 4 | PB 80 I 20 AT | 9.1 | 784.3 |
| Example 5 | PB 60 I 40 AT | 1.6 | 2574.5 |
| Comparative example 1 | PBAT | 12.2 | 778.3 |
| Comparative example 2 | PB 95 I 5 AT* | 14.9 | 800.7 |
As can be seen from fig. 4, 5 and table 3, the addition of isosorbide (example 1) significantly enhances the mechanical properties of the copolyester PBIAT compared to PBAT without isosorbide (comparative example 1), because the introduction of the rigid ring in the isosorbide structure has a certain reinforcing effect on the polymer molecular chain, while the unique V-shaped structure of isosorbide destroys the crystallinity of the copolymer, thereby resulting in an improvement of the tensile strength and elongation at break of the PBIAT. However, as the amount of isosorbide increases (examples 2 to 4), the mechanical properties tend to decrease again, since the low reactivity of the-OH in isosorbide makes the polymerization difficult, which leads to a decrease in the molecular weight of the polymer and thus to an influence on the mechanical properties. When the isosorbide unit content in the molecular chain further increases (example 5), the copolymer exhibits an amorphous state, at which time the copolymer strength is low and has extremely high elongation at break.
Compared with comparative example 2, in which the preparation process was not optimized (i.e., the micro-positive pressure state was not maintained and the temperature was not raised in sections during the esterification stage, and the pressure was not lowered in sections during the polycondensation stage), the mechanical properties of the samples of examples 1 to 4 were greatly improved. The esterification stage can maintain a micro positive pressure state for a period of time, so that the reaction efficiency can be improved, and meanwhile, the reaction system can sequentially reach the optimal reaction temperature of adipic acid, isosorbide and dimethyl terephthalate by adopting a gradient heating strategy in the esterification stage, so that the reaction efficiency is maximized. In addition, the invention adopts sectional depressurization in the vacuum melting polycondensation stage, especially keeps for a long time at about 1.5kpa, and finally polycondensates under the vacuum condition of 250 ℃, so that a large amount of prepolymer can be effectively prevented from being pumped out, the molecular weight of the copolyester is obviously improved, and the mechanical property of a sample is further influenced.
DSC curve
FIG. 6 shows DSC curves of the PBIAT copolyesters obtained in examples 1-4 and the PBAT copolyester obtained in comparative example 1, wherein (a) is a DSC curve of the second temperature rise and (b) is a DSC curve of the temperature decrease. The thermal transition performance data in the graph are listed in Table 4, T c Represents the crystallization temperature, deltaH c Indicating the crystallization enthalpy value, T g Indicating the glass transition temperature, T cc Represents the cold crystallization temperature, deltaH cc Indicating the enthalpy value, T, of cold crystallization m Represents melting point, deltaH m Indicating the melting enthalpy value.
TABLE 4 thermal transition Properties
As can be seen from FIGS. 6 and 4, as the content of isosorbide having a rigid structure in the polymer segment increases, the segment movement becomes more difficult, and is reflected in T g The upper part shows an ascending trend. The difficulty of segment movement and the V-shaped structure of isosorbide jointly destroy the regularity of molecular weight, so that the crystallinity of the PBIAT copolyester is obviously reduced along with the increase of isosorbide units, and the melting point, the crystallization temperature and the crystallization enthalpy of the copolyester are simultaneously reduced. Further, when the isosorbide content is more than 15mol% (examples 3 and 4), a distinct cold crystallization peak appears. Thus (2)As the isosorbide content continues to increase (example 5), we can predict that the copolyester will exhibit transparency due to reduced crystallinity.
5. Transparency of
A graph of a compression molded sheet of the PBIAT copolyester obtained in example 5 and the copolyester obtained in comparative example 1 is shown in FIG. 7, which shows that the PBIAT copolyester has a certain transparency, consistent with the predicted results of the present invention.
In summary, the PBIAT copolyester with higher toughness and strength is obtained by optimizing the preparation process of the PBIAT copolyester. Compared with pure PBAT copolyester, the PBIAT copolyester prepared by the invention has the highest tensile strength of 27.1MPa, the elongation at break of 784-2574 percent, the melting point of higher than 100 ℃, and excellent processability, and can be widely applied to the field of bio-based degradable film packaging.
The embodiments described above are specific embodiments of the present invention, but the embodiments of the present invention are not limited to the embodiments described above, and any other combinations, changes, modifications, substitutions, and simplifications that do not exceed the design concept of the present invention fall within the scope of the present invention.
Claims (10)
1. The preparation method of the biodegradable PBIAT copolyester is characterized by comprising the following steps of:
(1) Mixing terephthalic acid or dimethyl terephthalate with adipic acid, butanediol and isosorbide to obtain a monomer mixture; heating to monomer mixture melting under inert atmosphere, adding catalyst, continuously heating to 180-205 ℃ for reaction to obtain prepolymer;
(2) Continuously heating the prepolymer to 235-245 ℃, reducing the pressure of a reaction system to 0.01-0.2kPa, then heating to 250-255 ℃ to react for 5-7h, and obtaining the biodegradable PBIAT copolyester after the reaction is finished.
2. The preparation method according to claim 1, wherein the catalyst is added in the step (1), and the specific operation of continuously heating to 180-205 ℃ for reaction is as follows: adding a catalyst, sealing a reaction system, heating to 160-170 ℃, and reacting at a temperature of 1-2h; then the condensing and collecting device is started, and the temperature is continuously increased to 180-205 ℃ for reaction.
3. The preparation method according to claim 1, wherein the step (1) is performed by continuously heating to 180-205 ℃, and the specific operations are as follows: the temperature is raised to 180-185 ℃ to react 1-1.5. 1.5h, and then the temperature is raised to 200-205 ℃ to react at least 1h.
4. A production method according to claim 1 or 2 or 3, wherein the lowering of the pressure of the reaction system in the step (2) to 0.01 to 0.2kPa comprises: firstly, the pressure of the reaction system is reduced to 1.5 to 2.0kPa, the reaction system is maintained for 30 to 40 minutes, and the pressure is continuously reduced to 0.01 to 0.2kPa.
5. The process according to claim 4, wherein the pressure of the reaction system is reduced to a speed of 1.5 to 2.0kPa at which the pressure of the system is reduced by half every 15 minutes.
6. The process according to claim 5, wherein the molar mass percentage of isosorbide in the step (1) is 5 to 40mol% and the molar mass percentage of butanediol is 60 to 95mol% based on 100mol% of the total molar mass of isosorbide and butanediol.
7. The process according to claim 6, wherein the sum of the molar masses of butanediol and isosorbide is n 1 The sum of the molar masses of adipic acid and terephthalic acid or dimethyl terephthalate is denoted as n 2 ，n 1 : n 2 = 1.1-1.3 : 1。
8. The preparation method according to claim 5 or 6, wherein the catalyst is used in an amount of 0.02-wt% to 0.06-wt% of the total mass of terephthalic acid or methyl terephthalate, adipic acid, butanediol, and isosorbide.
9. Biodegradable PBIAT copolyester product prepared by the preparation method according to any one of claims 1 to 8.
10. Use of the biodegradable PBIAT copolyester product according to claim 9 in the field of plastic packaging.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310663079.5A CN116554453A (en) | 2023-06-06 | 2023-06-06 | Biodegradable poly (adipic acid)/butylene terephthalate-isosorbide copolyester and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310663079.5A CN116554453A (en) | 2023-06-06 | 2023-06-06 | Biodegradable poly (adipic acid)/butylene terephthalate-isosorbide copolyester and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116554453A true CN116554453A (en) | 2023-08-08 |
Family
ID=87491637
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310663079.5A Pending CN116554453A (en) | 2023-06-06 | 2023-06-06 | Biodegradable poly (adipic acid)/butylene terephthalate-isosorbide copolyester and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116554453A (en) |
-
2023
- 2023-06-06 CN CN202310663079.5A patent/CN116554453A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Xu et al. | Poly (butylene succinate) and its copolymers: Research, development and industrialization | |
| CN1861660B (en) | Biologic degradable copolyester and preparation process thereof | |
| CN111269405B (en) | Preparation method of bio-based polyester for inhibiting discoloration | |
| CN108659209A (en) | A kind of 2,5- furandicarboxylic acids copolyesters and its preparation method and application | |
| CN113929882B (en) | Biodegradable random copolymer based on polyglycolic acid and preparation method thereof | |
| CN110407991A (en) | A kind of segmented copolymer and preparation method thereof based on 2,5- furandicarboxylic acid polyester and fatty poly-ester carbonate | |
| AU2013342037B2 (en) | Poly(dihydroferulic acid) a biorenewable polyethylene terephthalate mimic derived from lignin and acetic acid and copolymers thereof | |
| CN108473666A (en) | Pet polymer with the resistive connection crystalline substance comonomer that can be biological source | |
| Bi et al. | Synthesis, thermal and mechanical properties of fully biobased poly (butylene-co-propylene 2, 5-furandicarboxylate) copolyesters with low contents of propylene 2, 5-furandicarboxylate units | |
| CN106633014A (en) | A synthetic method of resin used for a degradable membrane material having a high molecular-weight and high barrier performance | |
| CN107245140B (en) | Aliphatic-aromatic copolyester of high molecular weight and its preparation method and application | |
| Min et al. | From fossil resources to renewable resources: Synthesis, structure, properties and comparison of terephthalic acid-2, 5-furandicarboxylic acid-diol copolyesters | |
| CN114106300A (en) | Copolyester and preparation method thereof | |
| CN115028819B (en) | Method for preparing clothes-kang acid-based dipyrrolidone dicarboxylic acid and related polyester thereof | |
| CN116554453A (en) | Biodegradable poly (adipic acid)/butylene terephthalate-isosorbide copolyester and preparation method and application thereof | |
| CN114292388B (en) | Preparation method of degradable PET-based copolyester | |
| JP2004323627A (en) | Method for polyester production | |
| TWI703171B (en) | Bibenzoate copolyesters and methods to produce them | |
| CN115109045A (en) | Preparation method of bio-based heterocyclic monomer and homopolyester thereof | |
| CN115403749A (en) | Degradable poly (butylene adipate/terephthalate-co-glycollic acid) copolyester and preparation method thereof | |
| US3310532A (en) | Method for preparation of modified polyesters having fiber- and film-forming properties | |
| CN113512187A (en) | Transparent and degradable PBAT material, preparation method and application thereof | |
| CN114057998A (en) | 2, 5-furandicarboxylic acid copolyester and preparation method thereof | |
| CN115785406B (en) | Preparation method of kilogram-level polyethylene glycol oxalate | |
| TW201833174A (en) | Bibenzoate copolyesters |
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 |