CN116789946A - High-temperature-resistant polylactic acid block elastomer and preparation method thereof - Google Patents
High-temperature-resistant polylactic acid block elastomer and preparation method thereof Download PDFInfo
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- 229920000747 poly(lactic acid) Polymers 0.000 title claims abstract description 62
- 239000004626 polylactic acid Substances 0.000 title claims abstract description 62
- 229920001971 elastomer Polymers 0.000 title claims abstract description 26
- 239000000806 elastomer Substances 0.000 title claims abstract description 26
- 238000002360 preparation method Methods 0.000 title abstract description 13
- 229920001432 poly(L-lactide) Polymers 0.000 claims abstract description 55
- 229920001434 poly(D-lactide) Polymers 0.000 claims abstract description 48
- 229920001400 block copolymer Polymers 0.000 claims abstract description 19
- RBMHUYBJIYNRLY-UHFFFAOYSA-N 2-[(1-carboxy-1-hydroxyethyl)-hydroxyphosphoryl]-2-hydroxypropanoic acid Chemical compound OC(=O)C(O)(C)P(O)(=O)C(C)(O)C(O)=O RBMHUYBJIYNRLY-UHFFFAOYSA-N 0.000 claims abstract description 18
- JVTAAEKCZFNVCJ-REOHCLBHSA-N L-lactic acid Chemical compound C[C@H](O)C(O)=O JVTAAEKCZFNVCJ-REOHCLBHSA-N 0.000 claims abstract description 17
- 238000002156 mixing Methods 0.000 claims abstract description 14
- USIUVYZYUHIAEV-UHFFFAOYSA-N diphenyl ether Chemical compound C=1C=CC=CC=1OC1=CC=CC=C1 USIUVYZYUHIAEV-UHFFFAOYSA-N 0.000 claims description 28
- KDYFGRWQOYBRFD-UHFFFAOYSA-N succinic acid Chemical compound OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 claims description 28
- 239000000178 monomer Substances 0.000 claims description 23
- 229920000728 polyester Polymers 0.000 claims description 21
- 239000003054 catalyst Substances 0.000 claims description 17
- WERYXYBDKMZEQL-UHFFFAOYSA-N butane-1,4-diol Chemical compound OCCCCO WERYXYBDKMZEQL-UHFFFAOYSA-N 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 16
- OFOBLEOULBTSOW-UHFFFAOYSA-N Malonic acid Chemical compound OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 claims description 14
- 239000000126 substance Substances 0.000 claims description 13
- JJTUDXZGHPGLLC-IMJSIDKUSA-N 4511-42-6 Chemical compound C[C@@H]1OC(=O)[C@H](C)OC1=O JJTUDXZGHPGLLC-IMJSIDKUSA-N 0.000 claims description 12
- JJTUDXZGHPGLLC-UHFFFAOYSA-N lactide Chemical compound CC1OC(=O)C(C)OC1=O JJTUDXZGHPGLLC-UHFFFAOYSA-N 0.000 claims description 12
- 239000001384 succinic acid Substances 0.000 claims description 12
- 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 claims description 11
- KSBAEPSJVUENNK-UHFFFAOYSA-L tin(ii) 2-ethylhexanoate Chemical compound [Sn+2].CCCCC(CC)C([O-])=O.CCCCC(CC)C([O-])=O KSBAEPSJVUENNK-UHFFFAOYSA-L 0.000 claims description 11
- 239000002253 acid Substances 0.000 claims description 8
- 229920000180 alkyd Polymers 0.000 claims description 7
- 239000002994 raw material Substances 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 5
- OOPRGQQMVMBKMD-UHFFFAOYSA-N 4-formyloxybutyl formate Chemical compound O=COCCCCOC=O OOPRGQQMVMBKMD-UHFFFAOYSA-N 0.000 claims description 4
- 239000003999 initiator Substances 0.000 claims description 3
- 238000007151 ring opening polymerisation reaction Methods 0.000 claims description 3
- 229920000428 triblock copolymer Polymers 0.000 claims description 3
- 239000013078 crystal Substances 0.000 abstract description 18
- 239000002131 composite material Substances 0.000 abstract description 10
- 230000015572 biosynthetic process Effects 0.000 abstract description 9
- 238000003786 synthesis reaction Methods 0.000 abstract description 7
- 238000002844 melting Methods 0.000 abstract description 6
- 230000008018 melting Effects 0.000 abstract description 6
- 239000002861 polymer material Substances 0.000 abstract description 6
- -1 diformyl butanediol Chemical compound 0.000 abstract description 3
- 238000002425 crystallisation Methods 0.000 abstract description 2
- 230000008025 crystallization Effects 0.000 abstract description 2
- 230000007613 environmental effect Effects 0.000 abstract 1
- 238000009776 industrial production Methods 0.000 abstract 1
- 238000006116 polymerization reaction Methods 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 40
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 39
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 36
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 24
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 24
- 229920000642 polymer Polymers 0.000 description 14
- 238000010438 heat treatment Methods 0.000 description 13
- 239000000203 mixture Substances 0.000 description 13
- 238000005886 esterification reaction Methods 0.000 description 12
- 229910052757 nitrogen Inorganic materials 0.000 description 12
- 230000001376 precipitating effect Effects 0.000 description 12
- 238000003756 stirring Methods 0.000 description 12
- 229960005137 succinic acid Drugs 0.000 description 11
- 238000001816 cooling Methods 0.000 description 7
- 229920001577 copolymer Polymers 0.000 description 7
- 238000011084 recovery Methods 0.000 description 7
- 241000209140 Triticum Species 0.000 description 6
- 235000021307 Triticum Nutrition 0.000 description 6
- 239000012190 activator Substances 0.000 description 6
- 238000001035 drying Methods 0.000 description 6
- 230000032050 esterification Effects 0.000 description 6
- 238000001914 filtration Methods 0.000 description 6
- 238000006068 polycondensation reaction Methods 0.000 description 6
- 238000005086 pumping Methods 0.000 description 6
- 238000007789 sealing Methods 0.000 description 6
- 238000001291 vacuum drying Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 229920001634 Copolyester Polymers 0.000 description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 238000005481 NMR spectroscopy Methods 0.000 description 3
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 3
- 238000000113 differential scanning calorimetry Methods 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 239000004721 Polyphenylene oxide Substances 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-MICDWDOJSA-N Trichloro(2H)methane Chemical compound [2H]C(Cl)(Cl)Cl HEDRZPFGACZZDS-MICDWDOJSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000001938 differential scanning calorimetry curve Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005227 gel permeation chromatography Methods 0.000 description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 2
- 229920000570 polyether Polymers 0.000 description 2
- 230000002194 synthesizing effect Effects 0.000 description 2
- 229920006346 thermoplastic polyester elastomer Polymers 0.000 description 2
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229920003232 aliphatic polyester Polymers 0.000 description 1
- 229920006125 amorphous polymer Polymers 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- CDQSJQSWAWPGKG-UHFFFAOYSA-N butane-1,1-diol Chemical group CCCC(O)O CDQSJQSWAWPGKG-UHFFFAOYSA-N 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
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- 230000001276 controlling effect Effects 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- VILAVOFMIJHSJA-UHFFFAOYSA-N dicarbon monoxide Chemical compound [C]=C=O VILAVOFMIJHSJA-UHFFFAOYSA-N 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 125000001434 methanylylidene group Chemical group [H]C#[*] 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 125000001570 methylene group Chemical group [H]C([H])([*:1])[*:2] 0.000 description 1
- SNVLJLYUUXKWOJ-UHFFFAOYSA-N methylidenecarbene Chemical compound C=[C] SNVLJLYUUXKWOJ-UHFFFAOYSA-N 0.000 description 1
- 229920006030 multiblock copolymer Polymers 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 229920001748 polybutylene Polymers 0.000 description 1
- 229920001610 polycaprolactone Polymers 0.000 description 1
- 239000004632 polycaprolactone Substances 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920001451 polypropylene glycol Polymers 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
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- 239000002904 solvent Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 229920002725 thermoplastic elastomer Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Landscapes
- Polyesters Or Polycarbonates (AREA)
Abstract
The invention relates to a high-temperature-resistant polylactic acid block elastomer and a preparation method thereof, and relates to the technical field of high polymer material synthesis. The product consists of two components, namely, the L-polylactic acid-b-poly (butylene succinate-co-diphenyl ether diformyl butanediol) ester-b-L-polylactic acid and the D-polylactic acid-b-poly (butylene succinate-co-diphenyl ether diformyl butanediol) -b-D-polylactic acid. The two components are fused and blended to form the composite elastomer with PLLA/PDLA Stereocomplex Crystals (SC) as hard segments and PBSO as soft segments, wherein the hard segments have the characteristics of crystallization, high melting point, high strength and high modulus. The invention has simple operation, can carry out polymerization and blending by a common device, and is easy for industrial production. The block copolymer obtained by the invention has excellent high temperature resistance, high rebound and biodegradability, accords with the development trend of a high polymer material with resource conservation and environmental friendliness, and has wide application prospect.
Description
Technical Field
The invention belongs to the technical field of high polymer materials, and particularly relates to a high-temperature-resistant polylactic acid block elastomer and a preparation method thereof.
Technical Field
Thermoplastic polyester elastomer (TPEE) is an ase:Sub>A-B-ase:Sub>A type triblock or (AB) n type multiblock copolymer copolymerized from high melting point, high hardness crystalline short chain polyester (such as PBT, etc.) hard segments and amorphous long chain polyether (such as polyethylene glycol ether, polypropylene glycol ether, polybutylene glycol ether, etc.) or polyester (such as aliphatic polyester like polycaprolactone, etc.) soft segments. The crystallized polyester hard chain segments are aggregated into crystallized micro-areas, dispersed in a continuous phase formed by soft segment polyether or soft segment polyester, the crystallized phase plays a physical crosslinking role, and the crystallized micro-areas are destroyed when heated and are in melt fluidity, and the crystallized micro-areas are formed after cooling, so that the reversibility is realized. The hard segments of the crystalline phase impart strength and plasticity to the polymer and the soft segments of the amorphous phase impart elasticity to the polymer. The block copolymer has polymer chain segments with different properties on the structure, so that microphase separation is formed, and the block copolymer has very unique performance. There is a great deal of interest in many areas of application, particularly as thermoplastic elastomers, adhesives and surfactants.
Disclosure of Invention
The invention aims to form a unique Stereocomplex Crystal (SC) with PLLA and PDLA, wherein the crystal has a higher melting point (T m =210 ℃), thereby imparting a characteristic of high heat resistance. Based on the above, the invention prepares PLLA and PDLA blocks respectively from the aspect of molecular structure designThe polymer is prepared by synthesizing block polymers with different hard and soft block chain segment lengths and regulating and controlling the mass ratio of two block polymer components, and adopts a melt blending mode to obtain the polymer elastomer with high heat resistance and controllable rebound performance. The invention provides a heat-resistant polymer elastomer with good rebound resilience, which can resist 160 ℃.
The technical scheme for achieving the aim of the invention is as follows:
the high temperature resistant polylactic acid block elastomer is characterized by comprising two components of:
the chemical structural formula of the L-polylactic acid-b-poly (butylene succinate-co-diphenyl ether butylene diformate) ester-b-L-polylactic acid triblock copolymer, namely PLLA-b-PBSO-b-PLLA, is as follows:
the chemical structural formula of the tri-block copolymer of the dextrorotatory polylactic acid-b-poly (butylene succinate-co-diphenyl ether butylene diformate) ester-b-dextrorotatory polylactic acid, namely PDLA-b-PBSO-b-PDLA, is as follows:
the preparation method of the high-temperature-resistant polylactic acid block elastomer comprises the following steps:
(1) Preparing hydroxyl-terminated polyester HO-PBSO-OH by taking 1, 4-butanediol, succinic acid and diphenyl ether dicarboxylic acid as raw materials and tetrabutyl titanate as a catalyst; then using HO-PBSO-OH as a macromolecular initiator, using L-lactide LLA or D-lactide DLA as a monomer, using stannous octoate as a catalyst, and preparing PLLA-b-PBSO-b-PLLA and PDLA-b-PBSO-b-PDLA by ring opening polymerization;
(2) PLLA-b-PBSO-b-PLLA and PDLA-b-PBSO-b-PDLA are subjected to melt blending to prepare the PLLA-b-PBSO-b-PLLA/PDLA-b-PBSO-b-PDLA high temperature resistant polylactic acid block elastomer.
The preparation method comprises the following steps: the molar ratio of the alkyd in the step (1) is 4:1, and the molar ratio of the succinic acid to the diphenyl ether dicarboxylic acid is 1:1.
The preparation method comprises the following steps: the molecular weight of the PBSO block in the PLLA-b-PBSO-b-PLLA and the PDLA-b-PBSO-b-PDLA in the step (1) is 20000-50000g/mol, and the molecular weight of the single PLLA block and the single PDLA block in the PLLA-b-PBSO-b-PLLA and the single PDLA block in the PDLA-b-PBSO-b-PDLA is 4000-10000g/mol.
The preparation method comprises the following steps: in the step (2), the PLLA-b-PBSO-b-PLLA accounts for 40% -60% and the PLLA-b-PBSO-b-PLLA accounts for 60% -40%.
The preparation method comprises the following steps: in the step (2), the materials are melted and blended in an internal mixer, the internal mixing temperature is 180 ℃, and the internal mixing time is 5min.
The preparation method comprises the following steps: the amount of tetrabutyl titanate used in step (1) was 0.5% of the molar amount of the acid monomer.
The preparation method comprises the following steps: the amount of tetrabutyl titanate used in step (1) was 0.5% of the molar amount of the acid monomer.
The preparation method comprises the following steps: the amount of stannous octoate is 0.5% of the mass of the levorotatory lactide LLA or the dextrorotatory lactide DLA lactide.
In some specific technical schemes, the preparation method of the high-temperature-resistant polylactic acid block elastomer comprises the following steps:
(1) Adding 1, 4-butanediol, succinic acid and diphenyl ether dicarboxylic acid into a reactor with a stirring device, a condensing device and a nitrogen protection device; adding tetrabutyl titanate catalyst into a reactor, opening condensed water, and introducing N 2 Heating to 180 ℃, and after the monomer is completely melted, stirring at constant temperature for esterification for 3-4 hours to complete the esterification reaction stage; and then removing the condensing device, replacing the condensing device with a vacuumizing device provided with a safety bottle, a wheat type vacuum gauge and an oil pump, carrying out a polycondensation stage, heating to 220 ℃, continuously reacting for 3-4 hours, collecting a product at room temperature under the vacuum degree of 50-80Pa, dissolving the product with chloroform, precipitating with methanol, filtering and drying to obtain the purified hydroxyl-terminated polyester HO-PBSO-OH.
Adding hydroxyl-terminated polyester HO-PBSO-OH, toluene and stannous octoate catalyst into a reactor, and adding the hydroxyl-terminated polyester HO-PBSO-OH, toluene and stannous octoate catalyst into the reactor, wherein N is 2 Under protection ofReacting for 4 hours at 80 ℃, closing nitrogen, vacuumizing, and removing toluene to obtain a prepolymerization activator; then adding the L-lactide or the D-lactide into the system, and introducing N 2 Vacuum pumping, repeating for three times, vacuum sealing, reacting at constant temperature for a certain time, cooling, dissolving the mixture in chloroform, precipitating with methanol for three times, and vacuum drying the product at 50deg.C for 12 hr to obtain polylactic acid block polymers PLLA-b-PBSO-b-PLLA and PDLA-b-PBSO-b-PDLA.
(2) And (3) adopting an internal mixer to blend the PLLA-b-PBSO-b-PLLA and PDLA-b-PBSO-b-PDLA by melting at 180 ℃ at 30Hz for 5min to prepare the PLLA-b-PBSO-b-PLLA/PDLA-b-PBSO-b-PDLA high temperature resistant polylactic acid block elastomer.
In order to make the hydroxyl-terminated polyester have the best chain flexibility to meet the requirement of being used as a soft block, thereby endowing the block polymer with better elasticity, and the molar ratio of succinic acid to diphenyl ether dicarboxylic acid is 1:1. This is because the glass transition temperature T of the prepared PBSO when the molar ratio of succinic acid monomer to diphenylether dicarboxylic acid monomer in PBSO is 1:1 g (19.7 ℃) is close to room temperature and is an amorphous polymer, providing good softness to the block polymer.
In order to achieve high heat resistance of the composite, it is further optimized that PLLA and PDLA hard block molecular weights in the PLLA-b-PBSO-b-PLLA and PDLA-b-PBSO-b-PDLA described in the step (1) are 4000 to 10000/mol. This is because the molecular weights of PLLA and PDLA hard blocks are moderately lower to favor SC crystal formation. When the molecular weight of PLLA and PDLA hard blocks is too low, the content of SC crystals formed is correspondingly low; when the molecular weight of PLLA and PDLA hard blocks is too high, ordered stacking of molecular chains between PLLA and PDLA is not favored, and correspondingly the content of SC crystals formed is low. Therefore, it is difficult to achieve high heat resistance of polylactic acid with too low or too high molecular weight. In addition, the reaction time required for synthesizing the polylactic acid block with higher molecular weight is longer. Therefore, from the aspects of material performance, synthesis efficiency and energy consumption cost, the invention discovers that the molecular weight of the polylactic acid block required for preparing the high-temperature-resistant block copolyester composite elastomer is 4000-10000/mol.
In order to realize high heat resistance of the polylactic acid block composite system, the step (2) is further optimized to blend 40% -60% of PLLA-b-PBSO-b-PLLA and 40% -60% of PLLA-b-PBSO-b-PLLA in the two components. The PLLA and PDLA molecular chains are orderly arranged between folding to form complete SC crystals, and the molecular arrangement structure is shown in figure 5. The formation of SC crystals is favored when the PLLA and PDLA block ratios are close to 1:1.
Further preferably, the blending temperature in step (2) is 180 ℃. In order to form SC crystals from PLLA and PDLA blocks and avoid excessive blending temperature and excessive blending time to degrade and break the polymer, the banburying temperature in the step (2) is preferably 180 ℃ and the banburying time is preferably 5min.
The invention needs to control the banburying temperature at 180 ℃, when the banburying temperature is lower, the viscosity of the system is high, the mixing effect of the two components is poor, and SC crystals are not formed; when the banburying temperature is too high, the breaking degradation of the carbon chain is caused. Through multiple experimental tests, the effect is best when the temperature is 180 ℃.
Compared with the prior art, the invention has the following beneficial effects:
1) The invention takes hydroxyl-terminated polyester HO-PBSO-OH as a soft segment and lactide ring-opening polymerization to form a polylactic acid hard segment, and the ABA polylactic acid segmented copolymer with a strict molecular structure can be obtained by the reaction mode. PBSO is selected as a soft block, and the prepared block copolyesters have biodegradability and temperature applicability.
2) The invention utilizes the PLLA block with low molecular weight and the PDLA block to blend to form SC crystal, so that a firmer crystallization hard segment is formed in a composite system, and the finally formed block copolyester product is a high-rebound biodegradable high polymer material, accords with the development trend of environment-friendly and resource-saving high polymer materials, and has important significance in the fields of thermoplastic, high-temperature resistant and high-rebound high polymer materials.
Drawings
FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of a PLLA-b-PBSO-b-PLLA polylactic acid block copolymer prepared in example 1 of the present invention.
FIG. 2 is a DSC curve of the temperature rise of the polylactic acid block copolymer prepared in comparative examples 1-4 of the present invention and comparative examples 1 and 2.
FIG. 3 is a stress-strain curve of the polylactic acid block copolymer prepared in comparative examples 1 to 2 and comparative examples 1 to 4 of the present invention.
FIG. 4 is a graph showing creep and creep recovery curves at 25℃and 160℃of the polylactic acid block copolymers prepared in comparative examples 1 to 4 and comparative examples 1 and 2 according to the present invention.
FIG. 5 is a schematic representation of the product of the present invention.
Detailed Description
The invention is further illustrated by the following examples, but the scope of the invention is not limited thereto:
example 1:
(1) 1, 4-butanediol (86.5 g), succinic acid (0.12 mol) (14.2 g) and diphenyl ether dicarboxylic acid (0.12 mol) (31.0 g) are added into a 500ml three-neck flask with a stirring device, a condensing device and a nitrogen protection device according to an alkyd ratio of 4:1; to a three-necked flask, 0.4g (0.5% by mole of the acid monomer) of tetrabutyl titanate catalyst was added dropwise. Opening condensed water, and introducing N 2 Heating to 180 ℃, and after the monomer is completely melted, stirring at constant temperature for esterification for 3-4 hours to complete the esterification reaction stage; and then removing the condensing device, replacing the condensing device with a vacuumizing device provided with a safety bottle, a wheat type vacuum meter and an oil pump, carrying out a polycondensation stage, heating to 220 ℃, continuously reacting for 3 hours, collecting a product at room temperature, dissolving the product with chloroform, precipitating with methanol, filtering and drying to obtain the purified hydroxyl-terminated polyester HO-PBSO-OH.
Adding 20g of hydroxyl-terminated polyester HO-PBSO-OH prepared in the above way, 10ml of toluene and 0.02g of stannous octoate catalyst (0.5% of the mass of the L-lactide) into a three-necked flask, and adding the mixture into N 2 Reacting for 4 hours at 80 ℃ under protection, closing nitrogen, vacuumizing, and removing toluene to obtain a prepolymerization activator; then 4g of L-lactide is added into a three-mouth bottle, and N is introduced 2 Vacuum-pumping, repeating for three times, vacuum-sealing, reacting at 130deg.C for 24 hr, cooling, dissolving the mixture in chloroform, precipitating with methanol for three times, and vacuum-drying the product at 50deg.CDrying for 12h to obtain the polylactic acid segmented copolymer PLLA-b-PBSO-b-PLLA.
And taking the dextrorotatory lactide as a raw material, and preparing the polylactic acid segmented copolymer PDLA-b-PBSO-b-PDLA under the same monomer proportion and synthesis process.
(2) Taking 16g PLLA-b-PBSO-b-PLLA and 24g PDLA-b-PBSO-b-PDLA, placing the mixture in an internal mixer at 180 ℃ and the rotating speed of 30Hz, and carrying out internal mixing for 5min to obtain the PLLA-b-PBSO-b-PLLA/PDLA-b-PBSO-b-PDLA polylactic acid block compound.
Example 2:
(1) 1, 4-butanediol (86.5 g), succinic acid (0.12 mol) (14.2 g) and diphenyl ether dicarboxylic acid (0.12 mol) (31.0 g) are added into a 500ml three-neck flask with a stirring device, a condensing device and a nitrogen protection device according to an alkyd ratio of 4:1; to a three-necked flask, 0.4g (0.5% by mole of the acid monomer) of tetrabutyl titanate catalyst was added dropwise. Opening condensed water, and introducing N 2 Heating to 180 ℃, and after the monomer is completely melted, stirring at constant temperature for esterification for 3-4 hours to complete the esterification reaction stage; and then removing the condensing device, replacing the condensing device with a vacuumizing device provided with a safety bottle, a wheat type vacuum meter and an oil pump, carrying out a polycondensation stage, heating to 220 ℃, continuously reacting for 4 hours, collecting a product at room temperature, dissolving the product with chloroform, precipitating with methanol, filtering and drying to obtain the purified hydroxyl-terminated polyester HO-PBSO-OH.
Adding 20g of hydroxyl-terminated polyester HO-PBSO-OH prepared in the above way, 10ml of toluene and 0.05g of stannous octoate catalyst (0.5% of the mass of the L-lactide) into a three-necked flask, and adding the mixture into N 2 Reacting for 4 hours at 80 ℃ under protection, closing nitrogen, vacuumizing, and removing toluene to obtain a prepolymerization activator; then 10g of L-lactide is added into a three-mouth bottle, and N is introduced 2 Vacuum pumping, repeating for three times, vacuum sealing, reacting at 130deg.C for 24 hr, cooling, dissolving the mixture in chloroform, precipitating with methanol for three times, and vacuum drying the product at 50deg.C for 12 hr to obtain polylactic acid block copolymer PLLA-b-PBSO-b-PLLA.
And taking the dextrorotatory lactide as a raw material, and preparing the polylactic acid segmented copolymer PDLA-b-PBSO-b-PDLA under the same monomer proportion and synthesis process.
(2) Taking 24g PLLA-b-PBSO-b-PLLA and 16g PDLA-b-PBSO-b-PDLA, placing the mixture in an internal mixer at 180 ℃ and the rotating speed of 30Hz, and carrying out internal mixing for 5min to obtain the PLLA-b-PBSO-b-PLLA/PDLA-b-PBSO-b-PDLA polylactic acid block compound.
Example 3:
(1) 1, 4-butanediol (86.5 g), succinic acid (0.12 mol) (14.2 g) and diphenyl ether dicarboxylic acid (0.12 mol) (31.0 g) are added into a 500ml three-neck flask with a stirring device, a condensing device and a nitrogen protection device according to an alkyd ratio of 4:1; to a three-necked flask, 0.4g (0.5% by mole of the acid monomer) of tetrabutyl titanate catalyst was added dropwise. Opening condensed water, and introducing N 2 Heating to 180 ℃, and after the monomer is completely melted, stirring at constant temperature for esterification for 3-4 hours to complete the esterification reaction stage; and then removing the condensing device, replacing the condensing device with a vacuumizing device provided with a safety bottle, a wheat type vacuum meter and an oil pump, carrying out a polycondensation stage, heating to 220 ℃, continuously reacting for 4 hours, collecting a product at room temperature, dissolving the product with chloroform, precipitating with methanol, filtering and drying to obtain the purified hydroxyl-terminated polyester HO-PBSO-OH.
Adding 20g of hydroxyl-terminated polyester HO-PBSO-OH prepared in the above way, 10ml of toluene and 0.02g of stannous octoate catalyst (0.5% of the mass of the L-lactide) into a three-necked flask, and adding the mixture into N 2 Reacting for 4 hours at 80 ℃ under protection, closing nitrogen, vacuumizing, and removing toluene to obtain a prepolymerization activator; then 4g of L-lactide is added into a three-mouth bottle, and N is introduced 2 Vacuum pumping, repeating for three times, vacuum sealing, reacting at 130deg.C for 24 hr, cooling, dissolving the mixture in chloroform, precipitating with methanol for three times, and vacuum drying the product at 50deg.C for 12 hr to obtain polylactic acid block copolymer PLLA-b-PBSO-b-PLLA.
And taking the dextrorotatory lactide as a raw material, and preparing the polylactic acid segmented copolymer PDLA-b-PBSO-b-PDLA under the same monomer proportion and synthesis process.
(2) 20g PLLA-b-PBSO-b-PLLA and 20g PDLA-b-PBSO-b-PDLA are taken and placed in an internal mixer for banburying for 5min at 180 ℃ and the rotating speed is 30Hz, so that the PLLA-b-PBSO-b-PLLA/PDLA-b-PBSO-b-PDLA polylactic acid block compound is prepared.
Example 4:
(1) 1, 4-butanediol (86.5 g), succinic acid (0.12 mol) (14.2 g) and diphenyl ether dicarboxylic acid (0.12 mol) (31.0 g) are added into a 500ml three-neck flask with a stirring device, a condensing device and a nitrogen protection device according to an alkyd ratio of 4:1; to a three-necked flask, 0.4g (0.5% by mole of the acid monomer) of tetrabutyl titanate catalyst was added dropwise. Opening condensed water, and introducing N 2 Heating to 180 ℃, and after the monomer is completely melted, stirring at constant temperature for esterification for 3-4 hours to complete the esterification reaction stage; and then removing the condensing device, replacing the condensing device with a vacuumizing device provided with a safety bottle, a wheat type vacuum meter and an oil pump, carrying out a polycondensation stage, heating to 220 ℃, continuously reacting for 3 hours, collecting a product at room temperature, dissolving the product with chloroform, precipitating with methanol, filtering and drying to obtain the purified hydroxyl-terminated polyester HO-PBSO-OH.
Adding 20g of hydroxyl-terminated polyester HO-PBSO-OH prepared in the above way, 10ml of toluene and 0.05g of stannous octoate catalyst (0.5% of the mass of the L-lactide) into a three-necked flask, and adding the mixture into N 2 Reacting for 4 hours at 80 ℃ under protection, closing nitrogen, vacuumizing, and removing toluene to obtain a prepolymerization activator; then 10g of L-lactide is added into a three-mouth bottle, and N is introduced 2 Vacuum pumping, repeating for three times, vacuum sealing, reacting at 130deg.C for 24 hr, cooling, dissolving the mixture in chloroform, precipitating with methanol for three times, and vacuum drying the product at 50deg.C for 12 hr to obtain polylactic acid block copolymer PLLA-b-PBSO-b-PLLA.
And taking the dextrorotatory lactide as a raw material, and preparing the polylactic acid segmented copolymer PDLA-b-PBSO-b-PDLA under the same monomer proportion and synthesis process.
(2) 20g PLLA-b-PBSO-b-PLLA and 20g PDLA-b-PBSO-b-PDLA are taken and placed in an internal mixer for banburying for 5min at 180 ℃ and the rotating speed is 30Hz, so that the PLLA-b-PBSO-b-PLLA/PDLA-b-PBSO-b-PDLA polylactic acid block compound is prepared.
Comparative example 1 and comparative example 2:
comparative example 1 and comparative example 2 are mainly different from example 2 in that: comparative example 1 is a single levorotatory polylactic acid block polymer and comparative example 2 is a single dextrorotatory polylactic acid block polymer, i.e., SC stereocomplex crystals are not present in the systems of comparative example 1 and comparative example 2.
(1) 1, 4-butanediol (86.5 g), succinic acid (0.12 mol) (14.2 g) and diphenyl ether dicarboxylic acid (0.12 mol) (31.0 g) are added into a 500ml three-neck flask with a stirring device, a condensing device and a nitrogen protection device according to an alkyd ratio of 4:1; to a three-necked flask, 0.4g (0.5% by mole of the acid monomer) of tetrabutyl titanate catalyst was added dropwise. Opening condensed water, and introducing N 2 Heating to 180 ℃, and after the monomer is completely melted, stirring at constant temperature for esterification for 3-4 hours to complete the esterification reaction stage; and then removing the condensing device, replacing the condensing device with a vacuumizing device provided with a safety bottle, a wheat type vacuum meter and an oil pump, carrying out a polycondensation stage, heating to 220 ℃, continuously reacting for 3 hours, collecting a product at room temperature, dissolving the product with chloroform, precipitating with methanol, filtering and drying to obtain the purified hydroxyl-terminated polyester HO-PBSO-OH.
Adding 20g of hydroxyl-terminated polyester HO-PBSO-OH prepared in the above way, 10ml of toluene and 0.05g of stannous octoate catalyst (0.5% of the quality of lactide) into a three-necked flask, and adding the mixture into N 2 Reacting for 4 hours at 80 ℃ under protection, closing nitrogen, vacuumizing, and removing toluene to obtain a prepolymerization activator; then 10g of L-lactide is added into a three-mouth bottle, and N is introduced 2 Vacuum pumping, repeating for three times, vacuum sealing, reacting at 130deg.C for 24 hr, cooling, dissolving the mixture in chloroform, precipitating with methanol for three times, and vacuum drying the product at 50deg.C for 12 hr to obtain the L-polylactic acid block copolymer PLLA-b-PBSO-b-PLLA of comparative example 1.
The D-lactide is used as a raw material, and the D-polylactic acid segmented copolymer PDLA-b-PBSO-b-PDLA of the comparative example 2 is prepared under the same monomer proportion and synthesis process.
The high temperature resistant polylactic acid block composite elastomer prepared in each example was tested and evaluated by the following method:
gel Permeation Chromatography (GPC): the number average molecular weight and the weight average molecular weight of the block copolyesters were measured using a gel permeation chromatograph from Waters 515-2414, usa, using tetrahydrofuran as the mobile phase.
Nuclear magnetic hydrogen spectrum: avance using Bruker in the united statesThe block copolyesteride chemical structure was analyzed by a III 400MHz nuclear magnetic resonance hydrogen spectrometer. With deuterated chloroform (CDCl) 3 ) Is a good copolyester solvent.
Differential scanning calorimetric analysis (DSC): testing with DSC-4000 model differential scanning calorimeter of German resistant, collecting 3-5mg sample, placing in crucible, and adding into N 2 The test is carried out under the condition of 40mL/min flow, the heating rate is 10 ℃/min, and the temperature range is 20-240 ℃.
Stretching at break: a Shenzhen Kai powerful WD-II 10 type electronic universal tester is adopted to measure according to GB/T1040-1992, and a stress-strain curve of the breaking process is obtained.
Creep recovery: samples were analyzed for creep and creep recovery properties using a Physica MCR 301 rotational rheometer from Anton Pear, germany, in transient mode, stress levels of 0.02MPa, creep times of 600s, and creep recovery times of 1800s at room temperature of 25℃and 160℃with sample specifications of 1 mm. Times.5 mm. Times.30 mm.
As can be seen from FIG. 1, the polylactic acid block copolymers prepared in comparative examples 1 and 2 have nuclear magnetic resonance hydrogen spectra. Wherein the structure containing the PBSO segment, δ=4.11 ppm (a) corresponds to the chemical shift of H on the carbon of the butanedioic acid unit near the oxygen atom, δ=1.71 ppm (b) corresponds to the chemical shift of H on the two carbons in the middle of the butanedioic acid unit, δ=2.62 ppm (c) corresponds to the chemical shift of H on the methylene carbon of the butanedioic acid; on the butanediol diphenylether dicarboxylic acid unit, δ=7.07 pp (g) corresponds to the chemical shift of H on the carbon close to the ether bond on the benzene ring of diphenylether dicarboxylic acid, δ=8.07 ppm (f) corresponds to the chemical shift of H on the carbonyl carbon on the benzene ring of diphenylether dicarboxylic acid, and furthermore δ=3.55 ppm (d) is the chemical shift of H on the methylene peak of the butanediol unit attached to the end of the macromolecular initiator. Meanwhile, the block structure of PLA also contains delta=5.20 ppm (k) which is the chemical shift of H on the methine of PLA, and delta=1.50 ppm (l) which is the chemical shift of H on the methyl of PLA. Thus, this example shows that triblock copolymer ester was successfully synthesized.
As can be seen from FIG. 2, the DSC temperature rise curves of the polylactic acid block copolymers prepared in examples 1 to 4, comparative example 1 and comparative example 2. Obvious endothermic peaks appear in DSC curves of the composite elastomers of examples 1 to 4 at around 160℃and higher temperatures (about 210 ℃) and have been reported in the literature to correspond to the crystal (HC) melting peaks of PLLA and PDLA blocks at around 160℃and the endothermic peak at 210℃is attributed to the melting peak of the SC crystal. It was revealed that the composite elastomers of examples 1 to 4 contained both HC crystals and SC composite stereocrystals. Whereas comparative examples 1 and 2 showed no absorption peak at 210℃indicating no SC crystals in comparative example 1.
As can be seen from FIG. 3, the stress-strain curves of the polylactic acid block copolymers prepared in examples 1 to 4, comparative example 1 and comparative example 2. Young's moduli of comparative example 1 and comparative example 2 were 3.02 and 3.41MPa, respectively, and elongation at break was as high as 1133% and 976%, respectively, with lower modulus and high elongation at break. Examples 1-4 have a moderate Young's modulus (< 15 MPa) and a high elongation at break (> 600%) because examples 1-4 contain both HC crystals and Complex Stereocrystals (SCs) as the rigid segments, and the PLLA-b-PBSO-b-PLLA and PDLA-b-PBSO-b-PDLA components in examples 3-4 have a mass ratio of 1:1, the system contains a large amount of SC, which is advantageous for the rebound resilience of the examples.
As can be seen from FIG. 4, the polylactic acid block copolymers prepared in examples 1 to 4, comparative example 1 and comparative example 2 have creep and creep recovery curves at 25℃and 160℃and it can be seen that examples 1 to 4 have higher high temperature resilience. By comparing the ratio α (ε/ε) of the residual strain after creep recovery (t=2400 s) to the initial strain (t=0 s) 0 ) To judge the restorability of the material, the smaller the alpha value is, the better the restorability is. The data are presented in Table 1. The α of examples 1-4, comparative example 1 and comparative example 2 were all increased at 160℃relative to 25 ℃. However, the curves for comparative example 1 and comparative example 2 are significantly more abrupt, with the alpha values for comparative example 1 and comparative example 2 being 1.12 and 1.08, respectively, at 25 ℃, and the alpha values for comparative example 1 and comparative example 2 being increased to 1.88 and 1.99, respectively, at 160 ℃. The alpha values of examples 1-4 were calculated in the same manner as 1.00, 0.80, 0.97 and 0.95, respectively, at 25 ℃; 1.20, 1.17, 0.77 and 0.73 respectively at 160 ℃. I.e., examples 1 to 4 have higher rebound resilience relative to comparative examples 1 and 2. This is due to the fact that at high temperatures single PLLA-b-PBSO-b-PLLA and PDLA-b-PBSO-bThe PLLA and PDLA blocks in PDLA melt, without rigid structures in the system; the SC crystal in the composite system is used as a hard segment, so that the material keeps good rebound resilience at 160 ℃.
Table 1 shows the weight average molecular weight data of the polylactic acid block copolymers prepared in comparative examples 1 to 2 and comparative examples 1 to 4 of the present invention.
Table 2 shows creep and creep recovery data at 25℃and 160℃for the polylactic acid block copolymers prepared in comparative examples 1 to 4 of the present invention and comparative examples 1 and 2.
TABLE 1
TABLE 2
Claims (9)
1. The high temperature resistant polylactic acid block elastomer is characterized by comprising two components of:
the chemical structural formula of the L-polylactic acid-b-poly (butylene succinate-co-diphenyl ether butylene diformate) ester-b-L-polylactic acid triblock copolymer, namely PLLA-b-PBSO-b-PLLA, is as follows:
the chemical structural formula of the tri-block copolymer of the dextrorotatory polylactic acid-b-poly (butylene succinate-co-diphenyl ether butylene diformate) ester-b-dextrorotatory polylactic acid, namely PDLA-b-PBSO-b-PDLA, is as follows:
2. a method for preparing the high temperature resistant polylactic acid block elastomer according to claim 1, which is characterized in that: the method comprises the following steps:
(1) Preparing hydroxyl-terminated polyester HO-PBSO-OH by taking 1, 4-butanediol, succinic acid and diphenyl ether dicarboxylic acid as raw materials and tetrabutyl titanate as a catalyst; then using HO-PBSO-OH as a macromolecular initiator, using L-lactide LLA or D-lactide DLA as a monomer, using stannous octoate as a catalyst, and preparing PLLA-b-PBSO-b-PLLA and PDLA-b-PBSO-b-PDLA by ring opening polymerization;
(2) PLLA-b-PBSO-b-PLLA and PDLA-b-PBSO-b-PDLA are subjected to melt blending to prepare the PLLA-b-PBSO-b-PLLA/PDLA-b-PBSO-b-PDLA high temperature resistant polylactic acid block elastomer.
3. The method for preparing the high temperature resistant polylactic acid block elastomer according to claim 2, which is characterized in that: the molar ratio of the alkyd in the step (1) is 4:1, and the molar ratio of the succinic acid to the diphenyl ether dicarboxylic acid is 1:1.
4. The method for preparing the high temperature resistant polylactic acid block elastomer according to claim 2, which is characterized in that: the molecular weight of the PBSO block in the PLLA-b-PBSO-b-PLLA and the PDLA-b-PBSO-b-PDLA in the step (1) is 20000 to 50000g/mol.
5. The method for preparing the high temperature resistant polylactic acid block elastomer according to claim 2, which is characterized in that: the molecular weight of the single PLLA block and the single PDLA block in the PLLA-b-PBSO-b-PLLA and the single PLLA block in the PDLA-b-PBSO-b-PDLA in the step (1) is 4000-10000g/mol.
6. The method for preparing the high temperature resistant polylactic acid block elastomer according to claim 2, which is characterized in that: in the step (2), the PLLA-b-PBSO-b-PLLA accounts for 40% -60% and the PLLA-b-PBSO-b-PLLA accounts for 60% -40%.
7. The method for preparing the high temperature resistant polylactic acid block elastomer according to claim 2, which is characterized in that: in the step (2), the materials are melted and blended in an internal mixer, the internal mixing temperature is 180 ℃, and the internal mixing time is 5min.
8. The method for preparing the high temperature resistant polylactic acid block elastomer according to claim 2, which is characterized in that: the amount of tetrabutyl titanate used in step (1) was 0.5% of the molar amount of the acid monomer.
9. The method for preparing the high temperature resistant polylactic acid block elastomer according to claim 2, which is characterized in that: the amount of stannous octoate is 0.5% of the mass of the levorotatory lactide LLA or the dextrorotatory lactide DLA lactide.
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