Manufacturing method of succinic acid polyol ester and polycondensate thereof

Abstract

The invention provides a manufacturing method of succinic acid polyol ester and polycondensate thereof. The manufacturing method comprises the following steps: esterifying maleic anhydride and polyol to prepare maleic acid polyol ester (GM); the preparation method comprises the following three steps: preparing polysuccinic acid polyol ester (GS) through GM hydrogenation, and carrying out polycondensation on the GS or carrying out copolycondensation on the GS and a third monomer to prepare polysuccinate (PGS or PGSX) or carrying out block copolymerization on the polysuccinic acid polyol ester and other polymers (PQD) to prepare a block copolymer (PGS-co-PQD) of the polysuccinic acid polyol ester. Compared with the existing PBS synthesis process, the method has the advantages that GS and the polycondensate thereof can be obtained only through three-step reaction from maleic anhydride, the steps of synthesis, separation and purification of succinic acid and succinic acid derivative succinic anhydride or succinic acid monohydric alcohol ester monomers are omitted, the process flow is greatly simplified, material consumption, energy consumption and device investment are low, the utilization rate of raw materials is high, and the raw materials are low in price and easy to obtain; the production cost is low, the process is green and efficient, and the market competitiveness of the polysuccinate material is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of biodegradable polyester precursors and polyester materials, and particularly relates to a method for manufacturing a succinic acid polyol ester and its condensate. Background Art

[0002] Synthesizing intermediates and polymers with green and efficient raw material routes has become the development direction in the chemical industry and the field of high-tech materials. Replacing traditional plastics such as polyolefin PP and polyester PET with biodegradable plastics such as polybutylene succinate (PBS), copolyesters of butylene succinate and a third monomer (PBSX), and block copolymers of polybutylene succinate and other polymers (PQD) (PBS-co-PQD) has become the mainstream trend of social development.

[0003] Currently, for the synthesis of polybutylene succinate-based polyester materials (PBS / PBSX), high-purity monomers such as succinic acid, succinic anhydride, or lower alkyl succinates are first prepared through maleic anhydride chemical synthesis, biomass fermentation synthesis, and separation and purification, that is: maleic anhydride is hydrogenated to prepare succinic anhydride, succinic anhydride is then hydrolyzed to prepare succinic acid or esterified with lower alkanols to prepare lower alkyl succinates, or maleic anhydride is esterified with alkanols to prepare lower alkyl maleates, lower alkyl maleates are further hydrogenated to prepare lower alkyl succinates, and lower alkyl succinates are further hydrolyzed to prepare succinic acid, or succinic acid is synthesized by biomass fermentation, and succinic acid is then dehydrated to prepare succinic anhydride or esterified with lower alkanols to prepare lower alkyl succinates; then, pure monomers such as succinic acid, succinic anhydride, or lower alkyl succinates and saturated diols or diols and a third monomer are used to synthesize succinic acid diol esters through direct esterification, ring-opening esterification, or transesterification reactions; finally, the succinic acid diol esters are further prepared through multiple-step negative pressure polycondensation reactions.

[0004] For example, patents CN 112694602 B and CN 110563933 B provide methods for producing PBS using maleic anhydride as a raw material. In the former, maleic anhydride is first hydrogenated to prepare succinic anhydride, and then succinic anhydride is esterified and refined with a lower aliphatic monohydric alcohol to prepare diethyl succinate. In the latter, maleic anhydride is first esterified with a lower aliphatic monohydric alcohol to prepare dimethyl maleate, and then dimethyl maleate is hydrogenated and refined to prepare diethyl succinate. Then, diethyl succinate is synthesized with 1,4-butanediol through transesterification and polycondensation reactions to obtain PBS. Another example is that patent CN 114920913 B provides a method for catalytic conversion of maleic anhydride to prepare PBS. Maleic anhydride is dissolved in tetrahydrofuran to prepare a maleic anhydride solution, and then hydrogenated to generate succinic anhydride and γ-butyrolactone. The γ-butyrolactone solution in tetrahydrofuran and succinic anhydride are separated. The γ-butyrolactone solution in tetrahydrofuran is further hydrogenated to obtain a 1,4-butanediol solution in tetrahydrofuran, and 1,4-butanediol and tetrahydrofuran are separated. Finally, succinic anhydride and 1,4-butanediol are subjected to ring-opening esterification and polycondensation reactions to produce the product PBS. Another example is that patent CN 106366297 B discloses a preparation method for the entire PBS industrial chain. N-butane obtained by rectifying C4 fractions is used as a raw material to produce liquid-phase maleic anhydride, and then liquid-phase maleic anhydride is used as a raw material to produce succinic anhydride. Then, succinic anhydride is subjected to ring-opening esterification with 1,4-butanediol to prepare the precursor butanediol succinate, and finally butanediol succinate is vacuum-polycondensed to obtain PBS.

[0005] It can be seen that the synthesis process flow of polybutylene succinate polyesters (PBS / PBSX) is long. Especially, the reaction and separation steps for preparing monomers are numerous and the operation is cumbersome, increasing the equipment investment, and the raw material and energy consumption are high. Therefore, it is imperative to develop a large-scale production technology for succinic acid ester polyesters with abundant raw material sources and supplies, a green and environmentally friendly synthesis route, a short and efficient process flow, low production costs, and high product quality. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a low-cost preparation method for polybutylene succinate biodegradable materials with rich raw material sources, a simple process route, and an efficient production process.

[0007] To achieve the above purpose, the technical solution of the present invention is specifically as follows:

[0008] A method for manufacturing a succinic acid polyol ester and its condensate, comprising the following steps:

[0009] A1. After mixing the raw materials maleic anhydride and polyol in a molar ratio of 1.00:(0.50 - 2.50), they are fed into an esterification reactor filled with an acid catalyst, and under a reaction temperature of 40 - 180°C, a reaction pressure of 0.01 - 1.00 MPa, and a residence time of 0.10 - 5.00 h, a ring-opening esterification reaction of maleic anhydride is carried out to prepare a maleic acid polyol ester;

[0010] A2. Directly feed the maleic acid polyol ester material obtained in step A1 into a hydrogenation reactor filled with a hydrogenation catalyst, and carry out the double-bond hydrogenation of the maleic acid polyol ester to prepare a succinic acid polyol ester at a feed temperature of 40 - 180°C, a hydrogen pressure of 0.20 - 5.00 MPa, a hydrogen-to-ester molar ratio of 2 - 50, and a residence time of 0.25 - 5.00 h.

[0011] A3. In the presence of a polymerization catalyst, carry out polycondensation on the succinic acid polyol ester material obtained in step A2 to prepare a poly(succinic acid polyol ester) (PGS), or carry out co-polycondensation with a third monomer to prepare a succinic acid polyol - third monomer copolyester (PGSX), or carry out block copolymerization of a prepolymer of the succinic acid polyol ester with other polymers (PQD) to prepare a block copolymer of poly(succinic acid polyol ester) (PGS-co-PQD).

[0012] Among them, the polyol is selected from at least one of aliphatic, aromatic or heterocyclic diols or polyols with more than two hydroxyl groups; the third monomer is selected from one or more of polyacids, polyanhydrides, polyesters, polyols, polyol ethers, hydroxy acids, hydroxy acid esters, lactides or lactones; the polymer PQD is selected from one or more of polyethers, polyesters, polyvinyl alcohols or polycarbonates; the acid catalyst is selected from liquid acid catalysts or / and solid acid catalysts; the hydrogenation catalyst is selected from at least one of catalysts with a porous support material loaded with transition metals or / and noble metals.

[0013] Further, in step A1, the esterification reactor is selected from a tower kettle reactor, a pipe reactor or a fixed bed reactor, and the reaction mode is batch or continuous reaction; the process conditions for the esterification reaction are: the molar ratio of maleic anhydride to polyol is 1.00:(0.75 - 2.00), the reaction temperature is 55 - 150°C, the reaction pressure is 0.05 - 0.50 MPa, and the residence time is 0.25 - 3.00 h.

[0014] Preferably, the process conditions for the esterification reaction are: the molar ratio of maleic anhydride to polyol is 1.00:(1.00 - 1.75), the reaction temperature is 70 - 130°C, the reaction pressure is 0.09 - 0.25 MPa, and the residence time is 0.50 - 2.00 h.

[0015] More preferably, the process conditions for the esterification reaction are: the molar ratio of maleic anhydride to polyol is 1.00:(1.05 - 1.50), the reaction temperature is 80 - 120°C, the reaction pressure is 0.10 - 0.20 MPa, and the residence time is 0.75 - 1.50 h.

[0016] Further, in step A1, the liquid acid catalyst is selected from at least one of methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid (PTSA), fluorosulfonic acid, trifluoromethanesulfonic acid (TfOH), bis(trifluoromethanesulfonyl)imide (TFSI), trifluoromethanesulfonate or bis(trifluoromethanesulfonyl)imide salt, and the dosage is 0.02-2.00 wt% of the total liquid feed;

[0017] Preferably, the liquid acid catalyst is selected from PTSA, TfOH, TFSI, or trifluoromethanesulfonate or bis(trifluoromethanesulfonyl)imide salt of Al, Cu, Fe, Ti, Zr, La, Ce, Sm or Nd, and the dosage is 0.05-1.00 wt% of the total liquid feed;

[0018] Further, in step A1, the solid acid catalyst is selected from at least one of acidic oxides, heteropolyacids and their salts, solid superacids, hydrogen-type molecular sieves or hydrogen-type cation exchange resins. When using a kettle reactor, the dosage is 1.0-10.0 wt% of the total liquid feed;

[0019] Preferably, the solid acid catalyst is γ-Al 2 O 3 、SiO 2 -Al 2 O 3 、Nb 2 O 5 、H 3 PMo 12 O 40 、H 3 PW 12 O 40 、Cs 2.5 H 0.5 PW 12 O 40 、WO 3 / ZrO 2 、MoO 3 / TiO 2 、SO 4 2- / TiO 2 -La 2 O 3 、SO 4 2- / ZrO 2 、HM、Hβ、HZSM-5、HZSM-11、HMCM-22、HMCM-49、Amberlyst-15、Amberlyst-35、D-72 or Nafion, and when using a kettle reactor, the dosage is 2.0-7.5 wt% of the total feed;

[0020] More preferably, the solid acid catalyst is γ-Al2 O 3 、H 3 PW 12 O 40 、Cs 2.5 H 0.5 PW 12 O 40 、WO 3 / ZrO 2 、HM, HZSM-5, HMCM-22 or Amberlyst-15, and when using a kettle reactor, the dosage is 3.0 - 5.5 wt% of the total feed amount.

[0021] Further, the esterification reactor is selected from an intermittent or continuous kettle reactor, or a tubular reactor with a liquid acid catalyst, or a fixed bed reactor with a solid acid particle catalyst.

[0022] Further, the esterification reactor is an intermittent or continuous kettle reactor with an internal reflux fractionating column, or a tubular reactor with a liquid acid catalyst, or a trickle bed isothermal or adiabatic reactor with a solid acid particle catalyst.

[0023] Further, in step A2, the hydrogenation reactor is selected from a kettle reactor or a fixed bed reactor, and the reaction mode is intermittent or continuous. When a kettle reactor is selected, the dosage of the hydrogenation catalyst is 0.5 - 5.0 wt% of the feed amount of the maleic acid polyol ester, preferably 1.0 - 3.0 wt%;

[0024] The process conditions for the double bond hydrogenation reaction of the maleic acid polyol ester are: feed temperature 50 - 150 °C, hydrogen pressure 0.50 - 3.00 MPa, hydrogen - ester molar ratio 5 - 40, residence time 0.50 - 3.00 h;

[0025] Preferably, the process conditions for the double bond hydrogenation reaction of the maleic acid polyol ester are: feed temperature 60 - 120 °C, hydrogen pressure 0.75 - 2.50 MPa, hydrogen - ester molar ratio 8 - 30, residence time 0.75 - 2.5 h;

[0026] More preferably, the process conditions for the double bond hydrogenation reaction of the maleic acid polyol ester are: feed temperature 70 - 100 °C, hydrogen pressure 1.00 - 2.00 MPa, hydrogen - ester molar ratio 10 - 20, residence time 1.00 - 2.00 h.

[0027] Further, the hydrogenation reactor is selected from an intermittent kettle reactor, a slurry bed reactor or a trickle bed reactor, and the trickle bed reactor includes a trickle bed isothermal reactor and a trickle bed adiabatic reactor.

[0028] Further, in step A2, the hydrogenation catalyst is selected from activated carbon, SiO 2, γ-Al 2 O 3 , θ-Al 2 O 3 , SiO 2 -Al 2 O 3 , TiO 2 , ZrO 2 , at least one of HM, HHEU, Hβ, HZSM-5, HZSM-22, HMCM-22, HMCM-41, HMCM-48, HMCM-49, HMCM-56, SBA-15, ZEO-1 or KIT-6 loaded with a single metal or a bimetal of Ni, Cu, Ru, Pd or Pt; in the hydrogenation catalyst, the loading amount of Ni or Cu as the active component is 2-30%, or the loading amount of Ru is 0.5-10.0 wt%, or the loading amount of Pd or Pt is 0.05-5.0 wt%;

[0029] Preferably, the hydrogenation catalyst is selected from activated carbon, SiO 2 , γ-Al 2 O 3 , TiO 2 , ZrO 2 , HM, Hβ, HZSM-5, HMCM-22, HMCM-41 or SBA-15 loaded with a single metal of Ni, Cu, Ru, Pd or Pt or a bimetal of their combinations, wherein the loading amount of Ni or Cu as the active component is 3-20%, or the loading amount of Ru is 1.0-7.5 wt%, or the loading amount of Pd or Pt is 0.1-2.0 wt%;

[0030] More preferably, the hydrogenation catalyst is selected from activated carbon, SiO 2 , γ-Al 2 O 3 , HM, HZSM-5, HMCM-22, HMCM-41 or SBA-15 loaded with Ni, Pd, Pt, Ni-Cu, Pd-Ni or Pd-Ru catalysts, wherein the loading amount of Ni or Cu as the active component is 5-10%, or the loading amount of Ru is 2.0-5.0 wt%, or the loading amount of Pd or Pt is 0.2-1.0 wt%.

[0031] Further, the process of step A3 includes the following steps: adding a polymerization catalyst or a polymerization catalyst and a third monomer to the succinic acid polyol ester material prepared in step A2, stirring evenly, and then feeding it into an oligomerization reactor for a polycondensation reaction under reduced pressure to prepare an oligomer; then feeding the oligomer into a prepolymerization reactor for a negative pressure prepolycondensation reaction to prepare a prepolymer; finally, feeding the prepolymer into a final polymerization reactor, or mixing the prepolymer with other polymer PQD evenly and then feeding it into the final polymerization reactor for a vacuum final polycondensation reaction to obtain PGS or PGSX or PGS-co-PQD.

[0032] Further, in step A3, the polymerization catalyst is selected from compounds containing titanium, antimony or germanium; preferably at least one of titanium chloride, titanium butoxy chloride, tetraalkyl titanate, tetra-hydroxyalkyl titanate or dialkylene glycol titanate; more preferably at least one of tetrabutyl titanate, tetra-hydroxybutyl titanate, diethylene glycol titanate or dibutylene glycol titanate.

[0033] Further, in step A3, the dosage of the polymerization catalyst is 0.01-0.25 wt% of the succinic acid polyol ester material; preferably 0.02-0.15 wt%; more preferably 0.03-0.08 wt%.

[0034] Further, in step A3, the operating conditions for the oligomerization reaction are: temperature 150-200 °C, pressure 50-100 kPa, and material residence time 20-60 min; preferably temperature 160-180 °C, pressure 70-90 kPa, and material residence time 30-45 min.

[0035] Further, in step A3, the operating conditions for the prepolycondensation reaction are: temperature 180-230 °C, pressure 1-50 kPa, and material residence time 20-60 min; preferably temperature 190-210 °C, pressure 5-30 kPa, and material residence time 30-45 min.

[0036] Further, in step A3, the operating conditions for the final polycondensation reaction are: temperature 200-260 °C, pressure 10-200 Pa, and material residence time 60-180 min; preferably temperature 220-240 °C, pressure 50-90 Pa, and material residence time 90-150 min.

[0037] Further, when the target product is the succinic acid polyol - third monomer copolyester PGSX, a third monomer is added in step A3, and the molar ratio of the third monomer to maleic anhydride is 0.05-1.0; or,

[0038] When the target product is a block copolymer PGS-co-PQD of poly (succinic acid polyol ester), polymer PQD is added in step A3, and the weight ratio of the polymer PQD to the prepolymer is (10-30):(70-90).

[0039] Further, the polyol is selected from one or more of C 2 -C 22 aliphatic polyols, C 8 -C 16 aromatic polyols or C 4 -C 10 heterocyclic polyols;

[0040] Preferably, the polyol is selected from one or more of 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol (BDO), 1,5-pentanediol, 1,6-hexanediol (HDO), 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, dipropylene glycol, butenediol, butynediol, 2-methyl-1,3-propanediol, neopentyl glycol, trimethylolethane, trimethylolpropane (TMP), pentaerythritol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol (CHDM), o-phthalyl alcohol, m-phthalyl alcohol, p-benzenedimethanol (BDM), 2,5-furandimethanol (FDM), 2,6-pyranedimethanol or 2,5-thiophenedimethanol.

[0041] Further, the third monomer is selected from C 2 -C 22 aliphatic polycarboxylic acids, C 8 -C 16 aromatic polycarboxylic acids or C 4 -C 10 heterocyclic polycarboxylic acids, or cyclic anhydrides or esters of these polycarboxylic acids; C 2 -C 22 aliphatic polyols, C 8 -C 16 aromatic polyols or C 4 -C 10 heterocyclic polyols, or cyclic ethers of these polyols; C 2 -C 10 hydroxy fatty acids or their esters, lactides or lactones;

[0042] Preferably, the third monomer is selected from methylsuccinic acid, 1,5-pentanedioic acid, 1,6-hexanedioic acid, 1,10-decanedioic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,5-furandicarboxylic acid or its methyl ester, methylsuccinic anhydride, glutaric anhydride, methylglutaric anhydride, phthalic anhydride, trimellitic anhydride or pyromellitic dianhydride; ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, butenediol, butynediol, 2-methyl-1,3-propanediol, neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol, erythritol, sorbitol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, terephthalyl alcohol or 2,5-furandimethanol, ethylene oxide, propylene oxide, epichlorohydrin, tetrahydrofuran, furan, tetrahydrofurfuryl alcohol, furfuryl alcohol, pyran or tetrahydropyran; glycolic acid, lactic acid, 3-hydroxypropionic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 5-hydroxypentanoic acid, 6-hydroxyhexanoic acid or their methyl esters, glycolide, lactide, β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone or ε-caprolactone;

[0043] More preferably, the third monomer is selected from 1,5-pentanedioic acid, 1,6-hexanedioic acid, 1,10-decanedioic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 2,5-furandicarboxylic acid or its dimethyl ester, methylsuccinic anhydride, glutaric anhydride, methylglutaric anhydride; ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, butenediol, butynediol, neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, 1,4-cyclohexanedimethanol, terephthalyl alcohol or 2,5-furandimethanol, ethylene oxide, propylene oxide; glycolic acid, lactic acid, 3-hydroxypropionic acid, 4-hydroxybutyric acid or their methyl esters, glycolide, lactide, γ-butyrolactone, δ-valerolactone or ε-caprolactone.

[0044] Furthermore, the polymer PQD is selected from one of polyethers, polyesters, polyvinyl alcohols or polycarbonates with a molecular weight of 150 to 2000;

[0045] Preferably, the polymer PQD is selected from polyethylene glycol (PEG), polypropylene glycol (PPG), or polytetramethylene glycol (PTMG) with a molecular weight of 200 to 800, polyethylene glycol succinate diol (PES), polypropylene glycol succinate diol (PPS), polybutylene glycol succinate diol (PBS), polybutylene adipate diol (PBA), polyethylene terephthalate diol (PET), or polybutylene terephthalate diol (PBT) with a molecular weight of 300 to 1000, polyglycolic acid (PGA), polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutyrolactone (PGL), or polycaprolactone (PCL) with a molecular weight of 200 to 1000, polyvinyl alcohol (PVA) with a molecular weight of 150 to 800, poly(ethylene carbonate) (PPE), or poly(propylene carbonate) (PPC) with a molecular weight of 200 to 1000;

[0046] More preferably, the polymer PQD is selected from PEG, PPG, or PTMG with a molecular weight of 200 to 400, PES, PPS, PBS, PBA, PET, or PBT with a molecular weight of 300 to 600, PGA, PLA, PHA, PGL, or PCL with a molecular weight of 300 to 600, PVA with a molecular weight of 200 to 400, PPE, or PPC with a molecular weight of 300 to 600.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] (1) The present invention uses maleic anhydride, an industrial product with rich sources and low prices, as the starting material, prepares maleic acid polyol ester through ring-opening esterification, directly performs double-bond hydrogenation on the esterification product without separation and purification to prepare succinic acid polyol ester, and directly performs negative-pressure polycondensation on the hydrogenation product without separation and purification to obtain poly(succinic acid polyol ester) materials. It can be seen that the raw materials of the present invention are cheap and easily available, with low material and energy consumption and low production cost.

[0049] (2) The process route and process of the present invention are short. Starting from maleic anhydride, poly(succinic acid polyol ester) can be synthesized through only 3 consecutive reaction steps of ring-opening esterification, double-bond hydrogenation, and condensation polymerization. For the existing process, since it is necessary to prepare pure monomers such as succinic acid, succinic anhydride, or dialkyl succinate, at least 4 reaction and separation steps are required to synthesize polybutylene succinate (PBS / PBSX) starting from maleic anhydride, and some even require 9 reaction and separation steps. Therefore, the process flow of the present invention is short, the equipment investment is low, and the efficiency and total yield are high.

[0050] (3) The catalyst for the maleic anhydride esterification and double bond hydrogenation reactions of the present invention has high activity and mild process conditions, with high conversion rates and selectivities for the esterification and hydrogenation reactions. In addition, due to the adoption of the maleic anhydride ring-opening esterification reaction process, compared with the direct esterification of maleic acid or the transesterification process of maleic acid diester, the ring-opening esterification reaction rate is fast and the amount of small molecule by-products such as water generated is reduced by half, and the product yield is high. Obviously, the present invention has low raw material consumption, a cleaner and more efficient process, and reduces the environmental protection treatment cost.

[0051] (4) The product scheme of the present invention is flexible and diverse. Starting from maleic anhydride, through esterification, hydrogenation and polycondensation reactions, it is possible to produce polyglycol succinate di-block copolymer PGS, or polyglycol succinate - third monomer ter-copolymer PGSX, or block co-polymer PGS-co-PQD of polyglycol succinate and other polymers. Therefore, the product scheme of the present invention is flexible and the product variety can be adjusted at any time to meet the market demand. Detailed implementation manners

[0052] The following further elaborates the present invention in combination with specific embodiments. It should be noted that the embodiments described in this part are only a part of the present invention, rather than all embodiments. In view of this, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present invention.

[0053] Symbol description: GM is maleic acid polyol ester, GS is succinic acid polyol ester, PGS is polyglycol succinate, PGSX is succinic acid polyol - third monomer copolyester, PGS-co-PQD is block copolymer of polyglycol succinate and other polymer PQD; MMM is monomethyl maleate, DMM is dimethyl maleate, MMS is monomethyl succinate, DMS is dimethyl succinate, BS is butanediol succinate, PBS is polybutylene succinate; PTSA is p-toluenesulfonic acid, TfOH is trifluoromethanesulfonic acid, TFSI is bis(trifluoromethanesulfonyl)imide, TfOM is trifluoromethanesulfonate, MTFSI is bis(trifluoromethanesulfonyl)imide salt; HPA is H 3 PW 12 O 40 , CsHPA is Cs 2.5 H 0.5 PW 12 O 40 , CQA is WO 3 / ZrO 2 , TBT is tetrabutyl titanate.

[0054] Calculation description:

[0055] Conversion rate of maleic anhydride esterification (mol%) = (maleic anhydride feed amount - maleic anhydride residue amount) / maleic anhydride feed amount × 100;

[0056] GM selectivity (mol%) = amount of GM produced / (amount of maleic anhydride fed - amount of maleic anhydride remaining) × 100;

[0057] GM hydrogenation conversion rate (mol%) = amount of GM consumed / amount of GM fed × 100;

[0058] GS selectivity (mol%) = amount of GS produced / amount of GM consumed × 100;

[0059] Polyester feed yield (wt%) = weight of product polyester / (weight of maleic anhydride fed + weight of polyol fed + weight of hydrogen consumed + weight of third monomer or polymer PQD fed) × 100;

[0060] Effective polyester yield (wt%) = weight of product polyester / (weight of maleic anhydride + weight of polyol + weight of hydrogen consumed + weight of third monomer or polymer PQD - weight of recycled raw materials) × 100.

[0061] Examples 1 - 8

[0062] Preparation of succinic acid polyol ester (GS) by esterification and hydrogenation of maleic anhydride and its polycondensation to synthesize PGS

[0063] A1. Ring-opening esterification of maleic anhydride and polyol to prepare maleic acid polyol ester (GM): According to the polyol raw materials, acid catalysts, reactor forms and reaction process conditions shown in Table 1, mix the polyol and maleic anhydride at an alcohol - anhydride molar ratio of 1.00 - 1.75:1.00, and feed it into a reactor filled with an acid catalyst. Carry out the ring-opening esterification reaction of maleic anhydride to prepare GM at a reaction temperature of 85 - 150 °C, a reaction pressure of 0.09 - 0.25 MPa, and a residence time of 0.50 - 2.00 h. Among them, the acid catalysts used are p-toluenesulfonic acid (PTSA), trifluoromethanesulfonic acid (TfOH), aluminum trifluoromethanesulfonate (TfOAl), bis(trifluoromethanesulfonyl)imide (TFSI), samarium bis(trifluoromethanesulfonyl)imide (SmTFSI), H 3 PW 12 O 40 / SiO 2 (HPA / SiO 2 )、WO 3 / ZrO 2 (CQA) or HM. The reactor is selected from a continuous stirred-tank reactor with an internal reflux fractionating column, or a tubular reactor with a liquid acid catalyst, or a trickle-bed adiabatic reactor with a solid acid particle catalyst. The reaction results are shown in Table 1.

[0064] Table 1 Reaction process conditions and results of preparing maleic acid polyol ester (GM) by ring-opening esterification in Examples 1 - 8

[0065]

[0066]

[0067] A2. Preparation of polyol succinate (GS) by selective hydrogenation of polyol maleate (GM): The GM material obtained from the batch reactor using a liquid acid catalyst, the tubular reactor in step A1, or the trickle bed reactor using a solid acid particle catalyst is directly fed into the reactor filled with a hydrogenation catalyst; for the GM material obtained from the batch reactor using a solid acid catalyst, it is first fed into a filter to recover the catalyst, and then the liquid material is fed into the hydrogenation reactor. The hydrogenation reaction is carried out at a feed temperature of 60 - 100 °C, a hydrogen pressure of 0.75 - 2.00 MPa, a hydrogen-to-ester molar ratio of 8 - 30, and a residence time of 0.50 - 2.00 h to hydrogenate the double bond of GM to prepare GS. Among them, the hydrogenation catalyst is 1.0 wt% Pd / C, 0.5 wt% Pd / SiO 2 、0.5 wt% Pd / γ - Al 2 O 3 、0.3 wt% Pd / HM or 0.3 wt% Pd / SBA - 15. The reactor uses a slurry bed (at this time, the catalyst addition amount is 2.0 wt% of the GM feed amount) or a trickle bed adiabatic reactor. The hydrogenation reaction material is subjected to gas-liquid separation, and hydrogen is recycled. The liquid material using the trickle bed reactor is directly used as a polyester precursor, while the liquid material of the slurry bed reactor after filtering to recover the catalyst is used as a polyester precursor. The hydrogenation catalysts, reactor forms, reaction process conditions, and reaction results corresponding to each example are listed in Table 2.

[0068] Table 2 Reaction process conditions and results for the hydrogenation of polyol maleate (GM) to polyol succinate (GS)

[0069]

[0070] A3. Preparation of polyglycol succinate (PGS) by polycondensation of glycol succinate (GS): Tetrabutyl titanate (TBT) as a polymerization catalyst was added to the precursor GS material obtained in step A2. After stirring evenly, it was fed into an oligomerization reactor for vacuum polycondensation to prepare an oligomer. Then the oligomer was fed into a prepolymerization reactor for negative pressure polycondensation to prepare a prepolymer. Finally, the prepolymer was fed into a final polycondensation reactor for vacuum final polycondensation to obtain PGS. Among them, the addition amount of TBT was 0.03 - 0.08% of the feed weight; the oligomerization reaction temperature was 160 - 180 °C, the pressure was 70 - 90 kPa, and the residence time of the material was 30 - 60 min; the prepolymerization reaction temperature was 190 - 210 °C, the pressure was 5 - 30 kPa, and the residence time of the material was 30 - 45 min; the final polycondensation reaction temperature was 210 - 260 °C, the pressure was 50 - 90 Pa, and the residence time of the material was 90 - 150 min. The gaseous materials in the polycondensation reaction (oligomerization, prepolymerization, and final polycondensation) were collected. After distilling and removing low-boiling substances such as water, the recycled polyol was used in step A1 for the ring-opening esterification of maleic anhydride to prepare GM. The catalyst dosage, reaction process conditions, reaction results, and polyester parameters corresponding to each example are listed in Tables 3 and 4.

[0071] Table 3 Reaction process conditions for the polycondensation of glycol succinate (GS) to synthesize PGS

[0072]

[0073] Table 4 Polymerization catalyst dosage, yield of polyester PGS, and its corresponding parameters

[0074]

[0075] Comparative Example 1

[0076] Preparation of monomer succinic anhydride by hydrogenation of maleic anhydride and ring-opening esterification / polycondensation of it with BDO to synthesize PBS

[0077] 1) Hydrogenation and refining of maleic anhydride to prepare succinic anhydride: Maleic anhydride was dissolved in γ-butyrolactone to prepare a solution with a maleic anhydride concentration of 20 wt%, and it was fed into a trickle-bed hydrogenation reactor filled with 0.5 wt% Pd / Al 2 O 3 catalyst. The hydrogenation reaction was carried out at a reaction temperature of 60 °C, a hydrogen pressure of 1.0 MPa, a hydrogen-to-anhydride molar ratio of 20, and a weight hourly space velocity of 0.5 h -1 for the maleic anhydride solution. The reaction materials were subjected to gas-liquid separation, and hydrogen was recycled. The liquid product was separated by distillation to obtain monomer succinic anhydride with a purity greater than 99.5 wt%.

[0078] 2) Preparation of butylene succinate (BS) by ring-opening esterification of succinic anhydride: The monomers succinic anhydride and BDO were mixed into a pulp at a molar ratio of 1.00:1.30, and PTSA, an esterification catalyst accounting for 1.0 wt% of the total weight of succinic anhydride and BDO, was added. The esterification reaction was carried out under atmospheric pressure with distillation for 45 min at a temperature of 160 °C, and then the esterification reaction was carried out under reduced pressure with distillation for 30 min at a temperature of 180 °C and a pressure of 90 kPa to obtain the precursor BS.

[0079] 3) Preparation of poly(butylene succinate) (PBS) by polycondensation of BS: To the precursor BS, 0.08 wt% of the polymerization catalyst TBT based on the weight of the BS feed was added. The polycondensation reaction was carried out under negative pressure for 60 min at a temperature of 210 °C and a pressure of 30 kPa, and then under vacuum for 150 min at a temperature of 240 °C and a pressure of 50 Pa to obtain PBS. The gaseous materials in the polycondensation reaction were collected. After distilling off water and tetrahydrofuran, the recovered BDO was recycled for use in step 2) of the preparation of BS by ring-opening esterification of succinic anhydride. The polycondensation reaction conditions, results, and polyester parameters are shown in Tables 3 and 4.

[0080] Comparative Example 2

[0081] Preparation of monomer succinic acid by hydrogenation / hydrolysis of maleic anhydride and its esterification and polycondensation with BDO to prepare PBS

[0082] 1) Hydrogenation and purification of maleic anhydride to prepare succinic anhydride: The same as Comparative Example 1.

[0083] 2) Hydrolysis and purification of succinic anhydride to prepare succinic acid: Succinic anhydride was added to hot water at 85 °C for hydrolysis reaction. The reaction solution was concentrated by evaporation, crystallized, and recrystallized to obtain succinic acid with a purity greater than 99.5 wt%.

[0084] 3) Esterification of succinic acid to prepare BS: The monomers succinic acid and BDO were mixed into a pulp at a molar ratio of 1.00:1.50, and PTSA, an esterification catalyst accounting for 2.0 wt% of the total weight of succinic acid and BDO, was added. The esterification reaction was carried out under atmospheric pressure with distillation for 60 min at a temperature of 160 °C, and then the esterification reaction was carried out under reduced pressure with distillation for 45 min at a temperature of 180 °C and a pressure of 90 kPa to obtain the precursor BS.

[0085] 4) Polycondensation of BS to prepare PBS: The same as Comparative Example 1. The gaseous materials in the polycondensation reaction were collected. After distilling off water and tetrahydrofuran, the recovered BDO was recycled for use in step 3) of the esterification of succinic acid to prepare BS. The polycondensation reaction conditions, results, and polyester parameters are shown in Tables 3 and 4.

[0086] Comparative Example 3

[0087] Preparation of monomer DMS by hydrogenation / esterification of maleic anhydride and its transesterification and polycondensation with BDO to prepare PBS

[0088] 1) Hydrogenation and purification of maleic anhydride to prepare succinic anhydride: The same as Comparative Example 1.

[0089] 2) Methyl esterification and purification of succinic anhydride to prepare dimethyl succinate (DMS): Mix succinic anhydride and methanol in a molar ratio of 1.00:2.25, feed them into a reaction kettle, and carry out a ring-opening esterification reaction at 80 °C under atmospheric pressure to prepare monomethyl succinate (MMS). Then, feed it into a reaction kettle filled with macroporous strongly acidic cation exchange resin Amberlyst-15 (A-15), and carry out a second esterification reaction at 85 °C under atmospheric pressure. The reaction product is separated by vacuum distillation to obtain monomer DMS with a purity greater than 99.5 wt%.

[0090] 3) Transesterification of DMS to prepare BS: Mix monomer DMS and BDO in a molar ratio of 1.00:1.50, and add 0.10 wt% of the transesterification catalyst TBT based on the total weight of DMS and BDO. Carry out a transesterification reaction distillation at 160 °C under atmospheric pressure for 60 min, and then carry out a vacuum transesterification reaction distillation at 180 °C and a pressure of 90 kPa for 45 min to obtain the precursor BS.

[0091] 4) Polycondensation of BS to prepare PBS: Feed the precursor BS into a polycondensation reaction kettle, carry out a negative pressure polycondensation reaction at 210 °C and a pressure of 30 kPa for 60 min, and then carry out a vacuum polycondensation at 240 °C and a pressure of 50 Pa for 150 min to obtain PBS. Collect the gaseous materials in the polycondensation reaction, recover the BDO after removing water and tetrahydrofuran, and recycle it to step 3) for the transesterification of DMS to prepare BS. The polycondensation reaction conditions, results, and polyester parameters are shown in Tables 3 and 4.

[0092] Examples 9 - 24

[0093] Maleic anhydride esterification, hydrogenation to prepare GS and its co-polycondensation with a third monomer to synthesize PGSX

[0094] A1. Ring-opening esterification of maleic anhydride with polyols to prepare maleic acid polyol esters (GM):

[0095] According to the polyols, acid catalysts, reactor forms, and reaction process conditions shown in Table 5, mix maleic anhydride and polyol raw materials in an alcohol-to-anhydride molar ratio of 0.50 - 2.00:1.00, feed them into a reactor filled with an acid catalyst, and carry out a maleic anhydride ring-opening esterification reaction at a reaction temperature of 70 - 150 °C, a reaction pressure of 0.05 - 0.50 MPa, and a residence time of 0.50 - 3.00 h to prepare GM. Among them, the acid catalysts are PTSA, TfOH, TFSI, neodymium trifluoromethanesulfonate (TfONd), aluminum bis(trifluoromethanesulfonyl)imide (AlTFSI), Cs 2.5 H 0.5 PW 12 O 40 (CsHPA), HPA / SiO 2, CQA, HM, HZSM-5 or A-15. The reactor is selected from a continuous stirred tank reactor with an internal reflux fractionating column, a tubular reactor with a liquid acid catalyst, or a trickle bed adiabatic reactor with a solid acid particle catalyst. The reaction results corresponding to each example are listed in Table 5.

[0096] Table 5 Reaction process conditions and results for the preparation of maleic acid polyol esters (GM) by ring-opening esterification in Examples 9-24

[0097]

[0098] A2. Selective hydrogenation of maleic acid polyol esters (GM) to prepare succinic acid polyol esters (GS):

[0099] The GM obtained from the stirred tank reactor, tubular reactor with a liquid acid catalyst, or trickle bed reactor with a solid acid particle catalyst in step A1 is directly fed into a reactor filled with a hydrogenation catalyst. For the GM material obtained from the stirred tank reactor with a solid acid catalyst, the catalyst is first recovered by a filter, and then the liquid material is fed into the hydrogenation reactor. The hydrogenation reaction is carried out at a feed temperature of 60-120 °C, a hydrogen pressure of 1.00-2.50 MPa, a hydrogen to ester molar ratio of 8-30, and a residence time of 1.50-2.50 h to carry out the double bond hydrogenation of GM to prepare GS. Among them, the hydrogenation catalyst is 0.3 wt% Pd / γ-Al 2 O 3 、0.2 wt% Pd-1.0 wt% Ru / γ-Al 2 O 3 、0.1 wt% Pd-5.0 wt% Ni / γ-Al 2 O 3 or 5.0 wt% Ni-7.5 wt% Cu / γ-Al 2 O 3 , and the reactor is a slurry bed (the catalyst addition amount is 2.0 wt% of the GM feed amount) or a trickle bed adiabatic reactor. The hydrogenation reaction material is subjected to gas-liquid separation, and hydrogen is recycled. The liquid material using a trickle bed reactor is directly used as a polyester precursor, while the liquid of the material using a slurry bed reactor after filtering to recover the catalyst is used as a polyester precursor. The hydrogenation catalyst, reactor type, reaction process conditions and reaction results corresponding to each example are listed in Table 6.

[0100] Table 6 Reaction process conditions and results for the hydrogenation of GM to GS in Examples 9-24

[0101]

[0102] A3. Copolycondensation of succinic acid polyol esters (GS) with a third monomer to prepare PGSX:

[0103] Add a polymerization catalyst and a third monomer to the GS material in step A2, stir evenly and then feed it into an oligomerization reactor for a condensation polymerization reaction under reduced pressure to prepare an oligomer; then feed the oligomer into a prepolymerization reactor for a negative pressure polymerization reaction to prepare a prepolymer; finally, feed the prepolymer into a final polymerization reactor for a vacuum final condensation polymerization reaction to obtain PGSX. Among them, the polymerization catalyst is TBT, and the dosage is 0.03-0.08% of the weight of the GS material; the third monomer is adipic acid, 2,5-furandicarboxylic acid (FDCA), dimethyl terephthalate (DMT), methyl succinic anhydride (MSA), BDO, triethylene glycol, pentaerythritol, CHDM, ethylene oxide, glycolic acid, methyl lactate, glycolide, γ-butyrolactone or ε-caprolactone, and the addition amount of the third monomer is 0.05-0.50 of the molar amount of GS;

[0104] The oligomerization reaction temperature is 170-190 °C, the pressure is 50-90 kPa, and the residence time of the material is 30-45 min; the pre-condensation polymerization reaction temperature is 200-220 °C, the pressure is 10-30 kPa, and the residence time of the material is 20-45 min; the final condensation polymerization reaction temperature is 220-260 °C, the pressure is 30-75 Pa, and the residence time of the material is 90-120 min. Collect the gaseous phase materials of the condensation polymerization reaction (oligomerization, prepolymerization and final polymerization), distill off low-boiling substances such as water, and recycle the recovered polyol to step A1 for the ring-opening esterification of maleic anhydride to prepare GM. The polymerization catalyst dosage, reaction process conditions, reaction results and polyester parameters corresponding to each example are listed in Tables 7 and 8.

[0105] Table 7 Reaction process conditions for the condensation polymerization of succinic acid polyol ester to synthesize PGSX in Examples 9-24

[0106]

[0107] Table 8 Polymerization catalyst dosage, third monomer and its molar ratio to maleic anhydride (MA), polyester yield and its corresponding parameters for synthesizing PGSX

[0108]

[0109]

[0110] Comparative Example 4

[0111] Hydrogenation of maleic anhydride to prepare monomer succinic anhydride and its co-condensation with BDO and adipic acid to prepare PBSA

[0112] 1) Hydrogenation and refining of maleic anhydride to prepare succinic anhydride: the same as Comparative Example 1.

[0113] 2) Preparation of succinic acid - adipic acid - butanediol ester by co - esterification of succinic anhydride with BDO and adipic acid: Succinic anhydride, adipic acid and BDO were mixed into a pulp according to a molar ratio of 1.00:0.20:1.50, and PTSA, an esterification catalyst accounting for 1.2 wt% of the total feed weight, was added. The esterification reaction was carried out under atmospheric pressure at 160 °C for 45 min by distillation, and then the esterification reaction was carried out under reduced pressure at 180 °C and 90 kPa for 45 min by distillation to obtain the precursor succinic acid - adipic acid - butanediol ester.

[0114] 3) Preparation of PBSA by polycondensation of succinic acid - adipic acid - butanediol ester: To the precursor succinic acid - adipic acid - butanediol ester, TBT, a polymerization catalyst accounting for 0.08 wt% of the feed weight, was added. The polycondensation reaction was carried out under negative pressure at 210 °C and 30 kPa for 60 min, and then under vacuum at 240 °C and 50 Pa for 150 min to obtain poly (succinic acid - adipic acid - butanediol ester) (PBSA). The gaseous materials in the polycondensation reaction were collected. After distilling off water and tetrahydrofuran, the recovered BDO was recycled for use in step 2) of the preparation of succinic acid - adipic acid - butanediol ester by ring - opening esterification of succinic anhydride. The polycondensation reaction conditions, results and polyester parameters are shown in Tables 7 and 8.

[0115] Comparative Example 5

[0116] Preparation of monomer DMS by esterification / hydrogenation of maleic anhydride and its copolycondensation with BDO and PTA to prepare PBST

[0117] 1) Methyl esterification and purification of maleic anhydride to prepare dimethyl maleate (DMM): Maleic anhydride and methanol were mixed according to a molar ratio of 1.00:2.25 and fed into a reaction kettle. The ring - opening esterification reaction was carried out at 80 °C under atmospheric pressure to prepare monomethyl maleate (MMM). Then it was fed into a reaction kettle filled with macroporous strongly acidic cation exchange resin A - 15, and the diesterification reaction was carried out at 85 °C under atmospheric pressure. The reaction product was separated by negative - pressure rectification to obtain DMM with a purity greater than 99.5 wt%.

[0118] 2) Hydrogenation and purification of DMM to prepare dimethyl succinate (DMS): DMM was fed into a trickle - bed hydrogenation reactor filled with 0.5 wt% Pd / Al 2 O 3 catalyst. The hydrogenation reaction was carried out at a reaction temperature of 60 °C, a hydrogen pressure of 1.0 MPa, a hydrogen - anhydride molar ratio of 20, and a DMM weight hourly space velocity of 0.5 h -1 . The reaction materials were separated by gas - liquid separation, and hydrogen was recycled. The liquid product was separated by distillation to obtain monomer DMS with a purity greater than 99.5 wt%.

[0119] 3) Transesterification of DMS with BDO to prepare BS: The same as Comparative Example 3.

[0120] 4) Preparation of butylene terephthalate by esterification of terephthalic acid (PTA) and BDO: Mix PTA and BDO at a molar ratio of 1.00:1.50, and add PTSA, an esterification catalyst accounting for 1.50 wt% of the total weight of PTA and BDO. Conduct transesterification reaction distillation at normal pressure for 60 min at a temperature of 160 °C, and then conduct transesterification reaction distillation under reduced pressure for 45 min at a temperature of 180 °C and a pressure of 90 kPa to obtain the precursor butylene terephthalate.

[0121] 5) Copolycondensation of BS and butylene terephthalate to prepare PBST: Mix the precursor BS and butylene terephthalate at a molar ratio of 0.70:0.30, and feed them into a polycondensation reactor for negative pressure polycondensation reaction for 60 min at a temperature of 210 °C and a pressure of 30 kPa, and then conduct vacuum polycondensation for 150 min at a temperature of 240 °C and a pressure of 50 Pa to obtain poly(butylene succinate-co-terephthalate) (PBST). Collect the gaseous materials in the polycondensation reaction. After distilling off water and tetrahydrofuran, the recovered BDO is recycled for use in step 3) DMS transesterification to prepare BS. The polycondensation reaction conditions, results, and polyester parameters are shown in Tables 7 and 8.

[0122] Comparative Example 6

[0123] Preparation of monomer succinic acid by esterification / hydrogenation / hydrolysis of maleic anhydride and copolycondensation with BDO and TMP to prepare MPBS

[0124] 1) Methyl esterification and purification of maleic anhydride to prepare DMM: The same as Comparative Example 5.

[0125] 2) Hydrogenation and purification of DMM to prepare DMS: The same as Comparative Example 5.

[0126] 3) Hydrolysis and purification of DMS to prepare succinic acid: Feed DMS into a reactive distillation kettle filled with A-15 catalyst for hydrolysis reaction at 80 °C. The reaction solution is concentrated by evaporation, crystallized, and recrystallized to obtain monomer succinic acid with a purity greater than 99.5 wt%.

[0127] 4) Co-esterification of succinic acid with BDO and TMP to prepare butylene glycol-trimethylolpropane succinate: Mix succinic acid, BDO, and TMP at a molar ratio of 1.00:1.20:0.05, and add PTSA, an esterification catalyst accounting for 2.00 wt% of the feed weight. Conduct transesterification reaction distillation at normal pressure for 60 min at a temperature of 160 °C, and then conduct transesterification reaction distillation under reduced pressure for 45 min at a temperature of 180 °C and a pressure of 90 kPa to obtain the precursor butylene glycol-trimethylolpropane succinate.

[0128] 5) Preparation of MPBS by polycondensation of butanediol - trimethylolpropane succinate: Add 0.08 wt% of the polymerization catalyst TBT based on the weight of the feed to the precursor butanediol - trimethylolpropane succinate and feed it into the polycondensation reactor. Carry out negative pressure polycondensation reaction at a temperature of 210 °C and a pressure of 30 kPa for 45 min, and then carry out vacuum polycondensation at a temperature of 240 °C and a pressure of 50 Pa for 120 min to obtain trimethylolpropane - modified poly(butylene succinate) (MPBS). Collect the gaseous materials of the polycondensation reaction. After distilling off water and tetrahydrofuran, the recovered BDO is recycled for use in step 4) the esterification of succinic acid to prepare butanediol - trimethylolpropane succinate. The polycondensation reaction conditions, results and polyester parameters are shown in Tables 7 and 8.

[0129] Examples 25 - 30

[0130] Synthesis of block copolymer PGS - co - PQD1 by co - polycondensation of maleic anhydride esterification, hydrogenation to prepare succinic acid polyol ester and its prepolymer and polymer PQD

[0131] A1. Ring - opening esterification of maleic anhydride with polyol to prepare maleic acid polyol ester (GM):

[0132] According to the polyol, acid catalyst and reaction conditions shown in Table 9, mix maleic anhydride with ethylene glycol, BDO or HDO at an alcohol - anhydride molar ratio of 1.25:1.00 respectively, and feed it into the reactor filled with the acid catalyst. Carry out the ring - opening esterification reaction of maleic anhydride at a reaction temperature of 120 °C, a reaction pressure of 0.09 MPa and a residence time of 0.75 h to prepare GM. Among them, the acid catalyst is selected from PTSA or TfOH, and the reactor is a continuous stirred - tank reactor with an internal reflux fractionating column. The reaction results corresponding to each example are listed in Table 9.

[0133] Table 9 Reaction process conditions and results of ring - opening esterification of maleic anhydride with polyol to prepare GM in Examples 25 - 30

[0134]

[0135] A2. Selective hydrogenation of maleic acid polyol ester (GM) to prepare succinic acid polyol ester (GS):

[0136] Feed the GM material prepared in step A1 into the reactor filled with the hydrogenation catalyst. Carry out the double - bond hydrogenation of GM at a feed temperature of 85 °C, a hydrogen pressure of 1.50 MPa, a hydrogen - ester molar ratio of 10 and a residence time of 1.00 h to prepare GS. Among them, the hydrogenation catalyst is 0.3 wt% Pd / Al 2 O 3 catalyst, and the reactor is a trickle - bed adiabatic reactor. The reactor forms and results corresponding to each example are listed in Table 10.

[0137] Table 10 Reaction Process Conditions and Results of GM Hydrogenation to GS in Examples 25 - 30

[0138]

[0139] A3. Preparation of block copolymer by co - polycondensation of succinic acid polyol ester (GS) prepolymer and PQD: Add polymerization catalyst TBT accounting for 0.03 - 0.08% of the feed weight to the GS material in step A2, stir evenly and then send it into the oligomerization reactor for reduced - pressure polycondensation reaction to prepare oligomers; then send the oligomers into the prepolymerization reactor for negative - pressure polycondensation reaction to prepare prepolymers; finally, mix the prepolymers with polymer PQD and send them into the final - polymerization reactor for vacuum final - polycondensation reaction to prepare block copolymer PGS - co - PQD. Among them, polymer PQD is PEG - 400, PPG - 600, PTMG - 800, PET - 1000, PVA - 400 or PPC - 600. The oligomerization reaction temperature is 170 °C, pressure is 70 kPa and the material residence time is 45 min; the pre - polycondensation reaction temperature is 200 °C, pressure is 10 kPa and the material residence time is 30 min; the final - polycondensation reaction temperature is 240 °C, pressure is 50 Pa and the material residence time is 120 min. Collect the gaseous materials of the polycondensation reaction (oligomerization, prepolymerization and final - polymerization), distill and remove low - boiling substances such as water, and recycle the recovered polyol to step A1 for maleic anhydride ring - opening esterification to prepare GM. The reaction results and polyester parameters corresponding to each example are listed in Tables 11 and 12.

[0140] Table 11 Reaction Process Conditions for GS Polycondensation to Synthesize PGS - co - PQD

[0141]

[0142] Table 12 Polymerization Catalyst Dosage, Weight Ratio of PQD to PGS, Polyester Yield and Their Corresponding Parameters for Synthesizing PGS - co - PQD

[0143]

[0144] As can be seen from the content shown in Tables 1-12 above, in Examples 1-30, for the ring-opening esterification reaction of maleic anhydride and polyol in Step A1, at an alcohol-to-anhydride molar ratio of 0.5-2.0, a temperature of 70-150 °C, a pressure of 0.05-0.50 MPa, and a material residence time of 0.5-3.0 h, whether using an organic liquid strong acid catalyst (such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, bis(trifluoromethanesulfonyl)imide, trifluoromethanesulfonate, or bis(trifluoromethanesulfonyl)imide salt) and a batch (intermittent or continuous) or tubular reaction process, or using a solid strong acid catalyst (such as heteropolyacid and its salts, hydrogen-type molecular sieve, solid superacid, or hydrogen-type macroporous cation exchange resin, etc.) and a batch (intermittent or continuous) or fixed-bed reaction process, maleic anhydride can be efficiently converted into maleate, and the conversion rate of maleic anhydride and the selectivity of maleic polyol ester are both about 100%.

[0145] In the hydrogenation reaction of maleic polyol in Step A2, at a hydrogen-to-ester molar ratio of 8-30, a temperature of 60-120 °C, a hydrogen pressure of 0.75-2.50 MPa, and a material residence time of 0.5-2.5 h, using a single-metal or double-metal supported hydrogenation catalyst, whether adopting a powder catalyst and a slurry bed reaction process or a pellet catalyst and a trickle bed reaction process, the double bond of maleic polyol can be efficiently hydrogenated and saturated, the conversion rate of maleic polyol ester is 100%, and the selectivity of succinic polyol ester is greater than 99.2%.

[0146] In the polycondensation reaction stage of Step A3, when the dosage of tetrabutyl titanate as the polymerization catalyst is 0.03-0.08% of the total feed weight of the polymerization reaction, with or without the addition of a third monomer or other polymers, succinic polyol ester is subjected to three polycondensation or co-polycondensation steps of oligomerization (temperature 160-190 °C, pressure 50-90 kPa, and residence time 30-60 min), prepolymerization (temperature 190-220 °C, pressure 5-30 kPa, and residence time 20-45 min), and final polymerization (temperature 210-260 °C, pressure 30-90 Pa, and residence time 90-150 min). The prepared polybutylene succinate PGS, copolyester PGSX, or block copolymer PBS-co-PQD all have high yields and good properties: the feed yield is 69.07-90.28 wt%, and the effective yield is 87.60-93.56 wt%; the weight-average molecular weight Mw is 132,000-278,000, the melt index is 6.8-18.2 g / 10 min, and the acid value is 12-28 mol / t.

[0147] Compared with Comparative Examples 1-6, the preparation method of the present invention only needs to go through three stages: maleic anhydride ring-opening esterification, double-bond hydrogenation, and condensation polymerization, and polyester products can be obtained without separation and purification during the process. Comparative Examples 1 and 4 need to go through 4 steps: maleic anhydride hydrogenation, succinic anhydride purification, succinic anhydride ring-opening esterification, and polycondensation. Comparative Example 2 needs to go through 6 steps: maleic anhydride hydrogenation, succinic anhydride purification, succinic anhydride hydrolysis, succinic acid purification, succinic acid esterification, and polycondensation. Comparative Example 3 needs to go through 7 steps: maleic anhydride hydrogenation, succinic anhydride purification, monomethyl esterification and dimethyl esterification of succinic anhydride, DMS purification, DMS transesterification, and polycondensation. Comparative Example 5 needs to go through 7 steps: monomethyl esterification and dimethyl esterification of maleic anhydride, DMM purification, DMM hydrogenation, DMS purification, DMS transesterification, and polycondensation. Comparative Example 6 needs to go through 9 steps: monomethyl esterification and dimethyl esterification of maleic anhydride, purification of dimethyl maleate (DMM), DMM hydrogenation, purification of dimethyl succinate (DMS), DMS hydrolysis, succinic acid purification, succinic acid esterification, and polycondensation to synthesize polyester products.

[0148] Moreover, under the same conditions, the polyester yield of the examples is significantly higher than that of the comparative examples. For example, when the raw material feeding ratio is the same: the feeding yield of polyester PBS in Example 8 is 79.26 wt% and the effective yield is 89.83 wt%, higher than the feeding yield of polyester PBS in Comparative Example 1, which is 77.78 wt% and the effective yield is 85.82 wt%. The feeding yield of polyester PBS in Example 2 is 73.20 wt% and the effective yield is 90.02 wt%, higher than the feeding yield of polyester PBS in Comparative Example 2, which is 70.63 wt% and the effective yield is 83.28 wt%, and the feeding yield of polyester PBS in Comparative Example 3, which is 71.28 wt% and the effective yield is 84.58 wt%. The feeding yield of copolyester PBSA in Example 10 is 80.24 wt% and the effective yield is 88.12 wt%, higher than the feeding yield of polyester PBSA in Comparative Example 4, which is 79.00 wt% and the effective yield is 84.80 wt%, and the feeding yield of polyester PBST in Comparative Example 5, which is 71.82 wt% and the effective yield is 83.02 wt%. The feeding yield of copolyester MBS in Example 16 is 80.10 wt% and the effective yield is 90.12 wt%, higher than the feeding yield of polyester MPBS in Comparative Example 6, which is 76.33 wt% and the effective yield is 82.76 wt%.

[0149] By comparing Comparative Examples 1 and 4 with Comparative Examples 2, 6, 3, and 5, it can also be found that the acid anhydride ring-opening esterification method has a higher yield of synthesizing polyester than the direct esterification method of diacid and the dimethyl ester transesterification method.

[0150] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for producing a succinic acid polyol ester and a polycondensate thereof, characterized in that: The steps include: A1, the raw materials maleic anhydride and polyol are mixed in a molar ratio of 1.00: (0.50-2.50), and then sent into an esterification reactor filled with an acid catalyst, and maleic anhydride ring-opening esterification reaction is carried out at a reaction temperature of 40-180° C., a reaction pressure of 0.01-1.00 MPa, and a residence time of 0.10-5.00 h to prepare maleic acid polyol ester; A2, directly feeding the maleic acid polyol ester material obtained in step A1 into a hydrogenation reactor filled with a hydrogenation catalyst, and hydrogenating the double bonds of the maleic acid polyol ester to prepare succinic acid polyol ester at a feed temperature of 40-180° C., a hydrogen pressure of 0.20-5.00 MPa, a hydrogen-ester molar ratio of 2-50, and a residence time of 0.25-5.00 h; A3, polycondensing the succinic acid polyol ester material obtained in step A2 in the presence of a polymerization catalyst to prepare polysuccinic acid polyol ester PGS, or co-condensing it with a third monomer to prepare succinic acid polyol-third monomer copolyester PGSX, or block copolymerizing the prepolymer of succinic acid polyol ester with other polymers PQD to prepare a block copolymer of polysuccinic acid polyol ester PGS-co-PQD; Wherein, the polyol is selected from at least one of aliphatic, aromatic or heterocyclic dihydric or higher alcohols, the third monomer is selected from one or more of polyacids, polyacid anhydrides, polyacid esters, polyols, polyol ethers, hydroxy acids, hydroxy acid esters, lactides or lactones, and the polymer PQD is selected from one or more of polyethers, polyesters, polyvinyl alcohols or polycarbonates; the acid catalyst is selected from a liquid acid catalyst and / or a solid acid catalyst, and the hydrogenation catalyst is selected from at least one of catalysts of transition metals and / or precious metals loaded on porous carrier materials.

2. The method for producing a succinic acid polyol ester and a polycondensate thereof according to claim 1, characterized in that: In step A1, the esterification reactor is a tower reactor, a pipeline reactor or a fixed bed reactor, and the reaction mode is intermittent or continuous reaction; The esterification reaction process conditions are: maleic anhydride to polyol molar ratio of 1.00: (0.75-2.00), reaction temperature of 55-150° C., reaction pressure of 0.05-0.50 MPa, and residence time of 0.25-3.00 h; Preferably, the esterification reaction process conditions are: maleic anhydride to polyol molar ratio 1.00: (1.00-1.75), reaction temperature 70-130° C., reaction pressure 0.09-0.25 MPa, residence time 0.50-2.00 h; More preferably, the esterification reaction process conditions are: maleic anhydride to polyol molar ratio of 1.00: (1.05-1.50), reaction temperature of 80-120° C., reaction pressure of 0.10-0.20 MPa, and residence time of 0.75-1.50 h.

3. The method for producing a succinic acid polyol ester and a polycondensate thereof according to claim 1, characterized in that: In step A2, the hydrogenation reactor is a tank reactor or a fixed bed reactor, and the reaction mode is intermittent or continuous reaction; The process conditions for the double bond hydrogenation reaction of maleic acid polyol ester are: feed temperature 50-150° C., hydrogen pressure 0.50-3.00 MPa, hydrogen-ester molar ratio 5-40, and residence time 0.50-3.00 h; Preferably, the process conditions for the double bond hydrogenation reaction of maleic acid polyol ester are: feed temperature 60-120°C, hydrogen pressure 0.75-2.50MPa, hydrogen-ester molar ratio 8-30, residence time 0.75-2.5h; More preferably, the process conditions for the double bond hydrogenation reaction of maleic acid polyol ester are: feed temperature 70-100° C., hydrogen pressure 1.00-2.00 MPa, hydrogen-ester molar ratio 10-20, and residence time 1.00-2.00 h.

4. The method for producing a succinic acid polyol ester and a polycondensate thereof according to claim 1, characterized in that: In step A1, the liquid acid catalyst is selected from at least one of methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, fluorosulfonic acid, trifluoromethanesulfonic acid, bistrifluoromethanesulfonyl imide, trifluoromethanesulfonate or bistrifluoromethanesulfonyl imide salt, and the amount used is 0.02-2.00wt% of the total liquid feed; preferably, the liquid acid catalyst is selected from p-toluenesulfonic acid, trifluoromethanesulfonic acid, bistrifluoromethanesulfonyl imide, or trifluoromethanesulfonate or bistrifluoromethanesulfonyl imide salt of Al, Cu, Fe, Ti, Zr, La, Ce, Sm or Nd, and the amount used is 0.05-1.00wt% of the total liquid feed; The solid acid catalyst is selected from at least one of acidic oxides, heteropolyacids and salts thereof, solid superacids, hydrogen molecular sieves or hydrogen cation exchange resins, and the amount used in a reactor is 1.0 to 10.0 wt% of the total liquid feed; preferably γ-Al2O3, SiO2-Al2O3, Nb2O5, H3PMo 12 O 40 、H3PW 12 O 40 , Cs 2.5 H 0.5 PW 12 O 40 、WO3 / ZrO2、MoO3 / TiO2、SO4 2- / TiO2-La2O3, SO4 2- / At least one of ZrO2, HM, Hβ, HZSM-5, HZSM-11, HMCM-22, HMCM-49, Amberlyst-15, Amberlyst-35, D-72 or Nafion, and the amount used in a tower reactor is 2.0 to 7.5 wt% of the total liquid feed.

5. The method for producing a succinic acid polyol ester and a polycondensate thereof according to claim 1, characterized in that: In step A2, the hydrogenation catalyst is selected from at least one of activated carbon, SiO2, γ-Al2O3, θ-Al2O3, SiO2-Al2O3, TiO2, ZrO2, HM, HHEU, Hβ, HZSM-5, HZSM-22, HMCM-22, HMCM-41, HMCM-48, HMCM-49, HMCM-56, SBA-15, ZEO-1 or KIT-6, which is a single metal or bimetallic catalyst loaded with Ni, Cu, Ru, Pd or Pt. In the hydrogenation catalyst, the active component is 2 to 30% of Ni or Cu, or 0.5 to 10.0 wt% of Ru, or 0.05 to 5.0 wt% of Pd or Pt; Preferably, the hydrogenation catalyst is an activated carbon, SiO2, γ-Al2O3, HM, HZSM-5, HMCM-22, HMCM-41 or SBA-15 loaded Ni, Pd, Pt, Ni-Cu, Pd-Ni or Pd-Ru catalyst, wherein the active component is a Ni or Cu loading amount of 5 to 10%, or a Ru loading amount of 2.0 to 5.0 wt%, or a Pd or Pt loading amount of 0.2 to 1.0 wt%.

6. The method for producing a succinic acid polyol ester and a polycondensate thereof according to claim 1, characterized in that: The process of step A3 includes the following process: adding a polymerization catalyst or a polymerization catalyst and a third monomer to the succinic acid polyol ester material prepared in step A2, stirring evenly, and then feeding it into a polymerization reactor to carry out a reduced pressure polymerization reaction to prepare a polymer; then feeding the polymer into a prepolymerization reactor to carry out a negative pressure precondensation reaction to prepare a prepolymer; finally, feeding the prepolymer into a final polymerization reactor or mixing the prepolymer with other polymers PQD evenly and then feeding it into a final polymerization reactor to carry out a vacuum final condensation reaction to prepare PGS or PGSX or PGS-co-PQD; wherein, The polymerization catalyst is a compound containing titanium, antimony or germanium, preferably at least one of titanium chloride, butoxytitanium chloride, tetraalkyl titanate, tetrahydroxyalkyl titanate or dialkyl titanate, more preferably at least one of tetrabutyl titanate, tetrahydroxybutyl titanate, diethylene glycol titanate and dibutylene glycol titanate; The amount of the polymerization catalyst is 0.01 to 0.25 wt% of the succinic acid polyol ester material; preferably 0.02 to 0.15 wt%; more preferably 0.03 to 0.08 wt%; The polymerization reaction operating conditions are: temperature 150-200°C, pressure 50-100 kPa and material residence time 20-60 min, preferably temperature 160-180°C, pressure 70-90 kPa and material residence time 30-45 min; The pre-polycondensation reaction operating conditions are: temperature 180-230°C, pressure 1-50kPa and material residence time 20-60min, preferably temperature 190-210°C, pressure 5-30kPa and material residence time 30-45min; The final polycondensation reaction operating conditions are: temperature 200-260° C., pressure 10-200 Pa and material residence time 60-180 min, preferably temperature 220-240° C., pressure 50-90 Pa and material residence time 90-150 min.

7. The method for producing a succinic acid polyol ester and a polycondensate thereof according to claim 6, characterized in that: When the target product is succinic acid polyol-third monomer copolyester PGSX, a third monomer is added in step A3, and the molar ratio of the third monomer to maleic anhydride is 0.05-1.00; or, When the target product is a block copolymer of polysuccinic acid polyol ester PGS-co-PQD, a polymer PQD is added in step A3, and the weight ratio of the polymer PQD to the prepolymer is (10-30):(70-90).

8. The method for producing a succinic acid polyol ester and a polycondensate thereof according to claim 1, characterized in that: The polyol is selected from C2 to C 22 Fatty polyols, C8~C 16 Aromatic polyols or C4~C 10 One or more of the heterocyclic polyols; preferably one or more of 1,2-ethanediol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, dipropylene glycol, butene glycol, butynediol, 2-methyl-1,3-propanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, pentaerythritol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, o-phthalic acid, isophthalic acid, p-phthalic acid, 2,5-furan dimethanol, 2,6-pyran dimethanol or 2,5-thiophenedimethanol.

9. The method for producing a succinic acid polyol ester and a polycondensate thereof according to claim 1, characterized in that: The third monomer is selected from C2 to C 22 Fatty polyacid, C8~C 16 Aromatic polyacid or C4~C 10 Heterocyclic polyacids, or cyclic anhydrides or esters of these polyacids; C2~C 22 Fatty polyols, C8~C 16 Aromatic polyols or C4~C 10 Heterocyclic polyols, or cyclic ethers of these polyols; C2~C 10 Hydroxy fatty acids or their esters, lactides or lactones; Preferably, the third monomer is selected from methylsuccinic acid, 1,5-pentanedioic acid, 1,6-hexanediol, 1,10-decanedioic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, 1,4-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,5-furan dicarboxylic acid or its methyl ester, methylsuccinic anhydride, glutaric anhydride, methylglutaric anhydride, phthalic anhydride, trimellitic anhydride or pyromellitic anhydride; ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, butene glycol, butynediol, 2- 1,3-Methylpropanediol, neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol, erythritol, sorbitol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, terephthalylidene alcohol or 2,5-furandimethanol, ethylene oxide, propylene oxide, epichlorohydrin, tetrahydrofuran, furan, tetrahydrofurfuryl alcohol, furfuryl alcohol, pyran or tetrahydropyran; glycolic acid, lactic acid, 3-hydroxypropionic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid or their methyl esters, glycolide, lactide, β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone or ε-caprolactone; More preferably, the third monomer is selected from 1,5-pentanedioic acid, 1,6-hexanediol, 1,10-decanedioic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, 2,5-furan dicarboxylic acid or its dimethyl ester, methylsuccinic anhydride, glutaric anhydride, methylglutaric anhydride; ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, butylene glycol, butynediol, neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, 1,4-cyclohexanedimethanol, terephthalic acid or 2,5-furan dimethanol, ethylene oxide, propylene oxide; glycolic acid, lactic acid, 3-hydroxypropionic acid, 4-hydroxybutyric acid or their methyl esters, glycolide, lactide, γ-butyrolactone, δ-valerolactone or ε-caprolactone.

10. The method for producing a succinic acid polyol ester and a polycondensate thereof according to claim 1, characterized in that: The polymer PQD is selected from one of polyether, polyester, polyvinyl alcohol or polycarbonate with a molecular weight of 150 to 2000; Preferably, the polymer PQD is selected from polyethylene glycol, polypropylene glycol or polybutylene glycol with a molecular weight of 200 to 800, polyethylene succinate glycol, polypropylene succinate glycol, polybutylene succinate glycol, polybutylene adipate glycol, polyethylene terephthalate glycol or polybutylene terephthalate glycol with a molecular weight of 300 to 1000, polyglycolic acid, polylactic acid, polyhydroxy fatty acid, polybutyrolactone or polycaprolactone with a molecular weight of 200 to 1000, polyvinyl alcohol with a molecular weight of 150 to 800, polyethylene carbonate and polypropylene carbonate with a molecular weight of 200 to 1000; More preferably, the polymer PQD is selected from PEG, PPG or PTMG with a molecular weight of 200 to 400, polyethylene succinate diol, polypropylene succinate diol, polybutylene succinate diol, polybutylene adipate diol, polyethylene terephthalate diol or polybutylene terephthalate diol with a molecular weight of 300 to 600, polyglycolic acid, polylactic acid, polyhydroxy fatty acid, polybutyrolactone or polycaprolactone with a molecular weight of 300 to 600, polyvinyl alcohol with a molecular weight of 200 to 400, and polyethylene carbonate or polypropylene carbonate with a molecular weight of 300 to 600.

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