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CN-121975103-A - CO (carbon monoxide)2Process for preparing base polycarbonate polyols

CN121975103ACN 121975103 ACN121975103 ACN 121975103ACN-121975103-A

Abstract

The invention discloses a preparation method of CO 2 -based polycarbonate polyol, and belongs to the technical field of preparation of CO 2 -based polyol. According to the method, CO 2 and propylene oxide are used as main raw materials, and a synergistic catalytic system consisting of specific alkali and annular Si-O-Si skeleton multicenter borane is adopted under the participation of an initiator, so that the efficient synthesis of the target CO 2 -based polycarbonate polyol is realized. The catalyst system effectively solves the problems that the traditional organoborane catalyst is easy to be passivated by protons in the initiator and the generation amount of the byproduct cyclic carbonate is large, and remarkably improves the catalytic efficiency and the proton tolerance of the catalyst. The precise regulation and control of the composition and the molecular weight of the polycarbonate are realized by regulating and controlling the reaction conditions, so that the CO 2 base polycarbonate polyol with different structures and performances can be controllably prepared, and the diversified application requirements are met.

Inventors

  • LI ZHIBO
  • LIU SHAOFENG
  • WANG ZEHAO
  • LIU MINGHAO
  • ZHANG JINBO

Assignees

  • 青岛科技大学

Dates

Publication Date
20260505
Application Date
20260119

Claims (10)

  1. 1. A preparation method of CO 2 -based polycarbonate polyol is characterized in that propylene oxide and CO 2 are subjected to ring-opening copolymerization reaction under the action of an organic synergistic catalytic system in the presence of an initiator, wherein the organic synergistic catalytic system consists of alkali or onium salt and a cyclic Si-O-Si skeleton multicenter borane catalyst.
  2. 2. The method for preparing a CO 2 based polycarbonate polyol according to claim 1, wherein the initiator is selected from polyols R- (OH) n , R is C 2 ～C 12 linear or branched alkyl, cycloalkyl, aryl, polyether chain or polyol skeleton, and n is a positive integer of 2 to 4.
  3. 3. The method for producing a CO 2 -based polycarbonate polyol according to claim 2, wherein the base is one or more selected from the group consisting of alkoxide, organic amine, and phosphazene base, and the onium salt is one or more selected from the group consisting of bis [ triphenylphosphine ] imino salt, tetraphenylphosphonium salt, tetraalkylammonium salt, tris [ tris (dimethylamino) imino ] phosphonium salt, and tetrakis [ tris (dimethylamino) imino ] phosphonium salt.
  4. 4. The method for preparing a CO 2 based polycarbonate polyol according to claim 3, wherein the cyclic Si-O-Si skeleton multicenter borane catalyst is selected from one or more of the group consisting of cyclotron (V3B), cyclotetraborane (V4B) and cage octaboron (POSS-B8).
  5. 5. The method for producing a CO 2 -based polycarbonate polyol according to claim 4, wherein the molar ratio of the base or onium salt to the cyclic Si-O-Si skeleton multicenter borane catalyst is (0.5-2): 1.
  6. 6. The method for preparing a CO 2 -based polycarbonate polyol according to claim 5, wherein the polymerization reaction temperature is 25-120 ℃ and the CO 2 pressure is 0.5-5 MPa.
  7. 7. The method for producing a CO 2 -based polycarbonate polyol according to claim 5, wherein the molar ratio of the initiator to propylene oxide is 1 (10 to 1000).
  8. 8. The method for preparing a CO 2 -based polycarbonate polyol according to claim 5, wherein the content of carbonate units of the CO 2 -based polycarbonate polyol is 10-80 mol%, the number average molecular weight is 0.1-50 kg/mol, and the molecular weight distribution coefficient is less than 2.0.
  9. 9. The method for producing a CO 2 -based polycarbonate polyol according to any one of claims 6 to 8, wherein after the ring-opening copolymerization reaction, ethylene oxide is introduced into the reaction system to carry out the end-capping reaction, and a CO 2 -based polycarbonate polyol having a primary hydroxyl group as an end group is produced, wherein the molar ratio of the ethylene oxide to the initiator is (1 to 100): 1.
  10. 10. The method for producing a CO 2 -based polycarbonate polyol according to claim 2, wherein the initiator is selected from one or more of ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 8-octanediol, 1, 10-decanediol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1, 3-cyclopentanediol, 1, 2-cyclohexanediol, 1, 3-cyclohexanediol, 1, 4-cyclohexanediol, 1, 2-cyclohexanedimethanol, 1, 4-cyclohexanedimethanol, 2-methyl-1, 3-propanediol, neopentyl glycol, 2-ethylhexyl-1, 3-diol, trimethylolethane, trimethylolpropane, 1,2, 4-butanetriol, glycerol, pentaerythritol.

Description

Preparation method of CO 2 -based polycarbonate polyol Technical Field The invention relates to the technical field of preparation of CO 2 -based polyol, in particular to a preparation method of CO 2 -based polycarbonate polyol. Background The CO 2 -based polyol is a new polyol material with a low molecular weight and a hydroxyl-terminated functional structure and simultaneously contains a carbonate bond and an ether bond. The polyol has the potential of directly replacing the traditional petroleum-based polyether or polyester polyol, does not need to modify the existing production equipment or process flow, and has wide application prospect in the fields of polyurethane synthesis and the like. The backbone structure of conventional polyether polyols consists mainly of flexible ether linkages. The ether linkage, due to its lower rotational energy barrier, imparts higher flexibility and weaker intermolecular forces to the polymer segments, resulting in lower glass transition temperatures (T g) of the material. For example, the T g of poly 1, 2-propylene glycol (PPG) is about-70 ℃ to-50 ℃. In contrast, carbonate groups in CO 2 based polyols can significantly enhance the rigidity of the molecular chain and the interaction forces between the segments, increasing the energy barrier that needs to be overcome by the segment motions, and thus increasing T g (depending on the ratio of carbonate to ether segments). Therefore, the polyurethane material synthesized by taking the polyalcohol as a raw material generally has excellent mechanical strength, hydrolysis resistance and aging resistance, has performance advantages and cost performance, and is particularly suitable for application scenes with more comprehensive requirements on material performance. At present, CO 2 and epoxide are subjected to ring-opening copolymerization in the presence of a catalyst and an active hydrogen-containing initiator in the synthesis of CO 2 -based polyol, but the active hydrogen initiator is easy to react with the active center of the catalyst to cause the deactivation of the catalyst, so that the reaction efficiency is reduced, and meanwhile, cyclic carbonate byproducts which are difficult to separate are easy to generate, so that the purity and the yield of the product are influenced. Therefore, developing a high-efficiency catalytic system with excellent proton tolerance and high selectivity becomes a key technical challenge for improving the synthesis efficiency of the CO 2 -based polyol. Although the prior art reports that partial metal organic catalysts (such as zinc, cobalt and aluminum complexes) and single-component organic catalysts (such as quaternary ammonium salts and single-center Lewis bases) are used for PO/CO 2 copolymerization, the problems that the catalysts are easy to be passivated, the activity is rapidly attenuated under the condition of protonic starting agents such as alcohol, water and the like, the control of the reaction path is insufficient, the proportion of cyclic carbonate byproducts is high and the like exist generally. Disclosure of Invention Based on the prior study and the existing problems, the invention provides a preparation method of CO 2 -based polycarbonate polyol after further study and analysis, which takes CO 2 and propylene oxide as main raw materials, and adopts a synergistic catalytic system consisting of specific alkali and cyclic Si-O-Si skeleton multicenter borane to realize the efficient synthesis of target CO 2 -based polycarbonate polyol under the participation of an initiator. The catalyst system effectively solves the problems that the traditional organoborane catalyst is easy to be passivated by protons in the initiator and the generation amount of the byproduct cyclic carbonate is large, and remarkably improves the catalytic efficiency and the proton tolerance of the catalyst. In order to achieve the above purpose, the present invention provides the following technical solutions: In the presence of initiator, propylene oxide and CO 2 are subjected to ring-opening copolymerization under the action of organic synergistic catalytic system, and the organic synergistic catalytic system consists of alkali or onium salt and cyclic Si-O-Si skeleton multicenter borane catalyst. Preferably, the initiator is selected from the group consisting of polyols R- (OH) n, R is a C 2～C12 linear or branched alkyl, cycloalkyl, aryl, polyether chain or polyol backbone, and n is a positive integer from 2 to 4. Preferably, the base is selected from one or more of alkoxide, organic amine, phosphazene base, onium salt is selected from one or more of bis [ triphenylphosphine ] imino salt, tetraphenylphosphonium salt, tetraalkylammonium salt (tetramethylammonium salt, tetraethylammonium salt, tetrabutylammonium salt), tris [ tris (dimethylamino) imino ] phosphonium salt, and tetrakis [ tris (dimethylamino) imino ] phosphonium salt. The structural formulas are as follows: Wherein the alkoxide has the stru