CN-122011325-A - Polyurethane elastomer and preparation method and application thereof

Abstract

The invention relates to the field of high polymer materials, in particular to a polyurethane elastomer, a preparation method and application thereof, wherein the polyurethane elastomer is prepared from polyester-polyether-polyester triblock dihydric alcohol, aromatic isocyanate and micromolecular dihydric alcohol through a prepolymer method, and the molecular chain of the micromolecular dihydric alcohol comprises ether bonds. According to the polyurethane elastomer, the chain extender is replaced by the ether micromolecule dihydric alcohol and is matched with the rigid structure of the aromatic isocyanate, so that the polyurethane elastomer can keep better mechanical properties under the condition that a soft segment is not designed, the soft segment structure is further designed, the soft segment structure of the polyester-polyether-polyester triblock is introduced, so that the distribution of the soft segment and the hard segment in the isocyanate is more uniform, the mechanical properties of the prepared polyurethane elastomer are obviously improved, and the ionic conductivity is further improved due to the good ionic conductivity of the ester group, so that the common improvement of the ionic conductivity and the mechanical properties is realized.

Inventors

• MA JUN
• OUYANG JIE
• CHEN LINLIN

Assignees

• 广州冠志新材料科技有限公司

Dates

Publication Date

20260512

Application Date

20260209

Claims (9)

1. 1. A polyurethane elastomer is characterized in that the polyurethane elastomer is prepared from polyester-polyether-polyester triblock dihydric alcohol, aromatic isocyanate and micromolecular dihydric alcohol through a prepolymer method, wherein the molecular chain of the micromolecular dihydric alcohol comprises ether bonds.
2. 2. The polyurethane elastomer according to claim 1, wherein the polyurethane elastomer is prepared from, by weight, aromatic isocyanate, 100 parts of polyester-polyether-polyester triblock diol, 0.01-1 part of titanate catalyst and 5-20 parts of small molecular diol by a prepolymer method, and the molar ratio of NCO in the aromatic isocyanate to OH in the polyester-polyether-polyester triblock diol is (1-1.2): 1.
3. 3. The polyurethane elastomer of claim 1, wherein the aromatic isocyanate is diphenylmethane diisocyanate.
4. 4. The polyurethane elastomer of claim 1, wherein the small molecule diol has a functionality of 2.
5. 5. The polyurethane elastomer of claim 1, wherein the small molecule diol comprises one of diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol.
6. 6. The polyurethane elastomer according to claim 1, wherein the hydroxyl value of the polyester-polyether-polyester triblock diol is 28 to 112 mgKOH/g.
7. 7. The polyurethane elastomer according to claim 1, wherein the polyester-polyether-polyester triblock diol is obtained by ring-opening polymerization reaction of polyethylene glycol or polytetrahydrofuran serving as a macromolecular initiator and epsilon-caprolactone.
8. 8. A method for preparing a polyurethane elastomer according to any one of claims 1 to 7, which is characterized by comprising the steps of reacting the polyester-polyether-polyester triblock diol with an excessive amount of the aromatic isocyanate at 40 to 100 ℃ for 0.5 to 10 hours to generate a prepolymer with an isocyanate group at the end, adding the micromolecular diol into the prepolymer, and carrying out chain extension and curing at 60 to 120 ℃ for 2 to 16 hours to obtain the polyurethane elastomer.
9. 9. Use of a polyurethane elastomer according to any of claims 1 to 7 as polymer electrolyte for solid state lithium batteries.

Description

Polyurethane elastomer and preparation method and application thereof Technical Field The invention relates to the field of high polymer materials, in particular to a polyurethane elastomer and a preparation method and application thereof. Background The alkali metal secondary battery represented by lithium and sodium batteries has wide application, and commercial electrolyte is mainly liquid electrolyte with carbonic ester organic micromolecules as solvent. However, the electrolyte has the problems of easy leakage, easy combustion, narrow electrochemical stability window, easy side reaction, lithium dendrite generation and the like, brings serious potential safety hazard to the battery, and simultaneously limits the development of the battery with high energy density. In order to solve the problems of the traditional liquid electrolyte, researchers develop novel electrolytes, wherein the polymer electrolyte has the advantages of light weight, flexibility, good processability, easiness in large-area preparation, low cost, good interface compatibility and the like, and has great application potential. Among the polymer electrolytes, polyurethane (PU) polymer electrolytes are an important research direction in the field of solid-state lithium batteries by virtue of their unique soft and hard segment structure, designability, performance cooperativity and good interface compatibility. At present, the room-temperature ion conductivity of the polymer electrolyte is difficult to raise, the room-temperature ion conductivity of the traditional Solid Polymer Electrolyte (SPE) is low, and the charge and discharge performance of the battery in a normal-temperature environment is severely restricted. When we try to improve the ionic conductivity of polymers, we often encounter the problem of difficult balance of mechanical properties with ionic conductivity. Development of a material system capable of simultaneously having high mechanical strength and good ion conductivity is still a challenge, and the relationship between the structure and the performance needs to be studied intensively to solve. From the performance design perspective of polyurethane elastomer, we can find that the good soft and hard segment synergistic mechanism can make it break through the inherent contradiction of conductivity-strength-safety. However, in view of the conventional polymer electrolyte system, the hard segment generally plays a role in improving mechanical properties and has lower ionic conductivity, but if an ether chain is introduced into a polyurethane hard segment structure, the mechanical properties of the polyurethane hard segment are reduced, so that reasonably combining the soft segment structure and the hard segment structure in polyurethane in a synergistic way enables the polyurethane to have good mechanical properties while having ionic conductivity as a whole, and the polyurethane electrolyte has become a challenge in the current polyurethane electrolyte. Disclosure of Invention Based on the above, the invention aims to provide a polyurethane elastomer and a preparation method thereof, wherein the chain extender is replaced by ether micromolecular dihydric alcohol, and the rigid structure of aromatic isocyanate is matched, so that the polyurethane elastomer can keep better mechanical properties under the condition that a soft segment is not designed, the soft segment structure is further designed, the soft segment structure of polyester-polyether-polyester triblock is introduced, so that the distribution of the soft segment and the hard segment in isocyanate is more uniform, the mechanical properties of the prepared polyurethane elastomer are obviously improved, and the ionic conductivity is further improved due to the good ionic conductivity of an ester group, so that the common improvement of the ionic conductivity and the mechanical properties is realized. The technical scheme of the invention is realized by the following steps: A polyurethane elastomer is prepared from polyester-polyether-polyester triblock diol, aromatic isocyanate and micromolecular diol through a prepolymer method, wherein the molecular chain of the micromolecular diol comprises ether bonds. According to the polyurethane elastomer, the chain extender is replaced by the ether micromolecule dihydric alcohol and is matched with the rigid structure of the aromatic isocyanate, so that the polyurethane elastomer can keep better mechanical properties under the condition that a soft segment is not designed, the soft segment structure is further designed, the soft segment structure of the polyester-polyether-polyester triblock is introduced, so that the distribution of the soft segment and the hard segment in the isocyanate is more uniform, the mechanical properties of the prepared polyurethane elastomer are obviously improved, and the ionic conductivity is further improved due to the good ionic conductivity of the ester group, so that the common improvem