Use of a carbon dioxide-based terpolymer in the preparation of pressure sensitive adhesives

Abstract

The application relates to the technical field of pressure-sensitive adhesive, in particular to application of a carbon dioxide-based ternary copolymer in preparation of pressure-sensitive adhesive; the carbon dioxide-based ternary copolymer has a structure shown in formula I. In the application, the carbon dioxide-based ternary copolymer uses carbon dioxide as raw material, relieves the greenhouse effect, meets the demand of sustainable development, and the obtained carbon dioxide-based polycarbonate has degradable capacity. The carbon dioxide-based ternary copolymer can be directly used as pressure-sensitive adhesive without additional tackifier, plasticizer and other auxiliaries. The pressure-sensitive adhesive provided by the application has adjustable initial adhesion, holding adhesion and peeling strength, and shows performance comparable to or even surpassing that of commercial pressure-sensitive adhesive. The carbon dioxide-based ternary copolymer can produce different adjustments on the synthesized pressure-sensitive adhesive by selecting different types of third monomers, can reduce the glass transition temperature of the obtained material, meets the use environment requirement of the pressure-sensitive adhesive, and adjusts the performance of the pressure-sensitive adhesive.

Description

Technical Field

[0001] This invention relates to the field of pressure-sensitive adhesive technology, and more particularly to the application of a carbon dioxide-based terpolymer in the preparation of pressure-sensitive adhesives. Background Technology

[0002] Pressure-sensitive adhesives (PSAs) are adhesives that bond with a substrate under pressure, and are widely used in packaging, automotive parts, medical devices, and electronic products. The viscoelasticity of PSAs refers to their ability to combine adhesion and shear resistance, representing a balance between these seemingly contradictory properties. Currently available commercially available PSAs primarily consist of polyacrylates, rubber, and silicone. These traditional adhesives are mostly derived from petrochemical resources and are non-degradable. Furthermore, they require the addition of tackifiers and additives to improve their viscoelastic properties. Therefore, the development of sustainable polymeric PSAs has become a mainstream research focus.

[0003] Carbon dioxide is inexpensive, widely available, and non-toxic, yet it is a major contributor to the greenhouse effect. In recent decades, massive carbon dioxide emissions have caused severe environmental damage. Therefore, effectively utilizing carbon dioxide to turn waste into treasure and reducing its emissions and concentration in the environment has become a global issue affecting the sustainable development of human society. Over the past few decades, there has been extensive research on using carbon dioxide as a raw material to prepare green chemical products. It has been used in the chemical industry to produce urea, carboxylic acids, methanol, cyclic carbonates, and polycarbonates. Among these, the copolymerization of carbon dioxide and epoxides under the action of a catalyst to prepare carbon dioxide-based polycarbonates and carbon dioxide-based polyols represents a new approach to carbon dioxide fixation, showing potential applications in packaging materials, coatings, adhesives, and many other fields.

[0004] Due to the high stability and low reactivity of carbon dioxide, numerous catalytic systems have been explored over the past few decades to catalyze the reaction of carbon dioxide with epoxides. These include organic catalysts and metal-based catalysts such as K, Mg, Ca, Fe, Cr, Zn, Al, and rare earth metals. Among these studies, Salen-Co catalysts (CN105618141A, CN105665022A, CN101940947A, CN101905171A, CN116874390A, CN116726994A, CN115894347A, CN116850904A, CN115028789A, CN114713287A, etc.) have demonstrated excellent performance in the copolymerization reaction of epoxides and carbon dioxide. Catalysts such as Salen-Co can catalyze the random copolymerization of carbon dioxide and epoxides in a completely alternating manner to prepare carbon dioxide-based poly(carbonate-ether). The resulting polymers have different viscoelasticities depending on their molecular weight and carbonate unit content, and also have sustainability.

[0005] MWGrinstaff et al. used carbon dioxide / propylene oxide / glycidyl butyrate as comonomers via [S,S]-[SalcyCo] III A DNP / DNP catalyst synthesized a completely alternating random copolymer. This polymer can be used in pressure-sensitive adhesives and is biodegradable, but its initial tack is better at 37°C, limiting its temperature range (Nat. Commun., 2019, 10, 5478). CK Williams et al. prepared triblock copolymers based on a Robson ligand-based binuclear catalyst. The resulting polymers exhibited good adhesive properties; however, block copolymers have stringent requirements for catalyst selection, and their adhesive strength range is narrow, making significant performance tuning difficult (Angew. Chem. Int. Ed. 2020, 59, 1–7). HJ Kim et al. synthesized a novel aliphatic polyester polycaprolactone (PPDCL) with long alkyl substituents using cashew nut shell lactone as a raw material via ring-opening transesterification. The resulting polyester exhibits adhesive properties competitive with many common commercial adhesives. This ABA triblock copolymer is hydrolyzable and degradable, but it needs to be mixed with renewable tackifiers during use to produce sustainable pressure-sensitive adhesive materials (ACS Sustainable Chem. Eng., 2020, 8, 12036-12044).

[0006] In summary, existing commercially available pressure-sensitive adhesives are non-degradable; degradable pressure-sensitive adhesives still have the following problems: extraction and synthesis of materials are difficult and complex, costs are high, and additional tackifiers are required. Summary of the Invention

[0007] In view of this, the technical problem to be solved by the present invention is to provide an application of carbon dioxide-based terpolymer in the preparation of pressure-sensitive adhesive. The pressure-sensitive adhesive provided by the present invention is biodegradable and does not require the addition of other additives such as tackifiers and plasticizers. The pressure-sensitive adhesive of the present invention has adjustable initial tack, holding power and peel strength, and exhibits performance comparable to or even exceeding that of commercial pressure-sensitive adhesives.

[0008] This invention provides an application of carbon dioxide-based terpolymer in the preparation of pressure-sensitive adhesives;

[0009] The carbon dioxide-based terpolymer has the structure shown in Formula I;

[0010]

[0011] In Equation I, 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000;

[0012] The R1 and R2 are independently selected from C1 to C10 alkyl, C1 to C10 alkoxy, C1 to C10 substituted alkoxy; C1 to C10 alkyl glycidyl ether, C1 to C10 aryl glycidyl ether, C1 to C10 cycloalkanes or halogens.

[0013] Preferably, R1 and R2 are independently selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, allyl, or PEG groups.

[0014] Preferably, in the carbon dioxide-based terpolymer having the structure shown in Formula I, the mass content of the carbonate unit is 85% to 99%, and the mass content of the ether segment is 1% to 15%.

[0015] Preferably, the carbon dioxide-based terpolymer having the structure shown in Formula I is prepared by terpolymerization of carbon dioxide and epoxide;

[0016] The epoxides include two of the following: propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, cyclohexane oxide, 1,2-epoxyhexane, 1,2-epoxycyclopentane, epichlorohydrin, glycidyl methacrylate (PEGMA), methyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, styrene oxide, 1,2-epoxy-4-vinylcyclohexane, 2-vinyl ethylene oxide, and 2-[2-(2-methoxyethoxy)ethoxy]ethyl glycidyl ether.

[0017] Preferably, the main catalyst for the ternary copolymerization is a Salen-Co catalyst, having the structure shown in Formula II;

[0018]

[0019] Preferably, the cocatalyst for the ternary copolymerization is bis(triphenylphosphine)trifluoroacetate ammonium PPNTFA, which has the structure shown in Formula III;

[0020]

[0021] Preferably, the molar ratio of the co-catalyst to the main catalyst is 0 to 2:1;

[0022] The molar ratio of the main catalyst to the epoxide is 1:1000 to 5000.

[0023] Preferably, the carbon dioxide pressure of the ternary copolymer is 0-20 MPa, and not 0.

[0024] Preferably, the ternary copolymerization temperature is 20–30°C and the time is 6–72 h.

[0025] The present invention also provides a pressure-sensitive adhesive, which is prepared from a carbon dioxide-based terpolymer;

[0026] The carbon dioxide-based terpolymer has the structure shown in Formula I;

[0027]

[0028] In Equation I, 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000;

[0029] The R1 and R2 are independently selected from C1 to C10 alkyl, C1 to C10 alkoxy, C1 to C10 substituted alkoxy; C1 to C10 alkyl glycidyl ether, C1 to C10 aryl glycidyl ether, C1 to C10 cycloalkanes or halogens.

[0030] This invention provides an application of a carbon dioxide-based terpolymer in the preparation of pressure-sensitive adhesives; the carbon dioxide-based terpolymer has the structure shown in Formula I;

[0031]

[0032] In Equation I, 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000;

[0033] The R1 and R2 are independently selected from C1 to C10 alkyl, C1 to C10 alkoxy, C1 to C10 substituted alkoxy; C1 to C10 alkyl glycidyl ether, C1 to C10 aryl glycidyl ether, C1 to C10 cycloalkanes or halogens.

[0034] In this invention, the carbon dioxide-based terpolymer uses carbon dioxide as a raw material, mitigating the greenhouse effect and meeting the needs of sustainable development. Simultaneously, the resulting carbon dioxide-based polycarbonate is biodegradable. The carbon dioxide-based terpolymer can be used directly as a pressure-sensitive adhesive without the need for additional tackifiers, plasticizers, or other additives. The pressure-sensitive adhesive provided by this invention exhibits adjustable initial tack, holding power, and peel strength, demonstrating performance comparable to or even exceeding that of commercial pressure-sensitive adhesives. By selecting different types of third monomers, the carbon dioxide-based terpolymer can produce different adjustments to the synthesized pressure-sensitive adhesive, lowering the glass transition temperature of the resulting material to meet the environmental requirements for use, thereby regulating the performance of the pressure-sensitive adhesive. Attached Figure Description

[0035] Figure 1 The hydrogen NMR spectrum of the polymer prepared in Example 1 of this invention;

[0036] Figure 2 The GPC spectrum of the polymer prepared in Example 5 of this invention;

[0037] Figure 3 180° peel test curve of the pressure-sensitive adhesive prepared for PPC5 of the present invention;

[0038] Figure 4 A DSC schematic diagram of the pressure-sensitive adhesive prepared by PPC5 according to the present invention;

[0039] Figure 5 A schematic diagram of the thermal decomposition of the pressure-sensitive adhesive prepared by PPC5 according to the present invention;

[0040] Figure 6 A rheological schematic diagram of the pressure-sensitive adhesive prepared by PPC5 according to the present invention;

[0041] Figure 7 The 180° peel strength curve of the 3M Scotch tape in Comparative Example 1;

[0042] Figure 8 The 180° peel strength curve of the Japanese Nitto tape in Comparative Example 2 is shown. Detailed Implementation

[0043] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] This invention provides an application of carbon dioxide-based terpolymer in the preparation of pressure-sensitive adhesives; specifically, it can be used as a raw material component in the preparation of pressure-sensitive adhesives; or it can be used directly as a pressure-sensitive adhesive.

[0045] The carbon dioxide-based terpolymer has the structure shown in Formula I;

[0046]

[0047] In Equation I, 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000;

[0048] The R1 and R2 are independently selected from C1 to C10 alkyl, C1 to C10 alkoxy, C1 to C10 substituted alkoxy; C1 to C10 alkyl glycidyl ether, C1 to C10 aryl glycidyl ether, C1 to C10 cycloalkanes or halogens.

[0049] The carbon dioxide-based terpolymer in this invention is polycarbonate, which has a completely alternating structure.

[0050] In some embodiments of the present invention, R1 and R2 are independently selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, allyl, or PEG groups.

[0051] In some embodiments of the present invention, the carbon dioxide-based terpolymer having the structure shown in Formula I has a carbonate unit content of 85% to 99% by mass and an ether segment content of 1% to 15% by mass.

[0052] In some embodiments of the present invention, the carbon dioxide-based terpolymer having the structure shown in Formula I has the structure shown in Formula (1):

[0053]

[0054] Where 5≤m≤5000, 5≤n≤5000.

[0055] In some embodiments of the present invention, the carbon dioxide-based terpolymer having the structure shown in Formula I is prepared by terpolymerization of carbon dioxide and an epoxide; the epoxide is selected from two of the following: propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, cyclohexane oxide, 1,2-epoxyhexane, 1,2-epoxyhexane, 1,2-epoxycyclopentane, epichlorohydrin, glycidyl methacrylate (PEGMA), methyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, styrene oxide, 1,2-epoxy-4-vinylcyclohexane, 2-vinyl ethylene oxide, and 2-[2-(2-methoxyethoxy)ethoxy]ethyl glycidyl ether (ME3GE).

[0056] The main catalyst for the ternary copolymerization is a Salen-Co catalyst, which has the structure shown in Formula II;

[0057]

[0058] The present invention does not impose any special restrictions on the source of the Salen-Co catalyst. It can be prepared by conventional methods or by following the methods disclosed in patent documents CN105618141A, CN105665022A, CN101940947A, CN101905171A, CN116874390A, CN116726994A, CN115894347A, CN116850904A, CN115028789A, and CN114713287A.

[0059] The cocatalyst for the ternary copolymerization is bis(triphenylphosphine)trifluoroacetate ammonium PPNTFA, which has the structure shown in Formula III;

[0060]

[0061] In some embodiments of the present invention, the preparation method of the bis(triphenylphosphine)trifluoroacetate ammonium (PPNTFA) includes the following steps:

[0062] An aqueous solution of NaX was mixed with PPNCl and reacted at 45–55 °C. The resulting turbid liquid was filtered while hot, and the filter residue was recrystallized in dichloromethane to obtain the product PPNX; wherein, X = TFA.

[0063]

[0064] The molar ratio of NaX to PPNCl is 1:1. The reaction temperature is 50°C; the reaction time is 1–3 hours, for example, 2 hours. The recrystallization is performed three times.

[0065] The molar ratio of the co-catalyst to the main catalyst is 0 to 2:1, for example, 1:1.

[0066] The molar ratio of the main catalyst to the epoxide is 1:1000 to 5000, for example, 1:2000.

[0067] The carbon dioxide pressure of the ternary copolymer is 0-20 MPa, and is not 0; for example, 2 MPa, 4 MPa, 6 MPa.

[0068] The ternary copolymerization is carried out at a temperature of 20–30°C, for example, 25°C, and for a time of 6–72 hours, for example, 24 hours. The ternary copolymerization is performed under stirring conditions, and the stirring speed is 50–1000 rpm, for example, 500 rpm.

[0069] After the ternary copolymerization is completed, the process also includes cooling in an ice-water bath.

[0070] The carbonate unit content and ether segment content of the polycarbonate can be adjusted by the co-catalyst and carbon dioxide pressure.

[0071] The present invention also provides a pressure-sensitive adhesive, which is prepared from a carbon dioxide-based terpolymer;

[0072] The carbon dioxide-based terpolymer is the carbon dioxide-based terpolymer described above.

[0073] In some embodiments of the present invention, the method for preparing the pressure-sensitive adhesive includes the following steps:

[0074] A) The carbon dioxide-based terpolymer is mixed with a solvent to obtain a polymer solution;

[0075] B) The polymer solution is uniformly coated onto the substrate, and the solvent is removed to obtain a pressure-sensitive adhesive;

[0076] The carbon dioxide-based terpolymer is the carbon dioxide-based terpolymer described above.

[0077] In step A):

[0078] In some embodiments of the present invention, the solvent is acetone.

[0079] In some embodiments of the present invention, the concentration of the polymer solution is 0.2 to 0.6 mg / mL; for example, 0.2 mg / mL, 0.4 mg / mL, or 0.6 mg / mL.

[0080] In step B):

[0081] In some embodiments of the present invention, the coating is performed using a wire bar coater with a specification of 50 μm.

[0082] In some embodiments of the present invention, the substrate is a PET film, specifically an A4-sized PET film with a thickness of 50 μm.

[0083] In some embodiments of the present invention, the method for removing the solvent includes:

[0084] Allow the solvent to evaporate and be removed by standing in a fume hood for 10–14 hours at room temperature.

[0085] Beneficial effects:

[0086] 1) The carbon dioxide-based terpolymer uses carbon dioxide as a raw material, which can alleviate the greenhouse effect and meet the needs of sustainable development. At the same time, the resulting carbon dioxide-based polycarbonate has degradability.

[0087] 2) The carbon dioxide-based terpolymer can be used directly as a pressure-sensitive adhesive without the need for additional tackifiers, plasticizers, or other additives, and possesses good and adjustable peel strength (0.05–5 N / cm). Its molecular weight ranges from 5 kg / mol to 200 kg / mol, and the mass content of carbonate units ranges from 85% to 99%, all exhibiting considerable peel strength (0.4–18 N / cm). It also demonstrates adjustable initial tack (between ball sizes 1 and 7) and high holding power (up to 100 hours).

[0088] 3) The pressure-sensitive adhesive prepared by this invention has adjustable initial tack, holding power and peel strength, and exhibits performance comparable to or even exceeding that of commercial pressure-sensitive adhesives.

[0089] 4) By selecting different types of third monomers, the carbon dioxide-based terpolymer can produce different adjustments to the synthesized pressure-sensitive adhesive, thereby reducing the glass transition temperature of the obtained material and meeting the environmental requirements for the use of the pressure-sensitive adhesive, thus adjusting the performance of the pressure-sensitive adhesive.

[0090] The present invention does not impose any special restrictions on the source of the raw materials used above, and they can be commercially available.

[0091] To further illustrate the present invention, the following detailed description of the application of a carbon dioxide-based terpolymer provided by the present invention in the preparation of pressure-sensitive adhesives is provided in conjunction with embodiments, but it should not be construed as limiting the scope of protection of the present invention.

[0092] Preparation of Salen-Co catalysts with the structure shown in Formula II:

[0093]

[0094] The ligand Ln (0.01 mol) was dissolved in a three-necked flask containing 150 mL of dichloromethane and stirred at room temperature. After the ligand was completely dissolved, an anhydrous ethanol solution containing 0.012 mol of Co(OAc)₂ was added, and stirring was continued for 1 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was repeatedly washed with anhydrous ethanol solution to obtain a red solid for later use. The red solid (0.01 mmol) and CF₃COOH (0.01 mmol) were dissolved in 20 mL of dichloromethane, oxygen was bubbled through, and the mixture was stirred in the dark at room temperature for 2 h. After the reaction was complete, the mixture was filtered, and the solvent in the filtrate was removed by rotary evaporation to obtain the crude product. The crude product was recrystallized with diethyl ether and n-hexane to obtain the final product. Then, after dissolving in dichloromethane, 1 mL of trifluoroacetic acid was immediately added and stirred overnight in air at room temperature. The solvent was then evaporated by rotary evaporation at 20–25 °C. The solid was dissolved in dichloromethane and recrystallized in n-hexane. The final filtered solid was the final product (Salen-Co catalyst with the structure shown in Formula II).

[0095] ME3GE has the structure shown in Formula IV;

[0096]

[0097] Preparation of ME3GE:

[0098] Epichlorohydrin (92.5 g, 1.0 mol) and sodium hydroxide (60.0 g, 1.5 mmol) were added to a round-bottom flask. While stirring at room temperature, 1.0 mol of triethylene glycol monomethyl ether (TME) was added dropwise. After the addition was complete, the mixture was stirred at room temperature for another 3 h. After stirring, the reaction mixture was filtered to remove excess NaOH and the formed NaCl. The remaining liquid was colorless and transparent, or a slightly yellow transparent liquid. The product was then dried with MgSO4 and further dried by vacuum distillation with CaH2.

[0099] Preparation of PPNTFA:

[0100] Dissolve NaX (10 mmol) in 10 mL of deionized water, then add PPNCl (5.74 g, 10 mmol), react at 50 °C for 2 h, filter the resulting turbid liquid while hot, and recrystallize the filter residue from dichloromethane three times to obtain the product PPNX; where X = TFA;

[0101]

[0102] Preparation Example 1

[0103] Using Salen-Co catalyst with the structure shown in Formula II as the main catalyst, PPNTFA with the structure shown in Formula III as the co-catalyst, and propylene oxide (PO) as the epoxy monomer, 2000 eq. of propylene oxide, 200 eq. of ME3GE, 1.1 eq. of Salen-Co catalyst and 1.1 eq. of PPNTFA were added to a 50 mL reactor in a glove box.

[0104] The reactor was placed in a 25°C water bath and charged with 2 MPa of carbon dioxide. The mixture was stirred at 500 rpm for 24 h. After the reaction, it was cooled in an ice-water bath for 15 min. A portion of the sample was tested for 1H NMR spectroscopy. The remaining sample was dissolved in dichloromethane and precipitated in a 5 wt% hydrochloric acid-methanol solution. The resulting polymer was filtered and dried for later use. The polymer has the structure shown in formula (1) (where 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000):

[0105]

[0106] Figure 1 The image shows the hydrogen NMR spectrum of the polymer prepared in Example 1 of this invention.

[0107] GPC testing showed that its molecular weight was 70.8 kg / mol and its molecular weight distribution was 1.35; NMR testing showed that its conversion rate was 95%, its carbonate unit content was 99%, and its polymer selectivity was 99%. It is denoted as PPC1.

[0108] Preparation Example 2

[0109] Using Salen-Co catalyst with the structure shown in Formula II as the main catalyst, PPNTFA with the structure shown in Formula III as the co-catalyst, and propylene oxide (PO) as the epoxy monomer, 2000 eq. of propylene oxide, 200 eq. of ME3GE, 1.1 eq. of Salen-Co catalyst and 1.1 eq. of PPNTFA were added to a 50 mL reactor in a glove box.

[0110] The reactor was placed in a 25°C water bath and charged with 4 MPa of carbon dioxide. The reaction was stirred at 500 rpm for 24 h. After the reaction was completed, it was cooled in an ice-water bath for 15 min. A portion of the sample was tested for 1H NMR spectrum. The remaining sample was dissolved in dichloromethane and precipitated in a 5 wt% hydrochloric acid methanol solution (to remove the catalyst from the polymer). The resulting polymer was filtered and dried for later use. The polymer has the structure shown in formula (1) (wherein 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000).

[0111] GPC testing showed that its molecular weight was 71.9 kg / mol and its molecular weight distribution was 1.33; NMR testing showed that its conversion rate was 97%, its carbonate unit content was 95%, and its polymer selectivity was 99%. It is denoted as PPC2.

[0112] Preparation Example 3

[0113] Using Salen-Co catalyst with the structure shown in Formula II as the main catalyst, PPNTFA with the structure shown in Formula III as the co-catalyst, and propylene oxide (PO) as the epoxy monomer, 2000 eq. of propylene oxide, 200 eq. of ME3GE, 1.1 eq. of Salen-Co catalyst and 1.1 eq. of PPNTFA were added to a 50 mL reactor in a glove box.

[0114] The reactor was placed in a 25°C water bath and charged with 6 MPa of carbon dioxide. The reaction was stirred at 500 rpm for 24 h. After the reaction was completed, it was cooled in an ice-water bath for 15 min. A portion of the sample was tested for 1H NMR spectrum. The remaining sample was dissolved in dichloromethane and precipitated in a 5 wt% hydrochloric acid methanol solution. The resulting polymer was filtered and dried for later use. The polymer has the structure shown in formula (1) (wherein 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000).

[0115] GPC testing showed that its molecular weight was 71.2 kg / mol and its molecular weight distribution was 1.35; NMR testing showed that its conversion rate was 94%, its carbonate unit content was 95%, and its polymer selectivity was 99%. It is designated as PPC3.

[0116] Preparation Example 4

[0117] Using Salen-Co catalyst with the structure shown in Formula II as the main catalyst, PPNTFA with the structure shown in Formula III as the co-catalyst, and propylene oxide (PO) as the epoxy monomer, 4000 eq. of propylene oxide, 500 eq. of ME3GE, 2.25 eq. of Salen-Co catalyst and 2.25 eq. of PPNTFA were added to a 50 mL reactor in a glove box.

[0118] The reactor was placed in a 25°C water bath and charged with 6 MPa of carbon dioxide. The reaction was stirred at 500 rpm for 24 h. After the reaction was completed, it was cooled in an ice-water bath for 15 min. A portion of the sample was tested for 1H NMR spectrum. The remaining sample was dissolved in dichloromethane and precipitated in a 5 wt% hydrochloric acid methanol solution. The resulting polymer was filtered and dried for later use. The polymer has the structure shown in formula (1) (wherein 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000).

[0119] GPC testing showed that its molecular weight was 67.4 kg / mol and its molecular weight distribution was 1.31; NMR testing showed that its conversion rate was 96%, its carbonate unit content was 95%, and its polymer selectivity was 99%. It is designated as PPC4.

[0120] Preparation Example 5

[0121] Using Salen-Co catalyst with the structure shown in Formula II as the main catalyst, PPNTFA with the structure shown in Formula III as the co-catalyst, and propylene oxide (PO) as the epoxy monomer, 3000 eq. of propylene oxide, 500 eq. of ME3GE, 1.75 eq. of Salen-Co catalyst and 1.75 eq. of PPNTFA were added to a 50 mL reactor in a glove box.

[0122] The reactor was placed in a 25°C water bath and charged with 6 MPa of carbon dioxide. The reaction was stirred at 500 rpm for 24 h. After the reaction was completed, it was cooled in an ice-water bath for 15 min. A portion of the sample was tested for 1H NMR spectrum. The remaining sample was dissolved in dichloromethane and precipitated in a 5 wt% hydrochloric acid methanol solution. The resulting polymer was filtered and dried for later use. The polymer has the structure shown in formula (1) (wherein 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000).

[0123] Figure 2 The image shows the GPC spectrum of the polymer prepared in Example 5 of this invention.

[0124] GPC testing showed that its molecular weight was 62.2 kg / mol and its molecular weight distribution was 1.36; NMR testing showed that its conversion rate was 93%, its carbonate unit content was 94%, and its polymer selectivity was 99%. It is designated as PPC5.

[0125] Preparation Example 6

[0126] Using Salen-Co catalyst with the structure shown in Formula II as the main catalyst, PPNTFA with the structure shown in Formula III as the co-catalyst, and propylene oxide (PO) as the epoxy monomer, 2000 eq. of propylene oxide, 400 eq. of ME3GE, 1.2 eq. of Salen-Co catalyst and 1.2 eq. of PPNTFA were added to a 50 mL reactor in a glove box.

[0127] The reactor was placed in a 25°C water bath and charged with 6 MPa of carbon dioxide. The reaction was stirred at 500 rpm for 24 h. After the reaction was completed, it was cooled in an ice-water bath for 15 min. A portion of the sample was tested for 1H NMR spectrum. The remaining sample was dissolved in dichloromethane and precipitated in a 5 wt% hydrochloric acid methanol solution. The resulting polymer was filtered and dried for later use. The polymer has the structure shown in formula (1) (wherein 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000).

[0128] GPC testing showed that its molecular weight was 56.1 kg / mol and its molecular weight distribution was 1.31; NMR testing showed that its conversion rate was 94%, its carbonate unit content was 95%, and its polymer selectivity was 99%. It is designated as PPC6.

[0129] Preparation Example 7

[0130] Using Salen-Co catalyst with the structure shown in Formula II as the main catalyst, PPNTFA with the structure shown in Formula III as the co-catalyst, and propylene oxide (PO) as the epoxy monomer, 2000 eq. of propylene oxide, 500 eq. of ME3GE, 1.25 eq. of Salen-Co catalyst and 1.25 eq. of PPNTFA were added to a 50 mL reactor in a glove box.

[0131] The reactor was placed in a 25°C water bath and charged with 6 MPa of carbon dioxide. The reaction was stirred at 500 rpm for 24 h. After the reaction was completed, it was cooled in an ice-water bath for 15 min. A portion of the sample was tested for 1H NMR spectrum. The remaining sample was dissolved in dichloromethane and precipitated in a 5 wt% hydrochloric acid methanol solution. The resulting polymer was filtered and dried for later use. The polymer has the structure shown in formula (1) (wherein 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000).

[0132] GPC testing showed that its molecular weight was 46.3 kg / mol and its molecular weight distribution was 1.37; NMR testing showed that its conversion rate was 96%, its carbonate unit content was 95%, and its polymer selectivity was 99%. It is designated as PPC7.

[0133] Preparation Example 8

[0134] Using Salen-Co catalyst with the structure shown in Formula II as the main catalyst, PPNTFA with the structure shown in Formula III as the co-catalyst, and propylene oxide (PO) as the epoxy monomer, 2000 eq. of propylene oxide, 1000 eq. of ME3GE, 1.5 eq. of Salen-Co catalyst and 1.5 eq. of PPNTFA were added to a 50 mL reactor in a glove box.

[0135] The reactor was placed in a 25°C water bath and charged with 4 MPa of carbon dioxide. The reaction was stirred at 500 rpm for 24 h. After the reaction was completed, it was cooled in an ice-water bath for 15 min. A portion of the sample was tested for 1H NMR spectrum. The remaining sample was dissolved in dichloromethane and precipitated in a 5 wt% hydrochloric acid methanol solution. The resulting polymer was filtered and dried for later use. The polymer has the structure shown in formula (1) (wherein 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000).

[0136] GPC testing showed that its molecular weight was 39.4 kg / mol and its molecular weight distribution was 1.34; NMR testing showed that its conversion rate was 98%, its carbonate unit content was 95%, and its polymer selectivity was 99%. It is designated as PPC8.

[0137] Preparation and testing of pressure-sensitive adhesives:

[0138] Example 1

[0139] PPC1 was dissolved in acetone to prepare a polymer solution of 0.2 mg / mL. 4 mL of the 0.2 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then applied over the film, and the adhesive layer thickness was measured to be 5 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. The strips were placed on a 50 × 150 mm mirror stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial tack is 4-ball, its holding power is 0.5h, and its peel strength is 0.6N / cm.

[0140] Example 2

[0141] PPC1 was dissolved in acetone to prepare a polymer solution of 0.4 mg / mL. 4 mL of the 0.4 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then applied over the film, and the adhesive layer thickness was measured to be 10 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. The strips were placed on a 50 × 150 mm mirror stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial tack is 4-ball, its holding power is 0.7h, and its peel strength is 1.5N / cm.

[0142] Example 3

[0143] PPC1 was dissolved in acetone to prepare a polymer solution of 0.6 mg / mL. 4 mL of the 0.6 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then applied over the film, and the adhesive layer thickness was measured to be 15 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. These strips were placed on a 50 × 150 mm mirror-finish stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial tack is 4-ball, its holding power is 0.8h, and its peel strength is 2.1N / cm.

[0144] Example 4

[0145] PPC2 was dissolved in acetone to prepare a polymer solution of 0.2 mg / mL. 4 mL of the 0.2 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then applied over the film, and the adhesive layer thickness was measured to be 5 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. The strips were placed on a 50 × 150 mm mirror stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial tack is 3mm, its holding power is 2h, and its peel strength is 2.5N / cm.

[0146] Example 5

[0147] PPC3 was dissolved in acetone to prepare a polymer solution of 0.2 mg / mL. 4 mL of the 0.2 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then applied over the film, and the adhesive layer thickness was measured to be 5 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. The strips were placed on a 50 × 150 mm mirror-finish stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial tack is 3mm, its holding power is 8h, and its peel strength is 2.8N / cm.

[0148] Example 6

[0149] PPC4 was dissolved in acetone to prepare a polymer solution of 0.2 mg / mL. 4 mL of the 0.2 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then applied over the film, and the adhesive layer thickness was measured to be 5 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. The strips were placed on a 50 × 150 mm mirror-finish stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial tack is 3 for ball #3, its holding power is 5h, and its peel strength is 3.2N / cm.

[0150] Example 7

[0151] PPC5 was dissolved in acetone to prepare a polymer solution of 0.2 mg / mL. 4 mL of the 0.2 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then applied over the film, and the adhesive layer thickness was measured to be 5 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. The strips were placed on a 50 × 150 mm mirror-finish stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial tack is 2 for ball #2, its holding power is 40h, and its peel strength is 5N / cm.

[0152] Figure 3 The 180° peel test curve of the pressure-sensitive adhesive prepared for PPC5 of the present invention. From... Figure 3 It can be seen that the peel strength of the pressure-sensitive adhesive is 5 N / cm.

[0153] Figure 4 This is a DSC schematic diagram of the pressure-sensitive adhesive prepared from PPC5 according to the present invention. Figure 4 It is known that the glass transition temperature of the pressure-sensitive adhesive is -23℃.

[0154] Figure 5 This is a schematic diagram illustrating the thermal decomposition of the pressure-sensitive adhesive prepared from PPC5 according to the present invention. Figure 5It is known that the thermal decomposition temperature of the pressure-sensitive adhesive is 220℃, and the maximum decomposition temperature is 236 / 295℃.

[0155] Figure 6 This is a rheological schematic diagram of the pressure-sensitive adhesive prepared from PPC5 according to the present invention. Figure 6 It can be seen that within the application frequency range of 0.01Hz to 100Hz for pressure-sensitive adhesives, the storage modulus and loss modulus of polymer PPC5 are at around 10. 3 ~10 6 Between Pa, the modulus requirements for pressure-sensitive adhesives are met. 3 ~10 6 Pa.

[0156] Example 8

[0157] PPC6 was dissolved in acetone to prepare a polymer solution of 0.2 mg / mL. 4 mL of the 0.2 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then applied over the film, and the adhesive layer thickness was measured to be 5 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. The strips were placed on a 50 × 150 mm mirror-finish stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial adhesion is 1 ball, its holding power is 70h, and its peel strength is 8N / cm.

[0158] Example 9

[0159] PPC7 was dissolved in acetone to prepare a polymer solution of 0.2 mg / mL. 4 mL of the 0.2 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then placed on top, and the adhesive layer thickness was measured to be 5 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. The strips were placed on a 50 × 150 mm mirror stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial tack is 1 ball, its holding power is 150 h, and its peel strength is 14 N / cm.

[0160] Example 10

[0161] PPC8 was dissolved in acetone to prepare a polymer solution of 0.2 mg / mL. 4 mL of the 0.2 mg / mL polymer solution was uniformly coated onto a 50 μm thick PET film (A4 size) using a 50 μm wire bar coater. The film was then left to stand in a fume hood at room temperature for 12 hours to allow the solvent to evaporate. A 50 μm thick PET release film was then applied over the film, and the adhesive layer thickness was measured to be 5 μm. The film was then cut into 25 × 300 mm strips using a 25 mm width cutter. The strips were placed on a 50 × 150 mm mirror-finish stainless steel plate and rolled twice evenly and slowly using a 2 kg steel roller. After standing for 6 hours, the initial tack (according to GB / T 4852-2002), holding power (according to GB / T 4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested. Test results show that its initial tack is 1 ball, its holding power is 200h, and its peel strength is 18N / cm.

[0162] Comparative Example 1

[0163] Commercially available 3M Scotch tape uses polyacrylate polymers as adhesives, and also contains various additives such as tackifiers and plasticizers. It is non-degradable.

[0164] Its initial tack (according to GB / T 4852-2002), holding power (according to GB / T4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested respectively. The test results show that its initial tack is 6-ball size, its holding power is 27h, and its peel strength is 3.5N / cm.

[0165] Figure 7The figure shows the 180° peel strength curve of the 3M Scotch tape in Comparative Example 1. According to the test curve results, the 180° peel strength of the 3M Scotch tape is 3.5 N / cm, and the peel strength of the example is superior to that of the comparative example.

[0166] Comparative Example 2

[0167] Commercially available Japanese Nitto tape has a peel strength of 3 N / cm. It uses polyacrylate polymers as adhesives and adds various additives such as tackifiers and plasticizers. It is non-degradable.

[0168] Its initial tack (according to GB / T 4852-2002), holding power (according to GB / T4851-2014), and 180° peel strength (according to GB / T 2192-2014) were tested respectively. The test results show that its initial tack is 7-ball, its holding power is greater than 100h, and its peel strength is 3N / cm.

[0169] Figure 8 The figure shows the 180° peel strength curve of the Japanese Nitto tape in Comparative Example 2. According to the test curve results, the 180° peel strength of the Nitto tape is 3.2 N / cm, and the peel strength of the example is better than that of the comparative example.

[0170] The descriptions of the above embodiments are merely illustrative of the methods and core ideas of the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The application of a carbon dioxide-based terpolymer in the preparation of pressure-sensitive adhesives; The carbon dioxide-based terpolymer is prepared by terpolymerization of carbon dioxide, propylene oxide and 2-[2-(2-methoxyethoxy)ethoxy]ethyl glycidyl ether; and has the structure shown in formula (1); Formula (1); In equation (1), 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000; In the carbon dioxide-based terpolymer, the mass content of carbonate units is 85%~99%, and the mass content of ether segments is 1%~15%. The main catalyst for the ternary copolymerization is a Salen-Co catalyst, which has the structure shown in Formula II; Formula II; The cocatalyst for the ternary copolymerization is bis(triphenylphosphine)trifluoroacetate ammonium PPNTFA, which has the structure shown in Formula III; Formula III; The molar ratio of the co-catalyst to the main catalyst is 0~2:1; The molar ratio of the main catalyst to the epoxide is 1:1000~5000.

2. The application according to claim 1, characterized in that, The carbon dioxide pressure of the ternary copolymer is 0~20MPa, and is not 0.

3. The application according to claim 1, characterized in that, The ternary copolymerization is carried out at a temperature of 20-30°C for 6-72 hours.

4. A pressure-sensitive adhesive, said pressure-sensitive adhesive being prepared from a carbon dioxide-based terpolymer; The carbon dioxide-based terpolymer is prepared by terpolymerization of carbon dioxide, propylene oxide and 2-[2-(2-methoxyethoxy)ethoxy]ethyl glycidyl ether; and has the structure shown in formula (1); Equation (1); In equation (1), 5 ≤ m ≤ 5000, 5 ≤ n ≤ 5000; In the carbon dioxide-based terpolymer, the mass content of carbonate units is 85%~99%, and the mass content of ether segments is 1%~15%. The main catalyst for the ternary copolymerization is a Salen-Co catalyst, which has the structure shown in Formula II; Formula II; The cocatalyst for the ternary copolymerization is bis(triphenylphosphine)trifluoroacetate ammonium PPNTFA, which has the structure shown in Formula III; Formula III; The molar ratio of the co-catalyst to the main catalyst is 0~2:1; The molar ratio of the main catalyst to the epoxide is 1:1000~5000.

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