Transparent fully-hydrogenated polystyrene-pentadiene resin and preparation method thereof

Abstract

The invention discloses a transparent fully hydrogenated polystyrene-pentadiene resin and a preparation method thereof, the transparent fully hydrogenated polystyrene-pentadiene resin is obtained by completely hydrogenating a block copolymer with the following structure: # imgabs0 #, S1 and S2 are styrene homopolymerized blocks, SP is a styrene and pentadiene alternating copolymer block, S is a styrene and pentadiene alternating copolymer block, and S is a styrene and pentadiene alternating copolymer block. The hydrogenation rates of a benzene ring unit and an m-pentadiene unit in the segmented copolymer are both greater than 99%. The resin has the characteristics of good chemical stability, ultraviolet light resistance, heat resistance, weather resistance, ozone resistance, relatively high toughness, high strength and the like, and is particularly suitable for preparing optical, electronic, traffic and transportation, remote sensing scientific and technical equipment, packaging materials, instrument panels and the like.

Description

Technical Field

[0001] The invention relates to a resin, in particular to a transparent fully hydrogenated polystyrene-isopentadiene resin and a preparation method thereof, belonging to the technical field of resin materials. Background Art

[0002] Common unsaturated polymer materials usually have poor heat resistance, UV resistance and yellowing resistance due to the presence of unsaturated double bonds (such as benzene ring double bonds, diene double bonds, etc.). Hydrogenation modification of unsaturated polymers is an effective way to improve their performance.

[0003] The fully saturated polycyclohexylethylene (PVCH) obtained by hydrogenating the double bonds of the benzene ring of polystyrene (PS) has a glass transition temperature of 147°C, which significantly improves the heat resistance and UV resistance of PS. It has the advantages of high light transmittance, light weight, high glass transition temperature, low water absorption, good optical properties, high strength, and easy molding. It can be used in optical materials, electronics, transportation, remote sensing science and technology and other fields. The hydrogenation of the double bonds in the benzene ring of polystyrene is more difficult than the hydrogenation of the carbon-carbon double bonds of olefins. It usually requires high temperature, high pressure and other conditions. It is difficult to hydrogenate it with traditional homogeneous catalysts. At present, the hydrogenation of PS mainly adopts heterogeneous hydrogenation.

[0004] Chinese patent (CN104140480A) discloses a method for hydrogenating polystyrene by loading an active component Pd (or Pt, Rh) on a hollow silica microsphere carrier having macropores (pore size 250-650 nm) on the surface. The amount of catalyst added is 10-50% of the polystyrene. Under the conditions of temperature of 100-170°C and hydrogen pressure of 5-15 MPa, the hydrogenation time is 5-15 h. The degree of hydrogenation of the benzene ring of polystyrene reaches more than 91.3%. However, the use of a noble metal catalyst requires a large amount of catalyst added, high cost, long hydrogenation time, molecular chain degradation, and a benzene ring hydrogenation rate of less than 98%. A Chinese patent (CN115364876A) discloses a method for hydrogenating polystyrene by loading an active component Pt, an auxiliary agent, and a modifier on a carrier. The amount of catalyst added is 2 to 10% of the polystyrene. The temperature is 120 to 180°C, the hydrogen pressure is 1 to 5 MPa, and the hydrogenation time is 1 to 3 hours. The degree of hydrogenation of the polystyrene benzene ring reaches more than 96%. However, the use of a noble metal hydrogenation catalyst is costly.

[0005] At the same time, due to the influence of the cyclohexyl group on the PVCH molecular chain, the rigidity is large and the product is brittle, which affects the application of PVCH. In order to improve its brittle properties, dienes can be introduced to copolymerize with styrene to increase its product toughness, thereby reducing its brittleness. Chinese patent (CN105175659A) discloses a transparent hydrogenated polystyrene-b-random copolymerized diene / styrene resin and its preparation method. The resin is composed of a styrene block and a styrene and conjugated diene random copolymerization block. The C=C hydrogenation rate of the conjugated diene unit in the block copolymer reaches more than 98%. The preparation method is to first homopolymerize the styrene monomer under the initiation of alkyl lithium, and then randomly copolymerize the styrene, conjugated diene and divinylbenzene mixed monomers, and the copolymerization product is hydrogenated with a dichloro dithiocarbazine system. Random copolymerization of styrene, conjugated diene and divinylbenzene mixed monomers is complicated to control in order to ensure its random copolymerization. The dithiocarbazine system is used for hydrogenation, and only the diene C=C can be hydrogenated, and the hydrogenation rate of the benzene ring is less than 3%. U.S. Patent (US2018258276) discloses a fully hydrogenated polystyrene and conjugated diene multi-block copolymer, with a benzene ring hydrogenation rate greater than 99%, but uses precious metals and catalysts, and the hydrogenation pressure is high, the production is difficult to control, and the production cost is high. Summary of the invention

[0006] In view of the problems existing in the prior art, the first object of the present invention is to provide a transparent fully hydrogenated polystyrene-isopentadiene resin, which has the characteristics of good chemical stability, resistance to ultraviolet light, heat resistance, weather resistance, ozone resistance, high toughness and high strength, and is particularly suitable for the preparation of optical, electronic, transportation, remote sensing science and technology equipment, packaging materials and instrument panels.

[0007] The second object of the present invention is to provide a method for preparing the transparent fully hydrogenated polystyrene-piperylene resin which is simple to operate and has low production cost.

[0008] In order to achieve the above technical objectives, the present invention provides a transparent fully hydrogenated polystyrene-isopentadiene resin, which is obtained by fully hydrogenating the following structural block copolymers: S1-SP-S2;

[0009]

[0010] Among them, S1 and S2 are styrene homopolymer blocks; SP is a styrene and isoprene alternating copolymer block; and the hydrogenation rates of the benzene ring unit and the isoprene unit in the block copolymer are both greater than 99%.

[0011] The fully hydrogenated polystyrene-isopentadiene resin of the present invention has a special triblock structure, wherein the hydrogenated styrene block can provide mechanical strength through physical crosslinking, and the special alternating sequence of hydrogenated styrene and isoprene alternating copolymer blocks provides higher toughness and transparency, and the isoprene units and styrene units uniformly dispersed are fully saturated structures, which is beneficial to improving its chemical stability, increasing the glass transition temperature, being resistant to ultraviolet light and ozone, having good stability in high-temperature processing, and being able to realize direct injection molding.

[0012] As a preferred solution, the mass percentage of styrene units and isoprene units in the block copolymer is 70-90%:30-10%. If the isoprene unit ratio is too low, the volume of the middle block phase will be too small and the toughness will be seriously reduced. If the isoprene ratio is too high, the ratio of polystyrene segments at both ends will be too low, which will directly reduce the mechanical strength of the material.

[0013] As a preferred solution, the number average molecular weight of S1 and S2 is 30,000 to 60,000; the number average molecular weight of SP is 60,000 to 100,000. The molecular weight of the S1 and S2 blocks at both ends has a great influence on the performance of the entire polymer. Compared with SBS, the difference in solubility parameters between the intermediate SP alternating sequence block and the polystyrene block becomes smaller, resulting in a lower degree of phase separation. Therefore, the molecular weight of the S1 and S2 blocks must be larger, and the molecular weight of the intermediate SP segment needs to be controlled within an appropriate range to ensure the toughness of the entire polymer material.

[0014] The invention provides a method for preparing a transparent fully hydrogenated polystyrene-isopentadiene resin. The method comprises the following steps: firstly adding a styrene monomer and an initiator to perform homopolymerization I in an anionic polymerization solution system, then adding a styrene-isopentadiene mixed monomer to perform alternating copolymerization, then adding a styrene monomer to perform homopolymerization II or adding a coupling agent to perform coupling to obtain an S1-SP-S2 block copolymer; and the S1-SP-S2 block copolymer is obtained by performing a catalytic hydrogenation reaction using a loaded nickel catalyst.

[0015] As a preferred solution, the anionic polymerization solution system uses at least one of cyclopentane, cyclohexane, benzene and toluene as a solvent. The preferred solvent is cyclopentane and / or cyclohexane. The amount of solvent used is to ensure that the mass percentage concentration of the polymerization monomer in the solvent is about 15%.

[0016] As a preferred solution, the initiator is an organic lithium, preferably n-butyl lithium. The amount of the initiator is determined according to the actual designed polymer molecular weight, which is a well-known technology in the industry.

[0017] As a preferred solution, the temperature of the homopolymerization I is 25-80°C, and the time is 20-30 min. The temperature of the homopolymerization I is more preferably 50-70°C.

[0018] As a preferred solution, the temperature of the alternating copolymerization is 35-85°C and the time is 40-60 min. The temperature of the alternating copolymerization is further preferably 50-70°C. The present invention selects styrene and isoprene mixed monomers for copolymerization. Based on the electronic effect and steric effect of styrene and isoprene, under preferred temperature conditions, the copolymerization process between the two tends to alternating copolymerization, the alternating copolymerization rate reaches more than 90%, and isoprene mainly tends to 1,4 polymerization.

[0019] As a preferred solution, the temperature of the homopolymerization II is 50-70° C. and the time is 20-40 min.

[0020] As a preferred solution, the coupling temperature is 50-70°C and the time is 20-40 minutes. The coupling agent used in the coupling is preferably silicon dichloride, silicon tetrachloride, etc., and the amount of the coupling agent added is 1 / 3-1 / 4 of the molar amount of butyl lithium.

[0021] As a preferred solution, the temperature of the catalytic hydrogenation reaction is 160-260°C, the hydrogenation pressure is 5-9 MPa, and the time is 0.5-4 h. The temperature of the catalytic hydrogenation reaction is more preferably 200-240°C. The hydrogenation pressure is more preferably 6-8 MPa. The time is more preferably 0.5-4 h. Under the preferred hydrogenation reaction conditions, the degree of hydrogenation in the styrene unit and the pentadiene unit in the S1-SP-S2 block copolymer can be guaranteed to be greater than 99%.

[0022] As a preferred solution, the amount of the supported nickel hydrogenation catalyst used in the catalytic hydrogenation reaction is 3-20% of the mass of the S1-SP-S2 block copolymer. The nickel loading in the supported nickel hydrogenation catalyst is 50-65%, and the carrier is silicon dioxide or aluminum oxide. Further preferably, the amount of the supported nickel hydrogenation catalyst is 8-15% of the mass of the S1-SP-S2 block copolymer.

[0023] The invention provides a method for preparing a transparent fully hydrogenated polystyrene-isopentadiene resin, and the specific process is as follows: adding a hydrocarbon solvent and a styrene monomer into a polymerization kettle, and then adding an organic lithium initiator to carry out a first-stage polymerization, wherein the first-stage polymerization temperature is 50-70°C and the first-stage polymerization time is 20-30 minutes; adding a mixed monomer of styrene and isoprene to carry out a second-stage polymerization, wherein the second-stage polymerization temperature is controlled to be 50-70°C and the second-stage polymerization time is 40-60 minutes; after the second-stage polymerization is completed, styrene is added to carry out a third-stage polymerization, or a coupling agent is added to carry out a coupling reaction, and the reaction time is 20-40 minutes.

[0024] Then, the polymer is sent to a hydrogenation kettle, a supported nickel catalyst is added, and hydrogenation is carried out for 1 to 3 hours at a temperature of 200 to 240°C and a pressure of 6 to 8 MPa. After the hydrogenation is completed, the temperature is lowered, and when the temperature of the autoclave drops to room temperature, the hydrogen in the autoclave is discharged and the solution is released, and the catalyst is separated by centrifugation. Ethanol is added to the obtained clear liquid and stirred, and a white product is precipitated. Finally, it is placed in a 60°C oven for drying to obtain a hydrogenated product.

[0025] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0026] 1) The fully hydrogenated styrene-isopentadiene triblock copolymer provided by the present invention has a special molecular structure, wherein both ends are hydrogenated products of styrene homopolymer blocks, and the middle is a hydrogenated product of styrene and isopentadiene alternating copolymer blocks. The special molecular structure gives it good heat resistance, aging resistance, weather resistance, and ozone resistance, and has high toughness, transparency, good processability and film-forming properties, and is particularly suitable for the preparation of optical, electronic, transportation, remote sensing science and technology equipment, packaging materials and instrument panels.

[0027] 2) During the preparation process of the fully hydrogenated styrene-isopentadiene triblock copolymer of the present invention, a small amount of isoprene is introduced for alternating copolymerization with styrene, which effectively solves the problem of brittleness of styrene homopolymer. At the same time, its special molecular structure reduces the difficulty of hydrogenation, solves the problems of difficulty in hydrogenation of polystyrene, long hydrogenation time, and easy degradation of molecular chains. The hydrogenation rate of benzene rings in the fully hydrogenated polystyrene-isopentadiene resin is greater than 99%, and the hydrogenation rate of C=C in the isoprene unit is greater than 99%.

[0028] 3) The preparation process of the fully hydrogenated styrene-piperylene triblock copolymer of the present invention adopts a highly active supported nickel hydrogenation catalyst, which has low production cost, high hydrogenation efficiency and is easy for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a comparison chart of the HNMR spectra of the polystyrene-piperylene resin prepared in Example 1 before and after hydrogenation.

[0030] Figure 2 The HNMR spectra of the hydrogenated polystyrene-piperylene resins prepared in Examples 2, 3 and 4 are shown.

[0031] Figure 3 The HNMR spectra of the hydrogenated polystyrene-piperylene resins prepared in Comparative Example 1 and Comparative Example 2 are shown in FIG. DETAILED DESCRIPTION

[0032] The following is intended to further describe the contents of the specification of the present invention in detail in conjunction with specific embodiments, but the protection scope of the claims of the present invention is not limited thereto.

[0033] The resin samples were analyzed and characterized by nuclear magnetic resonance (H) spectrum, and the degree of hydrogenation was quantitatively calculated. The molecular weight (Mn) and molecular weight distribution (MWD) of the samples were analyzed and characterized by gel permeation chromatography, the physical properties of the samples were measured by INSTRON-5565 electronic tensile testing machine, and the transmittance of the samples was measured by DRTG-81 visible light transmittance meter.

[0034] Example 1

[0035] Add 3500mL of cyclohexane solution containing 10% n-hexane by mass to a 5L polymerization reactor. After the reactor is heated to 50°C, add 120mL of styrene and stir. Then add 6.5ml of 0.5mol / L n-butyl lithium to carry out first-stage polymerization for 30min. Then add 140mL of styrene and 123ml of isoprene mixed monomer to carry out second-stage copolymerization. Keep the temperature and polymerize for 60min. After the second-stage copolymerization is completed, add 120mL of styrene to carry out third-stage polymerization at 60°C for 25min. Add a small amount of methanol to terminate. The Mn of the polymer is 156000 and the MWD is 1.03.

[0036] Then, the polymer was pressed into a hydrogenation autoclave, 40 g of powdered supported nickel catalyst (SNCAT-6210P from Shanghai Xunkai New Materials Technology Co., Ltd.) was added, the hydrogen pressure was controlled to 7.0 MPa, the reaction was stirred at 220°C for 2 h, the temperature was lowered after the hydrogenation was completed, and the temperature of the autoclave was lowered to room temperature. The hydrogen in the autoclave was discharged and the solution was released, centrifuged, ethanol was added to the obtained clear liquid and stirred, a white product precipitated, and finally it was placed in an oven at 60°C to dry to obtain a hydrogenated product.

[0037] The hydrogenation rate of benzene rings in hydrogenated polystyrene-isopentadiene resin was 100%, and the hydrogenation rate of C=C in diene units was 100%. The resin was injection molded at 260°C, and its physical properties were measured, with a tensile strength of 52.7 MPa and a notched impact strength of 16.3 kJ / m 2 , light transmittance 92.8%.

[0038] Example 2

[0039] Add 3500mL of cyclohexane solution containing 10% n-hexane by mass to a 5L polymerization reactor. After the reactor is heated to 60°C, add 185mL of styrene and stir. Then add 8.3ml of 0.5mol / L n-butyl lithium to carry out first-stage polymerization for 25min. Then add 70mL of styrene and 62ml of isoprene mixed monomer to carry out second-stage copolymerization. Keep the temperature and polymerize for 40min. After the second-stage copolymerization is completed, add 164mL of styrene to carry out third-stage polymerization at 70°C for 30min. Add a small amount of methanol to terminate. The polymer Mn is 124300 and the MWD is 1.03.

[0040] Then, the polymer was pressed into a hydrogenation kettle, 60g of powdered nickel catalyst (SNCAT-6210P from Shanghai Xunkai New Materials Technology Co., Ltd.) was added, the hydrogen pressure was controlled to 6.0MPa, the reaction was stirred at 210°C for 1h, the temperature was lowered after the hydrogenation was completed, and the temperature of the autoclave was lowered to room temperature. The hydrogen in the autoclave was discharged and the solution was released, centrifuged, ethanol was added to the resulting clear liquid and stirred, a white product was precipitated, and finally it was placed in a 60°C oven to dry to obtain a hydrogenated product. The hydrogenation rate of the benzene ring in the hydrogenated polystyrene-isopentadiene resin was measured to be 100%, and the hydrogenation rate of C=C in the diene unit was 100%. The resin was injection molded and its physical properties were measured, with a tensile strength of 58.3MPa and a notched impact strength of 11.2kJ / m 2 , light transmittance 92.6%.

[0041] Example 3

[0042] Add 3500mL of cyclohexane solution containing 10% n-hexane by mass into a 5L polymerization reactor. After the reactor is heated to 65°C, add 120mL of styrene and stir. Then add 7.5ml of 0.5mol / L n-butyl lithium to carry out first-stage polymerization for 25min. Then add 140mL of styrene and 123ml of isoprene mixed monomer to carry out second-stage copolymerization. Keep the temperature for 40min. After the second-stage copolymerization is completed, add the calculated amount of silicon tetrachloride for coupling, where the molar ratio of [SiCl4] / [BuLi] is 0.38. Keep the temperature for coupling for 30min to obtain polymer glue. The polymer Mn is 272000 and the MWD is 1.13.

[0043] Then, the polymer was pressed into a hydrogenation kettle, 40g of powdered nickel catalyst (SNCAT-6210P from Shanghai Xunkai New Materials Technology Co., Ltd.) was added, the hydrogen pressure was controlled to 8.0MPa, and the reaction was stirred at 230-240°C for 2h. After the hydrogenation was completed, the temperature was lowered, and the temperature of the autoclave was lowered to room temperature. After the hydrogen in the autoclave was discharged, the solution was released and centrifuged. Ethanol was added to the resulting clear liquid and stirred. A white product was precipitated. Finally, it was placed in a 60°C oven to dry to obtain a hydrogenated product. The hydrogenation rate of the benzene ring in the hydrogenated polystyrene-isopentadiene resin was measured to be 100%, and the hydrogenation rate of C=C in the diene unit was 100%. The resin was injection molded and its physical properties were measured. The tensile strength was 53.8MPa and the notched impact strength was 14.7kJ / m 2 , light transmittance 92.3%.

[0044] Example 4

[0045] 3500mL of cyclopentane solution was added to a 5L polymerization reactor. After the reactor was heated to 55°C, 60mL of styrene was added and stirred. Then 6.5ml of 0.5mol / L n-butyl lithium was added to carry out first-stage polymerization for 20min. Then 210mL of styrene and 185ml of isoprene mixed monomer were added to carry out second-stage polymerization. The temperature was maintained for 60min. After the second-stage polymerization was completed, 60mL of styrene was added to carry out third-stage polymerization at 65°C for 25min and terminated by adding a small amount of methanol. The polymer Mn was 149000 and the MWD was 1.03.

[0046] Then, the polymer was pressed into a hydrogenation kettle, 34g of powdered nickel catalyst (SNCAT-6210P from Shanghai Xunkai New Materials Technology Co., Ltd.) was added, the hydrogen pressure was controlled to 7.5MPa, the reaction was stirred at 220°C for 3h, the temperature was lowered after the hydrogenation was completed, and the temperature of the autoclave was lowered to room temperature. The hydrogen in the autoclave was discharged and the solution was released, centrifuged, ethanol was added to the resulting clear liquid and stirred, a white product was precipitated, and finally it was placed in a 60°C oven to dry to obtain a hydrogenated product. The hydrogenation rate of the benzene ring in the hydrogenated polystyrene-isopentadiene resin was measured to be 99.7%, and the C=C hydrogenation rate in the diene unit was 100%. The resin was injection molded, and its physical properties were measured, with a tensile strength of 48.6MPa and a notched impact strength of 18.5kJ / m 2 , light transmittance 91.8%.

[0047] Comparative Example 1

[0048] 3500mL of cyclopentane solution was added to a 5L polymerization reactor. After the reactor was heated to 50°C, 120mL of styrene was added and stirred. Then 3.0ml of 1.0mol / L structure regulator ditetrahydrofuran propane and 6.5ml of 0.5mol / L n-butyl lithium were added to carry out first-stage polymerization for 20min. Then 140mL of styrene and 125ml of isoprene mixed monomer were added to carry out second-stage polymerization. The second-stage mixed monomer was fed in 5 times, 53ml each time, with an interval of 10min between each feeding, and the temperature was maintained for polymerization for 40min. After the second-stage polymerization was completed, 120mL of styrene was added to carry out third-stage polymerization for 25min, and a small amount of methanol was added to terminate. The polymer Mn was 165000 and the MWD was 1.04.

[0049] Then, the polymer was pressed into a hydrogenation kettle, 40g of powdered nickel catalyst (SNCAT-6210P from Shanghai Xunkai New Materials Technology Co., Ltd.) was added, the hydrogen pressure was controlled to 8MPa, and the reaction was stirred at 210-230°C for 6h. After the hydrogenation was completed, the temperature was lowered until the temperature of the autoclave dropped to room temperature, the hydrogen in the autoclave was discharged, the solution was released, centrifuged, ethanol was added to the resulting clear liquid and stirred, a white product precipitated, and finally it was placed in a 60°C oven to dry to obtain a hydrogenated product. The hydrogenation rate of the benzene ring in the hydrogenated resin was measured to be 99.5%, and the C=C hydrogenation rate in the isoprene unit was 100%. The resin was injection molded, and its physical properties were measured, with a tensile strength of 32.6MPa and a notched impact strength of 2.5kJ / m 2 , light transmittance 85.8%.

[0050] Comparative Example 2

[0051] 3500mL of cyclopentane solution was added to a 5L polymerization reactor. After the reactor was heated to 50°C, 120mL of styrene was added and stirred. Then 3.0ml of 1.0mol / L structure regulator ditetrahydrofuran propane and 6.5ml of 0.5mol / L n-butyl lithium were added to carry out first-stage polymerization for 20min. Then 140mL of styrene and 110ml of butadiene mixed monomer were added to carry out second-stage polymerization. The second-stage mixed monomer was fed in 5 times, 50ml each time, with an interval of 10min between each feeding, and the temperature was maintained for polymerization for 60min. After the second-stage polymerization was completed, 120mL of styrene was added to carry out third-stage polymerization at 60°C for 25min, and a small amount of methanol was added to terminate. The polymer Mn was 167000 and the MWD was 1.04.

[0052] Then, the polymer was pressed into a hydrogenation kettle, 40g of powdered nickel catalyst (SNCAT-6210P from Shanghai Xunkai New Materials Technology Co., Ltd.) was added, the hydrogen pressure was controlled to 8MPa, the reaction was stirred at 220°C for 7h, the temperature was lowered after the hydrogenation was completed, and the temperature of the autoclave was lowered to room temperature. The hydrogen in the autoclave was discharged and the solution was released, centrifuged, ethanol was added to the resulting clear liquid and stirred, a white product was precipitated, and finally it was placed in a 60°C oven to dry to obtain a hydrogenated product. The hydrogenation rate of the benzene ring in the hydrogenated resin was measured to be 99.2%, and the C=C hydrogenation rate in the butadiene unit was 100%. The resin was injection molded, and its physical properties were measured, with a tensile strength of 42.1MPa and a notched impact strength of 4.6kJ / m 2 , light transmittance 87.8%.

Claims

1. A transparent fully hydrogenated polystyrene-piperylene resin, characterized in that: Obtained by complete hydrogenation of the following structural block copolymers: S1-SP-S2; in, S1 and S2 are styrene homoblocks; SP is an alternating copolymer block of styrene and isoprene; The hydrogenation rates of the benzene ring units and the isopentylene units in the block copolymer are both greater than 99%.

2. A transparent fully hydrogenated polystyrene-piperylene resin according to claim 1, characterized in that: The mass percentage composition of the styrene unit and the isoprene unit in the block copolymer is 70-90%:30-10%.

3. A transparent fully hydrogenated polystyrene-piperylene resin according to claim 1 or 2, characterized in that: The number average molecular weight of S1 and S2 is 30,000 to 60,000; The number average molecular weight of SP is between 60,000 and 100,000.

4. A method for preparing a transparent fully hydrogenated polystyrene-piperylene resin according to any one of claims 1 to 3, characterized in that: In an anionic polymerization solution system, styrene monomer and initiator are first added for homopolymerization I, then styrene-isopentadiene mixed monomer is added for alternating copolymerization, and then styrene monomer is added for homopolymerization II or a coupling agent is added for coupling to obtain S1-SP-S2 block copolymer; the S1-SP-S2 block copolymer is obtained by catalytic hydrogenation reaction using a supported nickel catalyst.

5. The method for preparing a transparent fully hydrogenated polystyrene-piperylene resin according to claim 4, characterized in that: The anionic polymerization solution system uses at least one of cyclopentane, cyclohexane, benzene and toluene as a solvent.

6. The method for preparing a transparent fully hydrogenated polystyrene-piperylene resin according to claim 4, characterized in that: The initiator is organic lithium.

7. A method for preparing a transparent fully hydrogenated polystyrene-piperylene resin according to claim 4, 5 or 6, characterized in that: The temperature of the homopolymerization I is 25-80° C. and the time is 20-30 min.

8. A method for preparing a transparent fully hydrogenated polystyrene-piperylene resin according to claim 4, 5 or 6, characterized in that: The temperature of the alternating copolymerization is 35-85° C., and the time is 40-60 min.

9. A method for preparing a transparent fully hydrogenated polystyrene-piperylene resin according to claim 4, 5 or 6, characterized in that: The temperature of the homopolymerization II is 50-70° C. and the time is 20-40 min.

10. A method for preparing a transparent fully hydrogenated polystyrene-piperylene resin according to claim 4, 5 or 6, characterized in that: The coupling temperature is 50-70° C. and the coupling time is 20-40 min.

11. A method for preparing a transparent fully hydrogenated polystyrene-piperylene resin according to claim 4, 5 or 6, characterized in that: The temperature of the catalytic hydrogenation reaction is 160-260° C., the hydrogenation pressure is 5-9 MPa, and the time is 0.5-4 h.

12. The method for preparing a transparent fully hydrogenated polystyrene-piperylene resin according to claim 11, characterized in that: The amount of the supported nickel hydrogenation catalyst used in the catalytic hydrogenation reaction is 3-20% of the mass of the S1-SP-S2 block copolymer.

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