CN118459717A - A kind of polybutadiene polyurethane acrylate photosensitive resin and preparation method thereof - Google Patents

Abstract

The invention discloses a polybutadiene polyurethane acrylate photosensitive resin and a preparation method thereof. On a molar basis, terminal hydroxyl polybutadiene is reacted with diisocyanate, and finally a measured amount of hydroxyl-containing acrylic monomer is added dropwise for grafting reaction to obtain a polybutadiene polyurethane acrylate photosensitive resin containing a photosensitive methacrylic acid group. The polybutadiene polyurethane acrylate provided by the invention retains the excellent low-temperature resistance and toughness of polybutadiene, and the introduction of the photosensitive methacrylic acid group enables it to be cured by ultraviolet light irradiation, providing a new solution for the molding of polybutadiene, and can be used for the preparation of photosensitive resins for photocurable flexible materials, the use of coating materials and adhesives, etc., and has the advantages of high production efficiency, low pollution, and energy saving.

Description

A kind of polybutadiene polyurethane acrylate photosensitive resin and preparation method thereof

Technical Field

The invention relates to the technical field of ultraviolet curing materials, and in particular provides a polybutadiene polyurethane acrylate photosensitive resin and a preparation method thereof.

Background Art

The main chain of the hydroxy-terminated polybutadiene (HTPB) structure is mainly composed of a large number of unsaturated double bonds. It is a high molecular weight substance containing hydroxyl groups at both ends of the molecular chain. The molecular weight distribution is relatively wide, ranging from 1500 to 10000. It is a kind of telechelic polymer with the advantages of low glass transition temperature, good transparency, low viscosity, oil resistance, low temperature resistance, good processability, etc. It can be used with chain extenders, curing agents, etc. to generate polyurethane elastomers with a network structure at a certain temperature. The elastomer has excellent mechanical properties, good oil resistance, acid and alkali resistance, and water resistance. It is widely used in both military and civilian fields. It can be mainly used in structural materials for automobile and aircraft tires, building materials, rubber products for shoe materials, thermal insulation materials, coating adhesives, etc.

However, the main chain of terminal hydroxyl polybutadiene is a non-polar chain, which is difficult to dissolve with existing 3D printing photosensitive resins. In addition, the low-temperature performance of existing polybutadiene used for UV-curing 3D printed products is generally poor. Therefore, it is necessary to solve its compatibility and low-temperature resistance, and use polybutadiene in UV-curing technology to broaden its application range.

In view of the shortcomings of the existing HTPB resin preparation method, the development of a terminal hydroxyl polybutadiene polyurethane acrylate with excellent performance and simple synthesis process will have important application value and academic significance.

Summary of the invention

In view of the situation and shortcomings of the prior art, the purpose of the present invention is to provide a polybutadiene polyurethane acrylate photosensitive resin and a preparation method thereof. By grafting -NCO groups on both ends of the terminal hydroxyl polybutadiene and then grafting methacrylic acid structures, the low-temperature toughness of the terminal hydroxyl polybutadiene is improved, and ultraviolet light curing can be performed at the same time, solving the disadvantage of poor compatibility of the terminal hydroxyl polybutadiene with other resins.

In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

A method for preparing a polybutadiene polyurethane acrylate photosensitive resin comprises the following steps:

(1) Mix 100 parts of hydroxy-terminated polybutadiene and 200 parts of diisocyanate by mole, then add an appropriate amount of solvent and 0.1 to 2 parts of catalyst, and react at 60 to 100° C. for 1 to 3 hours under N ₂ protection to obtain prepolymer A;

(2) Add 200 parts by mole of hydroxyl-containing acrylic monomer to prepolymer A, react at 50-90° C. for 1-3 hours, and remove the solvent in vacuo to obtain a polybutadiene polyurethane acrylate photosensitive resin.

The structural formula of the polybutadiene polyurethane acrylate photosensitive resin is as follows:

Wherein, x is 27 to 65;

The structural formula of _R1 is any of the following:

The structural formula of _R2 is any of the following:

Furthermore, the polybutadiene is one or a combination of 1,2 addition polybutadiene, trans 1,4 addition polybutadiene, cis 1,4 addition polybutadiene.

Furthermore, the diisocyanate is one or a combination of toluene diisocyanate (TDI), hexamethylene diisocyanate (HMDI), 4,4′-diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate, isophorone diisocyanate (IPDI), triphenylmethane triisocyanate, xylene diisocyanate, 1,4-cyclohexylene diisocyanate, and 1,4-tetrahydronaphthylene diisocyanate.

Furthermore, the solvent is one or a combination of more than one of ethyl acetate, acetone and tetrahydrofuran.

Furthermore, the catalyst is one or a combination of stannous octoate, tin butyrate, dibutyltin diacetate, dibutyltin dioctoate, chelated tin, dibutyltin dilaurate, and trialkylamine.

Furthermore, the hydroxyl-containing acrylic monomer is one or a combination of more than one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, pentaerythritol triacrylate and dipentaerythritol pentaacrylate.

The technical idea of the present invention is to copolymerize terminal hydroxyl polybutadiene containing a large number of unsaturated double bonds with diisocyanate with NCO groups, and combine the excellent properties of polyurethane and terminal hydroxyl polybutadiene. Terminal hydroxyl polybutadiene has excellent low-temperature resistance, so it can be used as a toughening modifier for making hard resins, and can also improve the low-temperature resistance and mechanical strength of the resin. The excellent properties of the resin are reflected by using methacrylic acid double bond photosensitive groups for end-capping through ultraviolet curing.

Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the raw material source of the polybutadiene polyurethane acrylate photosensitive resin provided by the present invention is wide, the price is low, and the synthesis process is simple, which is suitable for large-scale production and application. Polybutadiene reacts with diisocyanate, and there are a large number of carbamate groups, which retains the excellent properties of polyurethane in structure, and integrates the low-temperature toughness of terminal hydroxyl polybutadiene, effectively enhancing the low-temperature toughness of the material, improving the fracture strength and rebound rate, and having good mechanical properties. At the same time, the methyl acrylate structure of the grafted photosensitive group can be cured by ultraviolet light irradiation, and has the advantages of fast curing speed, high production efficiency, low pollution, and energy saving.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a general synthesis formula of the hydroxy-terminated polybutadiene polyurethane acrylate photosensitive resin of the present invention.

FIG. 2 is an infrared spectrum of the polybutadiene polyurethane acrylate photosensitive resin prepared in Example 1 of the present invention.

FIG. 3 is a nuclear magnetic hydrogen spectrum ( ¹ H-NMR) of the polybutadiene polyurethane acrylate photosensitive resin prepared in Example 1 of the present invention.

DETAILED DESCRIPTION

Example 1

(1) Using ethyl acetate as solvent, 0.0105 mol of hydroxy-terminated polybutadiene (hydroxyl value: 0.7 mmol/g) (HTPB) and 0.021 mol of toluene diisocyanate (TDI) were added, and then 0.0010 mol of dibutyltin dilaurate was added as a catalyst, and the mixture was reacted at 85° C. for 2 hours under N ₂ protection to obtain an intermediate prepolymer A;

(2) 0.021 mol of hydroxyethyl methacrylate (HEMA) was added to prepolymer A and reacted at 75° C. for 2 hours to obtain prepolymer B. After vacuum removal of the solvent, polybutadiene polyurethane acrylate was obtained, and the structure was as follows:

See Figure 2, which is the infrared (FTIR) spectrum of the hydroxy-terminated polybutadiene polyurethane acrylate photosensitive resin prepared in Example 1 of the present invention. It can be seen from the curve graph that the characteristic absorption peak of the NCO group at 2200-2250cm ^-1 disappears from the infrared spectrum of the product, which indicates that the NCO in TDI has completely reacted with the OH in HTPB and the OH in HEMA. Secondly, it can be seen that the vibration absorption peaks of -NHCOO-, C＝C, and CN at 1722cm ^-1 , 1673cm ^-1 , and 1223cm ^-1 also show the reaction of NCO with OH, and the successful incorporation of the double bond of acrylic acid into the product, and the product is successfully synthesized.

See Figure 3, which is the nuclear magnetic hydrogen spectrum ( ^1H -NMR) of the hydroxy-terminated polybutadiene polyurethane acrylate photosensitive resin prepared in Example 1 of the present invention, further verifying that the structure δ values at 6.71, 6.97, and 7.1ppm correspond to the hydrogen protons on the TDI benzene ring, and δ at 2.29ppm corresponds to the hydrogen protons on the methyl group on the TDI benzene ring. The hydrogen protons on the imino group on the carbamate are located at 7.75ppm, and 4.6-5.9ppm are the hydrogen proton signals on the olefin. This shows that toluene diisocyanate reacts with HTPB to form carbamate groups, and analysis shows that the product synthesis is consistent with expectations.

Example 2

(1) Using ethyl acetate as solvent, 0.0105 mol of hydroxy-terminated polybutadiene (hydroxyl value: 0.7 mmol/g) (HTPB) and 0.021 mol of p-phenylene diisocyanate (PPDI) were added, and then 0.0010 mol of dibutyltin dilaurate was added as a catalyst, and the mixture was reacted at 85° C. for 2 hours under N ₂ protection to obtain an intermediate prepolymer A;

(2) 0.021 mol of hydroxyethyl methacrylate (HEMA) was added to prepolymer A and reacted at 75° C. for 2 hours to obtain prepolymer B. After vacuum removal of the solvent, polybutadiene polyurethane acrylate was obtained, and the structure was as follows:

Example 3

(1) Using tetrahydrofuran as solvent, adding 0.0105 mol of hydroxy-terminated polybutadiene (hydroxyl value: 0.7 mmol/g) (HTPB) and 0.021 mol of toluene diisocyanate (PPDI), and then adding 0.0010 mol of dibutyltin dilaurate as a catalyst, reacting at 85° C. for 2 hours under N ₂ protection to obtain an intermediate prepolymer A;

(2) 0.021 mol of hydroxyethyl methacrylate (HEMA) was added to prepolymer A and reacted at 75° C. for 2 hours to obtain prepolymer B. After vacuum removal of the solvent, polybutadiene polyurethane acrylate was obtained, and the structure was as follows:

Claims (8)

1. The preparation method of the polybutadiene polyurethane acrylate photosensitive resin is characterized by comprising the following steps of:

(1) Mixing 100 parts of hydroxyl-terminated polybutadiene and 200 parts of diisocyanate according to mole, adding a solvent and 0.1-2 parts of catalyst, and reacting for 1-3 hours at 60-100 ℃ under the protection of N ₂ to obtain a prepolymer A;

(2) Adding 200 parts of hydroxyl-containing acrylic acid monomer into the prepolymer A according to the mole, reacting for 1-3 hours at 50-90 ℃, and vacuum pumping the solvent to obtain the polybutadiene polyurethane acrylate photosensitive resin.

2. The method for preparing the polybutadiene polyurethane acrylate photosensitive resin according to claim 1, wherein the polybutadiene polyurethane acrylate photosensitive resin has the following structural formula:

Wherein x is 27-65;

r ₁ has the structural formula as follows:

R ₂ has the structural formula as follows:

3. The method for preparing the polybutadiene polyurethane acrylate photosensitive resin according to claim 1, wherein the polybutadiene is one or a combination of more than one of 1, 2-addition polybutadiene, trans-1, 4-addition polybutadiene and cis-1, 4-addition polybutadiene.

4. The method for preparing polybutadiene polyurethane acrylate photosensitive resin according to claim 1, wherein the diisocyanate is one or more of toluene diisocyanate, hexamethylene diisocyanate, 4' -diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, isophorone diisocyanate, triphenylmethane triisocyanate, xylene diisocyanate, 1, 4-cyclo-hexamethylene diisocyanate and 1, 4-tetrahydronaphthalene diisocyanate.

5. The method for preparing polybutadiene polyurethane acrylate photosensitive resin according to claim 1, wherein the solvent is one or more of ethyl acetate, acetone and tetrahydrofuran.

6. The method for preparing polybutadiene polyurethane acrylate photosensitive resin according to claim 1, wherein the catalyst is one or a combination of stannous octoate, tin butyrate, dibutyltin diacetate, dibutyltin dioctoate, chelated tin, dibutyltin dilaurate and trialkylamine.

7. The method for preparing the polybutadiene polyurethane acrylate photosensitive resin according to claim 1, which is characterized in that: the hydroxyl-containing acrylic monomer is one or a combination of more than one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, pentaerythritol triacrylate and dipentaerythritol pentaacrylate.

8. A polybutadiene urethane acrylate photosensitive resin obtained by the production process according to any one of claims 1 to 7.