CN112409557B - Vegetable oil-based polyurethane film and preparation thereof - Google Patents

Abstract

A vegetable oil-based polyurethane film and its preparation are provided. The preparation method comprises the following steps: preparing hydroxylated epoxidized soybean oil from epoxidized soybean oil, polyethylene glycol and concentrated sulfuric acid; according to a certain proportion, diisocyanate and hydroxylated epoxidized soybean oil are added with a catalyst, heated by using an oil bath, vegetable oil-based polyurethane is prepared under the atmosphere of nitrogen protection, and a polytetrafluoroethylene plate is used for tape casting and film forming. The polyurethane film has good hydrophobicity, toughness and ductility, and meanwhile, the vegetable oil-based raw material is used for overcoming the difficulties of difficult degradation of materials and the like.

Description

A kind of vegetable oil-based polyurethane film and its preparation

technical field

The invention relates to the field of polymer materials, in particular to a vegetable oil-based polyurethane film and a preparation method thereof.

Background technique

With the increasing application of polymer films in the packaging field, the requirements for film performance are becoming more and more stringent. Compared with other films with single properties, polyurethane has good comprehensive properties. Polyurethane is an emerging organic polymer material. Polyurethane is even known as the "fifth largest plastic" in the field of polymer materials. It is widely used in many fields of the national economy because of its excellent performance. The product application fields involve light industry, chemical industry, electronics, textile, medical treatment, construction, building materials, automobile, national defense, aerospace, aviation and so on. Polyurethane products are also on the rise in China. Compared with other polymer films, polyurethane film has excellent tension, tension, toughness, aging resistance, wear resistance and impact resistance. The processing technology is simple and the cost can be reduced. Polyurethanes are usually synthesized by polyaddition polymerization of polyols and diisocyanates. The hydroxyl-terminated polyesters and hydroxyl-terminated polyethers of traditional synthetic polyurethanes mainly come from petrochemical resource routes, and petrochemical resources are easily in short supply. Therefore, the use of bio-based polyols to replace polyester and polyether polyols has become a research hotspot.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art and provide a novel polyurethane film with high performance and beautiful appearance. Through comparative research on existing polyurethane synthetic materials, a vegetable oil-based polyurethane film with good mechanical properties, exquisite appearance and good hydrophobicity is prepared, and a method for preparing the film is provided at the same time.

The object of the present invention is achieved through the following solutions:

A kind of vegetable oil base polyurethane film, comprises the following steps:

(1) The preparation of hydroxylated epoxy vegetable oil: adopt the 250ml round bottom three-neck flask that connects mechanical stirrer, condenser, nitrogen inlet and outlet respectively as hydroxylation reaction container, mix polyethylene glycol, epoxy vegetable oil in a certain proportion , the catalyst is added to the reaction, and the whole reaction process is heated in an oil bath;

(2) Preparation of vegetable oil-based polyurethane film: Add hydroxylated epoxy vegetable oil, diisocyanate, and catalyst to the reactor in a certain proportion, react in an oil bath at 70-90°C for 15-30min, pour it into a beaker, add The organic solvent is dissolved, the dissolved solution is poured on a tetrafluoroethylene plate, and the solvent is dried in an oven at 30-70° C. to obtain a vegetable oil-based polyurethane film.

Step (1) After heating, add an appropriate amount of sodium carbonate solution to terminate the reaction, and also include a separation and purification step. The separation and purification step is: cooling the mixture to room temperature, extracting unreacted polyethylene glycol with deionized water, After liquid separation, the organic layer was dried to remove water, and then subjected to rotary evaporation to obtain a light yellow viscous liquid hydroxylated epoxy vegetable oil.

In step (1), heat to 100-120° C., and the reaction time is 2-3 hours.

The epoxidized vegetable oil described in step (1) is epoxidized soybean oil.

The polyethylene glycol in step (1) is one of polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol 600.

The molar ratio of polyethylene glycol and epoxy vegetable oil in step (1) is 1.6:1-3:1.

The catalyst in the step (1) is concentrated sulfuric acid, and its consumption is 0.3-0.5% of the total weight of the hydroxylated epoxy vegetable oil.

The diisocyanate in the step (2) is isophorone diisocyanate, and its dosage is 30-39.16% of the total mass of the film-forming substances.

The amount of the hydroxylated epoxy vegetable oil in step (2) is 60.68-69.83% of the total mass of the film-forming substance.

In the step (2), the catalyst is dibutyltin dilaurate, and the amount thereof is 0.13-0.17% of the total mass of the film-forming substance.

The organic solvent described in step (2) is N,N-dimethylformamide, and an appropriate amount of organic solvent can be added when the viscosity is too high during the reaction process.

The reaction process described in step (1) and step (2) must be carried out under nitrogen atmosphere.

Advantage and positive effect of the present invention are:

(1) Open up a new application field for natural materials, improve their use value, and on the other hand, greatly ease the pressure of petrochemical industry.

(2) The polyurethane film prepared by the present invention has good aesthetics.

(3) The polyurethane film prepared by the present invention has good hydrophobicity.

(4) The polyurethane film prepared by the present invention has good toughness and ductility.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and through specific embodiments. The following embodiments are only descriptive, not restrictive, and cannot limit the protection scope of the present invention.

Example 1

In this embodiment, we take the formula in table 1 to carry out experimental research:

Table 1 Vegetable oil-based polyurethane film formulation

(1) Preparation of hydroxylated epoxy vegetable oil: adopt the 250ml round-bottomed three-necked flask that is respectively connected to mechanical stirrer, condenser, nitrogen inlet and outlet as hydroxylation reaction vessel, press the mole of polyethylene glycol 600 and epoxy soybean oil The ratio is 1.66:1, the amount of concentrated sulfuric acid is 0.5% of the total weight of the hydroxylated epoxy vegetable oil, and the reaction is added to the reaction. The whole reaction process is heated in an oil bath at 100° C. for 3 hours, and then 10 ml of 0.1 mol/l sodium carbonate solution is added to terminate the reaction. reaction, cooling the mixture to room temperature, extracting the unreacted polyethylene glycol with deionized water, separating the liquids, drying the organic layer to remove water, and performing rotary evaporation to obtain a light yellow viscous liquid hydroxylated epoxy vegetable oil .

(2) Preparation of vegetable oil-based polyurethane film: Add hydroxylated epoxy vegetable oil, isophorone diisocyanate, and dibutyltin dilaurate to the reactor according to the formula in Table 1, and react in an oil bath at 80°C. When a large number of bubbles appear 5ml of N,N-dimethylformamide was added at this time.

(3) Film formation

Pour the polyurethane prepolymer into a beaker, pour N,N-dimethylformamide, under magnetic stirring, the solvent dissolves the prepolymer at 40°C, and pour the dissolved product into a polytetrafluoroethylene plate , and put it into a 50°C oven to dry to form a film.

(4) Performance test

①Mechanical properties

Samples were prepared according to the ASTM D-882 test standard, and the tensile strength and elongation at break of the film were tested. The test results are shown in Table 6.

②Water contact angle

Samples were prepared according to the GB/T30693-2014 test standard, and the water contact angle of the film was tested. The test results are shown in Table 6.

Example 2

In this embodiment, we take the formula in table 2 to carry out experimental research:

Table 2 Vegetable oil-based polyurethane film formulation

Other steps are the same as in Embodiment 1.

Performance Testing

①Mechanical properties

Samples were prepared according to the ASTM D-882 test standard, and the tensile strength and elongation at break of the film were tested. The test results are shown in Table 6.

②Water contact angle

Samples were prepared according to the GB/T30693-2014 test standard, and the water contact angle of the film was tested. The test results are shown in Table 6.

Example 3

In this embodiment, we take the formula in table 3 to carry out experimental research:

Table 3 Vegetable oil-based polyurethane film formulation

Other steps are identical with specific embodiment 1 to 2.

Performance Testing

①Mechanical properties

Samples were prepared according to the ASTM D-882 test standard, and the tensile strength and elongation at break of the film were tested. The test results are shown in Table 6.

②Water contact angle

Samples were prepared according to the GB/T30693-2014 test standard, and the water contact angle of the film was tested. The test results are shown in Table 6.

Example 4

In this embodiment, we take the formula in table 4 to carry out experimental research:

Table 4 Vegetable oil-based polyurethane film formula

Other steps are identical with specific embodiment 1 to 3.

Performance Testing

①Mechanical properties

Samples were prepared according to the ASTM D-882 test standard, and the tensile strength and elongation at break of the film were tested. The test results are shown in Table 6.

②Water contact angle

Samples were prepared according to the GB/T30693-2014 test standard, and the water contact angle of the film was tested. The test results are shown in Table 6.

Example 5

In this embodiment, we take the formula in table 5 to carry out experimental research:

Table 5 Vegetable oil-based polyurethane film formulation

Other steps are identical with specific embodiment 1 to 4.

Performance Testing

①Mechanical properties

Samples were prepared according to the ASTM D-882 test standard, and the tensile strength and elongation at break of the film were tested. The test results are shown in Table 6.

②Water contact angle

Samples were prepared according to the GB/T30693-2014 test standard, and the water contact angle of the film was tested. The test results are shown in Table 6.

Table 6 example one to five gained finished product test results

The above are only preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, some modifications and improvements can be made without departing from the inventive concept, and these all belong to the scope of the present invention. protected range.

Description of drawings

Fig. 1 is the flowchart of the method of the present invention.

Claims (2)

1. The preparation method of the vegetable oil-based polyurethane film is characterized by comprising the following steps of:

(1) Preparation of hydroxylated epoxy vegetable oil: a 250ml round bottom three-neck flask which is respectively connected with a mechanical stirrer, a condenser and a nitrogen inlet and outlet is adopted as a hydroxylation reaction vessel, polyethylene glycol, epoxy vegetable oil and a catalyst are added for reaction, and the whole reaction process is heated to 100-120 ℃ in an oil bath, and the reaction time is 2-3 h; the mol ratio of the polyethylene glycol to the epoxy vegetable oil is 1.6:1-3:1;

the catalyst in the step (1) is concentrated sulfuric acid, and the dosage of the catalyst is 0.3-0.5% of the total weight of the hydroxylated epoxidized vegetable oil reaction;

the epoxidized vegetable oil in the step (1) is epoxidized soybean oil;

the polyethylene glycol in the step (1) is polyethylene glycol 600;

(2) Preparing a vegetable oil-based polyurethane film: adding hydroxylated epoxy vegetable oil, diisocyanate and a catalyst into a reactor, reacting for 15-30min in an oil bath at 70-90 ℃, pouring into a beaker, adding an organic solvent for dissolution, pouring the dissolved solution onto a tetrafluoroethylene plate, and placing into a baking oven at 30-70 ℃ to dry the solvent, thus obtaining the vegetable oil-based polyurethane film; the total mass of the film forming material is 64.05%, the total mass of the film forming material is 35.81% and the total mass of the film forming material is 35.14% respectively, the total mass of the film forming material is 62.32%, the total mass of the film forming material is 37.53%, the total mass of the film forming material is 0.15%, the total mass of the film forming material is 60.70%, the total mass of the film forming material is 39.16%, and the total mass of the film forming material is 0.14%;

the diisocyanate in the step (2) is isophorone diisocyanate;

the catalyst in the step (2) is dibutyl tin dilaurate; the organic solvent in the step (2) is N, N-dimethylformamide, and a proper amount of organic solvent can be added when the viscosity is excessive in the reaction process; the reaction process in the step (1) and the step (2) must be carried out under a nitrogen atmosphere.

2. The vegetable oil-based polyurethane film of claim 1, wherein the reaction is terminated by adding an appropriate amount of sodium carbonate solution after heating in step (1), and further comprising a separation and purification step.

Images