CN107383335B - A kind of method for preparing polyisoprene supramolecular elastomer - Google Patents

Abstract

The present invention relates to a kind of methods for preparing polyisoprene supermolecule elastomer, the polyisoprene supermolecule elastomer for increasing hydroxyl group sites quantity is prepared in four steps such as the preparation of preparation, epoxidized polyisoprene including polyisoprene, the preparation of grafted methacrylic acid epoxy polyisoprene, the preparation of polyisoprene elastomer.Compared with prior art, the present invention is capable of forming more Quadrupolar hydrogen bonds, promotes the effect of hydrogen bond action, improves damping.

Description

A kind of method for preparing polyisoprene supramolecular elastomer

technical field

The invention relates to a method for preparing an elastomer, in particular to a method for preparing a polyisoprene supramolecular elastomer.

Background technique

With the development of modern industry, vibrating tools and high-power machines that generate strong vibrations are increasing, and the vibration hazards caused by various mechanical equipment during operation and work are becoming more and more serious. In daily life, it has a great impact on people's life and work. In engineering, it directly affects the normal operation of electronic devices, instruments and meters, and in severe cases, it will cause disastrous consequences. Using high damping materials or damping structures to reduce vibration and noise has become one of the most effective means to solve the above problems.

Damping material is a functional material that can absorb vibrational mechanical energy and convert it into heat energy for dissipation. Polymer damping materials have the characteristics of wide damping temperature range and high damping factor. The commonly used methods to improve the damping performance mainly include two types: one is to change the macromolecular structure of the polymer. Change the rigid structure of the molecular chain by grafting, block and other methods, and adjust the different ratios of rigid chains and flexible chains on the main chain and side chains; the second is the interpenetrating polymer network (IPN) technology, which can interpenetrate through the network And the chain winding effect can effectively control the compatibility between the polymer blend components and broaden the damping temperature range.

The reason why hydrogen-bonded supramolecular elastomers are used as damping materials to achieve the effect of damping and vibration reduction is that hydrogen bond structures can be formed between polymer molecular chains, especially between supramolecular polymers modified by UPy groups. Quadruple hydrogen bonds enhance the intermolecular force, increase the mechanical strength, and improve the damping performance. Wu Jiaming and others invented a method for room temperature vulcanization of polyisoprene rubber (Wu Jiaming, Wang Jincheng, Zhao Wen, Cao Fuhai, Zhang Guangjian, Yuan Zhanglin, A preparation method of room temperature vulcanization polyisoprene rubber, ZL201410453519.5) , in this technology, the hydroxyl sites are only distributed at one end, so the number of quadruple hydrogen bonds formed later is not enough. Therefore, it is necessary to increase the number of hydroxyl sites, thereby forming more quadruple hydrogen bonds, and improving the efficiency of hydrogen bonding. effect, thereby improving the damping effect.

Contents of the invention

The purpose of the present invention is to provide a method for preparing a polyisoprene supramolecular elastomer that increases the number of hydroxyl sites in order to overcome the above-mentioned defects in the prior art, thereby forming more quadruple hydrogen bonds and improving hydrogen bond effect, improve the damping effect.

The purpose of the present invention can be achieved through the following technical solutions:

A method for preparing polyisoprene supramolecular elastomer, adopts the following steps:

(1) Preparation of polyisoprene

Under a nitrogen atmosphere, mix isoprene and sec-butyllithium, control the temperature at 0-20°C and react for 4-6 hours, then inject degassed methanol to terminate, pour into isopropanol to precipitate, and obtain white viscous Polyisoprene;

(2) Preparation of epoxidized polyisoprene

Put polyisoprene and m-chloroperoxybenzoic acid in dichloromethane, control the temperature below zero to react for 4-6h, filter the unreacted m-chloroperoxybenzoic acid filtrate with saturated sodium bicarbonate solution and Washing with sodium chloride solution three times, separating the organic phase and drying with anhydrous magnesium sulfate, and obtaining epoxidized polyisoprene after removing methylene chloride;

(3) Preparation of grafted methacrylic acid epoxy polyisoprene

Dissolve epoxy polyisoprene in toluene, reflux at 100°C for 24 hours after adding methacrylic acid dropwise, and spin-evaporate grafted methacrylic acid epoxy polyisoprene after the reaction is completed;

(4) Preparation of polyisoprene elastomer

Stir the grafted methacrylic acid epoxidized polyisoprene and hexamethylene diisocyanate under nitrogen atmosphere and room temperature for 3-5h to generate epoxidized polyisoprene with NCO terminal group, then add 6 - Methylisocytosine, after stirring for 30-50 minutes under a nitrogen atmosphere at room temperature, the temperature is raised to 20-40° C. and kept for 3-5 hours to obtain a polyisoprene supramolecular elastomer containing UPy groups.

The volume ratio of isoprene, sec-butyllithium, methanol, and isopropanol described in step (1) is 30-50:0.3-0.5:3-5:10-20, and the reaction temperature is preferably 5-10 ℃.

The ratio of polyisoprene, m-chloroperbenzoic acid and methylene chloride described in step (2) is 20-30g:30-40ml:30-50ml.

The ratio relationship of epoxy polyisoprene, toluene and methacrylic acid described in step (3) is 13-15g:50-70ml:20-30ml.

The mass ratio of grafted methacrylic acid epoxidized polyisoprene, hexamethylene diisocyanate and 6-methylisocytosine described in step (4) is 10-30:10-30:10- 30, preferably 10:20:10.

In the prior art, a terminal hydroxyl group is generated at each molecular chain end, and only one UPy group can be formed, and the hydrogen bond force is not strong enough. Compared with the prior art, the polyisoprene elastomer prepared by the present invention On both sides of each molecular chain, m-chloroperoxybenzoic acid can react with the pendant double bond of each isoprene on the molecular chain to generate many hydroxyl sites, and then react with hexamethylene diisocyanate and 6-methyl isoprene Pyrimidine reaction, so that more UPy groups can be generated, and the polyisoprene elastomer has more excellent performance through stronger quadruple hydrogen bonding.

The polymerization of isoprene adopts bulk anionic polymerization, and adopts the process conditions given in this application to produce polyisoprene with relatively large molecular weight and narrow molecular weight distribution, so it has good processability. The epoxidation treatment can generate many epoxy groups on both sides of the polyisoprene molecular chain, and the methacrylic acid treatment can make the ring-opening of the epoxy groups on both sides of the polyisoprene molecular chain generate many hydroxyl groups. The hydroxyl groups react with hexamethylene diisocyanate and 6-methylisocytosine to self-assemble into UPy groups. Adopting the ratio and reaction conditions of the present application can make the raw materials react in proportion in the reaction, thereby ensuring self-assembly into more UPy groups, higher raw material utilization rate, and better performance of the generated supramolecular elastomer.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

The DMA-242 dynamic mechanical analyzer produced by Germany NETZSCH was used to test the damping performance of the elastomer;

Use GB 528-83 to test the mechanical properties of elastomers;

Elastomers were characterized using Nicolet FT-IR370.

Comparative example 1

Degas the dry four-necked flask, add 30ml of isoprene and 0.3ml of sec-butyllithium into the four-necked flask under nitrogen atmosphere, react at 5°C for 4h, and finally inject 3ml of degassed methanol to terminate, pour into Precipitate in 10ml of isopropanol to obtain polyisoprene. Take 20g of polyisoprene, add 30ml of m-chloroperoxybenzoic acid and 30ml of methylene chloride solution, and react for 4 hours below 0°C. After the reaction is complete, suction filter the unreacted Washing with sodium bicarbonate solution and sodium chloride solution three times, separating the organic phase and drying with anhydrous magnesium sulfate, removing dichloromethane to obtain epoxidized polyisoprene. Take 13g of epoxidized polyisoprene, dissolve it in 50ml of toluene, add 20ml of methacrylic acid dropwise, and reflux at 100°C for 24h. Diene.

Table 1 shows the infrared spectrum characterization of ordinary grafted methacrylic acid epoxidized polyisoprene; its loss factor and tensile strength are shown in Table 2.

Comparative example 2

Degas the dry four-necked flask, add 40ml of isoprene and 0.4ml of sec-butyllithium into the four-necked flask under nitrogen atmosphere, react at 10°C for 5h, and finally inject 4ml of degassed methanol to terminate, pour into Precipitate in 15ml of isopropanol to obtain polyisoprene. Take 25g of polyisoprene, add 35ml of m-chloroperoxybenzoic acid and 40ml of methylene chloride solution, and react for 5 hours below 0°C. Washing with sodium bicarbonate solution and sodium chloride solution three times, separating the organic phase and drying with anhydrous magnesium sulfate, removing dichloromethane to obtain epoxidized polyisoprene. Take 14g of epoxidized polyisoprene, dissolve it in 60ml of toluene, add 25ml of methacrylic acid dropwise, and reflux at 100°C for 24 hours. Diene.

Table 1 shows the infrared spectrum characterization of ordinary grafted methacrylic acid epoxidized polyisoprene; its loss factor and tensile strength are shown in Table 2.

Comparative example 3

Degas the dry four-necked flask, add 50ml of isoprene and 0.5ml of sec-butyllithium into the four-necked flask under nitrogen atmosphere, react at 20°C for 6h, and finally inject 5ml of degassed methanol to terminate, pour into Precipitate in 20ml of isopropanol to obtain polyisoprene. Take 30g of polyisoprene, add 40ml of m-chloroperoxybenzoic acid and 50ml of methylene chloride solution, and react for 6 hours below 0°C. Washing with sodium bicarbonate solution and sodium chloride solution three times, separating the organic phase and drying with anhydrous magnesium sulfate, removing dichloromethane to obtain epoxidized polyisoprene. Take 15g of epoxidized polyisoprene, dissolve it in 70ml of toluene, add 30ml of methacrylic acid dropwise, and reflux at 100°C for 24 hours. Diene.

Table 1 shows the infrared spectrum characterization of ordinary grafted methacrylic acid epoxidized polyisoprene; its loss factor and tensile strength are shown in Table 2.

Example 1

Degas the dry four-necked flask, add 30ml of isoprene and 1ml of sec-butyllithium into the four-necked flask under nitrogen atmosphere, react at 20°C for 4h, finally inject 3ml of degassed methanol to terminate, pour 10ml Precipitation in isopropanol yielded polyisoprene. Take 20g of polyisoprene, add 30ml of m-chloroperoxybenzoic acid and 30ml of methylene chloride solution, and react for 4 hours below 0°C. After the reaction is complete, suction filter the unreacted Washing with sodium bicarbonate solution and sodium chloride solution three times, separating the organic phase and drying with anhydrous magnesium sulfate, removing dichloromethane to obtain epoxidized polyisoprene. Take 13g of epoxidized polyisoprene, dissolve it in 50ml of toluene, add 20ml of methacrylic acid dropwise, and reflux at 100°C for 24h. Diene. Get 10g grafted methacrylic acid epoxidized polyisoprene, add 10g hexamethylene diisocyanate, stir 3h under nitrogen atmosphere and room temperature, generate the epoxidized polyisoprene that end group is NCO, then Add 10 g of 6-methylisocytosine, stir at room temperature for 30 min in a nitrogen atmosphere, then raise the temperature to 20 ° C and keep for 3 h to obtain a white viscous substance, that is, polyisoprene supramolecular elasticity containing UPy groups. body.

The characterization of the infrared spectrum of the UPy modified polyisoprene elastomer is shown in Table 1; its loss factor and tensile strength are shown in Table 2.

Example 2

Degas the dry four-necked flask, add 40ml of isoprene and 2ml of sec-butyllithium into the four-necked flask under nitrogen atmosphere, react at 25°C for 5h, finally inject 4ml of degassed methanol to terminate, pour 15ml Precipitation in isopropanol yielded polyisoprene. Take 25g of polyisoprene, add 35ml of m-chloroperoxybenzoic acid and 40ml of methylene chloride solution, and react for 5 hours below 0°C. Washing with sodium bicarbonate solution and sodium chloride solution three times, separating the organic phase and drying with anhydrous magnesium sulfate, removing dichloromethane to obtain epoxidized polyisoprene. Take 14g of epoxidized polyisoprene, dissolve it in 60ml of toluene, add 25ml of methacrylic acid dropwise, and reflux at 100°C for 24 hours. Diene. Get 20g grafted methacrylic acid epoxidized polyisoprene, add 20g hexamethylene diisocyanate, stir 4h under nitrogen atmosphere and room temperature, generate end group to be the epoxidized polyisoprene of NCO, then Add 20g of 6-methylisocytosine, stir at room temperature for 40min in a nitrogen atmosphere, then raise the temperature to 30°C and keep for 4h to obtain a white viscous substance, that is, a polyisoprene supramolecular elastic substance containing UPy groups. body.

The characterization of the infrared spectrum of the UPy modified polyisoprene elastomer is shown in Table 1; its loss factor and tensile strength are shown in Table 2.

Example 3

Degas the dry four-necked flask, add 50ml of isoprene and 3ml of sec-butyllithium into the four-necked flask under nitrogen atmosphere, react at 30°C for 6h, finally inject 5ml of degassed methanol to terminate, pour 20ml Polyisoprene was obtained by precipitation in isopropanol. Take 30g of polyisoprene, add 40ml of m-chloroperoxybenzoic acid and 50ml of methylene chloride solution, and react for 6 hours below 0°C. Washing with sodium bicarbonate solution and sodium chloride solution three times, separating the organic phase and drying with anhydrous magnesium sulfate, removing dichloromethane to obtain epoxidized polyisoprene. Take 15g of epoxidized polyisoprene, dissolve it in 70ml of toluene, add 30ml of methacrylic acid dropwise, and reflux at 100°C for 24 hours. Diene. Get 30g grafted methacrylic acid epoxidized polyisoprene, add 30g hexamethylene diisocyanate, stir 5h under nitrogen atmosphere and room temperature, generate end group to be the epoxidized polyisoprene of NCO, then Add 30g of 6-methylisocytosine, stir at room temperature for 50min in a nitrogen atmosphere, then raise the temperature to 40°C and keep for 5h to obtain a white viscous substance, that is, polyisoprene supramolecular elasticity containing UPy groups. body.

The characterization of the infrared spectrum of the UPy modified polyisoprene elastomer is shown in Table 1; its loss factor and tensile strength are shown in Table 2.

Table 1 Infrared spectrum characterization

Table 2 Loss factor, tensile strength of polyisoprene elastomer

Example 4

A method for preparing polyisoprene supramolecular elastomer, adopts the following steps:

(1) Preparation of polyisoprene

Under a nitrogen atmosphere, mix isoprene and sec-butyl lithium, control the temperature at 0°C and react for 6 hours, then inject degassed methanol to terminate, pour into isopropanol to precipitate, isoprene, sec-butyl lithium, The volume ratio of methanol and isopropanol is 30:0.3:3:10 to obtain white viscous polyisoprene;

(2) Preparation of epoxidized polyisoprene

Place polyisoprene and m-chloroperoxybenzoic acid in dichloromethane, the ratio of polyisoprene, m-chloroperoxybenzoic acid and methylene chloride is 20g:30ml:30ml, and the temperature is controlled at zero degrees Following the reaction for 4h, the unreacted m-chloroperoxybenzoic acid filtrate was suction filtered, washed three times with saturated sodium bicarbonate solution and sodium chloride solution, the organic phase was separated and dried with anhydrous magnesium sulfate, and the ring was obtained after removing dichloromethane. Oxidized polyisoprene;

(3) Preparation of grafted methacrylic acid epoxy polyisoprene

Dissolve epoxy polyisoprene in toluene, reflux at 100°C for 24 hours after adding dropwise methacrylic acid, the ratio of epoxy polyisoprene, toluene and methacrylic acid is 13g:50ml:20ml, the reaction is over Rear decompression rotary steaming goes out grafted methacrylic acid epoxy polyisoprene;

(4) Preparation of polyisoprene elastomer

Stir the grafted methacrylic acid epoxidized polyisoprene and hexamethylene diisocyanate under nitrogen atmosphere and room temperature for 3 hours to generate epoxidized polyisoprene with NCO terminal group, and then add 6-methanol The mass ratio of grafted methacrylic acid epoxidized polyisoprene, hexamethylene diisocyanate and 6-methylisocytosine is 10:10:30, stirred at room temperature under nitrogen atmosphere After 30 minutes, the temperature was raised to 20° C. and kept for 5 hours to obtain a polyisoprene supramolecular elastomer containing UPy groups.

Example 5

A method for preparing polyisoprene supramolecular elastomer, adopts the following steps:

(1) Preparation of polyisoprene

Under a nitrogen atmosphere, mix isoprene and sec-butyllithium, control the temperature at 5°C and react for 5 hours, then inject degassed methanol to terminate, pour into isopropanol to precipitate, isoprene, sec-butyllithium, The volume ratio of methanol and isopropanol is 40:0.5:4:16 to obtain white viscous polyisoprene;

(2) Preparation of epoxidized polyisoprene

Place polyisoprene and m-chloroperoxybenzoic acid in dichloromethane, the ratio of polyisoprene, m-chloroperoxybenzoic acid and methylene chloride is 22g:35ml:40ml, and the temperature is controlled at zero degrees Following the reaction for 5h, the unreacted m-chloroperoxybenzoic acid filtrate was filtered by suction, washed three times with saturated sodium bicarbonate solution and sodium chloride solution, the organic phase was separated and dried with anhydrous magnesium sulfate, and the ring was obtained after removing methylene chloride. Oxidized polyisoprene;

(3) Preparation of grafted methacrylic acid epoxy polyisoprene

Dissolve epoxy polyisoprene in toluene, reflux at 100°C for 24 hours after adding dropwise methacrylic acid, the ratio of epoxy polyisoprene, toluene and methacrylic acid is 14g:65ml:25ml after the reaction Evaporating grafted methacrylic acid epoxy polyisoprene under reduced pressure;

(4) Preparation of polyisoprene elastomer

Stir the grafted methacrylic acid epoxidized polyisoprene and hexamethylene diisocyanate under nitrogen atmosphere and room temperature for 4 hours to generate epoxidized polyisoprene with NCO terminal group, and then add 6-methanol The mass ratio of grafted methacrylic acid epoxidized polyisoprene, hexamethylene diisocyanate and 6-methylisocytosine is 10:20:10, stirred at room temperature under nitrogen atmosphere After 40 minutes, the temperature was raised to 30°C and kept for 4 hours to obtain a polyisoprene supramolecular elastomer containing UPy groups.

Example 6

A method for preparing polyisoprene supramolecular elastomer, adopts the following steps:

(1) Preparation of polyisoprene

Under a nitrogen atmosphere, mix isoprene and sec-butyllithium, control the temperature at 20°C and react for 4 hours, then inject degassed methanol to terminate, pour into isopropanol to precipitate, isoprene, sec-butyllithium, The volume ratio of methanol and isopropanol is 50:0.5:5:20 to obtain white viscous polyisoprene;

(2) Preparation of epoxidized polyisoprene

Place polyisoprene and m-chloroperoxybenzoic acid in methylene chloride, the ratio of polyisoprene, m-chloroperoxybenzoic acid and methylene chloride is 30g:40ml:50ml, and the temperature is controlled at zero degrees Following the reaction for 6 hours, the unreacted m-chloroperoxybenzoic acid filtrate was filtered with suction, washed three times with saturated sodium bicarbonate solution and sodium chloride solution, the organic phase was separated and dried with anhydrous magnesium sulfate, and the ring was obtained after removing dichloromethane. Oxidized polyisoprene;

(3) Preparation of grafted methacrylic acid epoxy polyisoprene

Dissolve epoxy polyisoprene in toluene, reflux at 100°C for 24 hours after adding dropwise methacrylic acid, the ratio of epoxy polyisoprene, toluene and methacrylic acid is 15g:70ml:30ml, the reaction is over Rear decompression rotary steaming goes out grafted methacrylic acid epoxy polyisoprene;

(4) Preparation of polyisoprene elastomer

Stir the grafted methacrylic acid epoxidized polyisoprene and hexamethylene diisocyanate under nitrogen atmosphere and room temperature for 3-5h to generate epoxidized polyisoprene with NCO terminal group, then add 6 -Methylisocytosine, the mass ratio of grafted methacrylic acid epoxidized polyisoprene, hexamethylene diisocyanate and 6-methylisocytosine is 30:10:10, under nitrogen atmosphere and room temperature After stirring at low temperature for 50 minutes, the temperature was raised to 40° C. and kept for 3 hours to obtain a polyisoprene supramolecular elastomer containing UPy groups.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (7)

1. a method for preparing polyisoprene supramolecular elastomer, is characterized in that, the method adopts the following steps: (1) Preparation of polyisoprene Under a nitrogen atmosphere, mix isoprene and sec-butyllithium, control the temperature at 0-20°C and react for 4-6 hours, then inject degassed methanol to terminate, pour into isopropanol to precipitate, and obtain white viscous Polyisoprene; (2) Preparation of epoxidized polyisoprene Put polyisoprene and m-chloroperoxybenzoic acid in dichloromethane, control the temperature below zero to react for 4-6h, filter the unreacted m-chloroperoxybenzoic acid filtrate with saturated sodium bicarbonate solution and Washing with sodium chloride solution three times, separating the organic phase and drying with anhydrous magnesium sulfate, and obtaining epoxidized polyisoprene after removing methylene chloride; (3) Preparation of grafted methacrylic acid epoxy polyisoprene Dissolve epoxy polyisoprene in toluene, reflux at 100°C for 24 hours after adding methacrylic acid dropwise, and spin-evaporate grafted methacrylic acid epoxy polyisoprene after the reaction is completed; (4) Preparation of polyisoprene elastomer Stir the grafted methacrylic acid epoxidized polyisoprene and hexamethylene diisocyanate under nitrogen atmosphere and room temperature for 3-5h to generate epoxidized polyisoprene with NCO terminal group, and then add 6 - Methylisocytosine, after stirring for 30-50 minutes in a nitrogen atmosphere at room temperature, the temperature is raised to 20-40° C. and kept for 3-5 hours to obtain a polyisoprene supramolecular elastomer containing UPy groups. 2. a kind of method preparing polyisoprene supramolecular elastomer according to claim 1, is characterized in that, isoprene, sec-butyllithium, methyl alcohol, isopropyl described in step (1) The volume ratio of alcohol is 30-50:0.3-0.5:3-5:10-20. 3. a kind of method for preparing polyisoprene supramolecular elastomer according to claim 1, is characterized in that, the temperature of step (1) is 5-10 ℃. 4. a kind of method preparing polyisoprene supramolecular elastomer according to claim 1, is characterized in that, polyisoprene, m-chloroperoxybenzoic acid, dichloroperoxybenzoic acid described in step (2) The ratio of methyl chloride is 20-30g:30-40ml:30-50ml. 5. a kind of method preparing polyisoprene supramolecular elastomer according to claim 1, is characterized in that, the epoxy polyisoprene, toluene and methacrylic acid described in step (3) The ratio is 13-15g:50-70ml:20-30ml. 6. a kind of method preparing polyisoprene supramolecular elastomer according to claim 1, is characterized in that, the graft methacrylic acid epoxidized polyisoprene described in step (4), The mass ratio of hexamethylene diisocyanate and 6-methylisocytosine is 10-30:10-30:10-30. 7. a kind of method preparing polyisoprene supramolecular elastomer according to claim 1, is characterized in that, the graft methacrylic acid epoxidized polyisoprene described in step (4), The mass ratio of hexamethylene diisocyanate and 6-methylisocytosine is 10:20:10.