CN112266429A

CN112266429A - Nitrogen-phosphorus flame-retardant polybutadiene material and preparation method thereof

Info

Publication number: CN112266429A
Application number: CN202011111364.9A
Authority: CN
Inventors: 邓万菁
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-10-16
Filing date: 2020-10-16
Publication date: 2021-01-26

Abstract

The invention discloses a nitrogen-phosphorus flame-retardant polybutadiene material and a preparation method thereof; by grafting a nitrogen-phosphorus flame retardant on a polybutadiene molecular chain, a nitrogen-phosphorus flame-retardant polybutadiene material is obtained, so that the polybutadiene molecule has flame retardance; the problems that the bonding action force between flame retardant molecules and a polybutadiene substrate is weak, the loss of flame retardant components is caused, the long-term flame retardant performance of a product is influenced and the dispersion uniformity of the flame retardant is not easy to guarantee because the flame retardant molecules and the polybutadiene substrate are only subjected to physical mixing action without chemical bonding action are solved, smoke is not generated in the processing engineering of the polybutadiene material, and the obtained polybutadiene material has lasting flame retardant performance.

Description

Nitrogen-phosphorus flame-retardant polybutadiene material and preparation method thereof

Technical Field

The invention belongs to the field of polymer chemical synthesis, and particularly relates to a nitrogen-phosphorus flame-retardant polybutadiene material and a preparation method thereof.

Background

Polybutadiene is mainly used as synthetic rubber, and solution polymerized polybutadiene is often used together with styrene-butadiene rubber or natural rubber as a tread and a carcass of a tire; in addition, because it is wear-resistant, it can be used as the wrapping of conveyer belt, sole, motorcycle parts, etc.; 1, 2-polybutadiene is mainly used as an adhesive and a sealant.

In some cases, it is desirable that the rubber have some specific properties, such as flame retardant properties. Polybutadiene rubber is easy to burn, and in order to improve the flame retardant performance of polybutadiene rubber, a method generally adopted in the prior art is to add a flame retardant. Commonly used flame retardants include phosphorus-nitrogen based flame retardants, halogen-containing flame retardants or inorganic flame retardants (such as magnesium hydroxide, aluminum hydroxide or calcium hydroxide, etc.); however, the phosphorus-nitrogen flame retardant is easy to generate smoke in the processing and using process of the material; the halogen-containing flame retardant is easy to generate hydrogen halide gas in the using process, and has great harm to the environment and human bodies; the inorganic flame retardant is clean, pollution-free, wide in source and low in price, but can show a flame retardant effect only under the condition of a large addition amount; in addition, the larger the addition amount of the inorganic flame retardant is, the more the negative effect on the mechanical properties of the material is. Based on the above, the invention provides a nitrogen-phosphorus flame-retardant polybutadiene material and a preparation method thereof.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides the nitrogen-phosphorus flame-retardant polybutadiene material and the preparation method thereof, wherein nitrogen-phosphorus flame retardant molecules are grafted on a polybutadiene molecular chain, so that smoke is not generated in the polybutadiene material in the processing engineering, the problem of poor compatibility between the molecules and the flame retardant does not exist, and the obtained polybutadiene material has lasting flame retardant performance.

The invention aims to provide a nitrogen-phosphorus flame-retardant polybutadiene material.

The invention also aims to provide a preparation method of the nitrogen-phosphorus flame-retardant polybutadiene material.

The above purpose of the invention is realized by the following technical scheme:

the nitrogen-phosphorus flame-retardant polybutadiene material has a structural formula shown as the following formula (I):

wherein n is 25-50.

The reaction process and the preparation method of the nitrogen-phosphorus flame-retardant polybutadiene material are as follows:

the preparation method of the nitrogen-phosphorus flame-retardant polybutadiene material comprises the following steps:

1. adding carboxyl-terminated polybutadiene and anhydrous tetrahydrofuran THF into a reactor, slowly dropwise adding SOCl after the reaction temperature rises to 70 DEG C₂After the dropwise addition, the reaction is carried out for 2 hours,after the reaction was completed, SOCl was removed by distillation under reduced pressure₂And THF to afford the carboxyl-terminated polybutadiene acylchlorination product.

Wherein, carboxyl terminated polybutadiene and SOCl₂In a molar ratio of 1: 5.

2. Adding nitrogen and phosphorus flame retardant into a Schlenk bottle, and pumping and filling nitrogen for three times, wherein N is₂Under protection, 30ml of anhydrous toluene is added into a disposable injector, the temperature is raised to 70 ℃, pyridine is injected after the nitrogen and phosphorus flame retardant is completely dissolved, the mixture is stirred for 30min, the carboxyl-terminated polybutadiene acyl chlorination product dissolved in the toluene is dropwise added, the temperature is raised to 80 ℃, the reaction is continued for 3h, the product is cooled to room temperature, and after two times of continuous dissolution/precipitation circulation of the toluene/methanol, the product is dried to constant weight under vacuum at 45 ℃, and the nitrogen and phosphorus flame-retardant polybutadiene material is obtained.

Wherein the molar ratio of the nitrogen-phosphorus flame retardant to the carboxyl-terminated polybutadiene acyl chloride product is 10: 1.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the invention provides a nitrogen-phosphorus flame-retardant polybutadiene material, which enables polybutadiene molecules to have flame retardance by grafting a flame retardant on a polybutadiene molecular chain.

(2) The invention provides a nitrogen-phosphorus flame-retardant polybutadiene material, which solves the problems that chemical bonding does not exist due to the fact that flame retardant molecules and a polybutadiene substrate are only subjected to physical mixing, the bonding acting force between the flame retardant molecules and the polybutadiene substrate is weak, flame retardant components are lost, the long-term flame retardant performance of a product is influenced, the uniformity of dispersion of a flame retardant is not easy to guarantee, smoke is not generated in the processing engineering of the polybutadiene material, and the obtained polybutadiene material has lasting flame retardant performance.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum diagram of a nitrogen-phosphorus flame-retardant polybutadiene material.

Detailed Description

The present invention will be described in further detail with reference to specific examples, which are not intended to limit the present invention in any manner. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Example 1

Carboxyl-terminated polybutadiene (2.0mmol) and anhydrous tetrahydrofuran THF are added into a reactor, after the reaction temperature rises to 70 ℃, SOCl is slowly dropped₂(10.0mmol) and reacted for 2h after the dropwise addition, after the reaction was complete, SOCl was removed by distillation under reduced pressure₂And THF gave the carboxyl-terminated polybutadiene in 78.4% yield.

Example 2

Adding nitrogen-phosphorus flame retardant (1.0mmol) into a 50mL Schlenk bottle, pumping nitrogen for three times, and then adding N₂Under protection, 30ml of anhydrous toluene is added into a disposable syringe, the temperature is raised to 70 ℃, 1ml of pyridine is injected after the nitrogen and phosphorus flame retardant is completely dissolved, the mixture is stirred for 30min, the carboxyl-terminated polybutadiene acyl chloride product (10.0mmol) dissolved in the toluene is dripped, the temperature is raised to 80 ℃, the reaction is continued for 3h, the product is cooled to room temperature, and after the continuous dissolution/precipitation circulation of the toluene/methanol is carried out twice, the product is dried to constant weight under vacuum at 45 ℃, and the nitrogen and phosphorus flame-retardant polybutadiene material is obtained, wherein the yield is 80.2%.

Example 3

Before processing, the nitrogen-phosphorus flame-retardant polybutadiene material is dried in vacuum for 12 hours at the temperature of 80 ℃, 60 wt% of the nitrogen-phosphorus flame-retardant polybutadiene material is added on an open type heat mixer with the double-roll temperature of 225 ℃, after the nitrogen-phosphorus flame-retardant polybutadiene material is melted and wrapped on a roll, the mixture is mixed for 10min and then evenly taken out, the mixture is hot-pressed for 10min at the temperature of 230 ℃ on a flat vulcanizing machine, cold-pressed for 8min at room temperature and taken out, various standard sample strips are prepared on a universal sampling machine, and the flame-retardant performance test is carried out.

Example 4

Before processing, the nitrogen-phosphorus flame-retardant polybutadiene material is dried in vacuum for 12 hours at 80 ℃, 80 wt% of the nitrogen-phosphorus flame-retardant polybutadiene material is added on an open type heat mixer with a double-roller temperature of 225 ℃, after the nitrogen-phosphorus flame-retardant polybutadiene material is melted and wrapped on a roller, the mixture is mixed for 10min and then evenly taken out, the mixture is hot-pressed for 10min at 230 ℃ on a flat vulcanizing machine, cold-pressed for 8min at room temperature and taken out, various standard sample strips are prepared on a universal sampling machine, and the flame-retardant performance test is carried out.

Example 5

Before processing, the nitrogen-phosphorus flame-retardant polybutadiene material is dried in vacuum for 12 hours at the temperature of 80 ℃, 100 wt% of the nitrogen-phosphorus flame-retardant polybutadiene material is added on an open type heat mixer with the double-roll temperature of 225 ℃, after the nitrogen-phosphorus flame-retardant polybutadiene material is melted and wrapped on a roll, the mixture is mixed for 10min and then evenly taken out, the mixture is hot-pressed for 10min at the temperature of 230 ℃ on a flat vulcanizing machine, cold-pressed for 8min at room temperature and taken out, various standard sample strips are prepared on a universal sampling machine, and the flame-retardant performance test is carried out.

Comparative example 1

Before processing, polybutadiene is dried in vacuum at 80 ℃ for 12h, 100 wt% of polybutadiene is added into an open type heat mixing machine with a double-roller temperature of 225 ℃, after the polybutadiene is melted and coated on a roller, the polybutadiene is mixed for 10min and then evenly taken out, hot pressing is carried out on a flat vulcanizing machine at 230 ℃ for 10min, cold pressing is carried out at room temperature for 8min, the polybutadiene is taken out, various standard sample strips are prepared on a universal sampling machine, and the flame retardant performance test is carried out.

Limiting oxygen index test: the instrument is FTAII (1600) type limit oxygen index instrument of RS company in UK, test standard GB/T2406.2-2009, spline specification 100mm x 6mm x 3mm, and a group of 5-10, before test, the spline is placed in an environment with temperature 23 + -2 deg.C and humidity 50 + -5% and adjusted for more than 88 h.

UL-94 vertical burning test: the instrument is an CZF-5A horizontal vertical combustion tester of Jiangning analytical instruments factory for carrying out UL-94 vertical combustion test, the specification of the sample bar is 125mm multiplied by 13mm multiplied by 3.2mm, and the test standard is UL94ISBN 0-7629 and 0082-2. Before testing, the sample is put in an environment with the temperature of 23 +/-2 ℃ and the humidity of 50 +/-5% and is adjusted for more than 48 h.

Tensile strength was determined according to standard HG/T2580-.

The bending strength was determined according to the standard GB/T12585-2001.

Table 1 shows the flame retardant properties and mechanical properties of the nitrogen-phosphorus flame retardant polybutadiene material.

Sample (I)	LOI(％)	UL-94	Tensile Strength (MPa)	Flexural Strength (MPa)
					Example 3	31.2	V-1	54	106
Example 4	33.0	V-1	55	107
					Example 5	35.3	V-1	53	103
Comparative example 1	18.3	N.R	56	102

As can be seen from Table 1, the flame retardant property of polybutadiene is obviously improved by grafting nitrogen and phosphorus on a polybutadiene polymer chain. As can be seen from the comparison of the data of the example 3 and the comparative example 1, the LOI of the pure polybutadiene is only 18.0%, when the polybutadiene is modified by grafting nitrogen and phosphorus flame retardant on a polybutadiene polymer chain, the LOI can reach 35.3%, the flame retardant property of the polyphenylene butadiene is effectively improved, and the introduction of the nitrogen and phosphorus flame retardant groups is not large for the mechanical property of the polybutadiene.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. The nitrogen-phosphorus flame-retardant polybutadiene material is characterized by having a structure shown in a formula (I):

wherein n is 25-50.

2. The preparation method of the nitrogen-phosphorus flame-retardant polybutadiene material according to claim 1, wherein the preparation method comprises the following steps:

(1) adding carboxyl-terminated polybutadiene and anhydrous tetrahydrofuran THF into a reactor, slowly dropwise adding SOCl after the reaction temperature rises to 70 DEG C₂After the dropwise addition, the reaction was carried out for 2 hours, and after the completion of the reaction, SOCl was removed by distillation under reduced pressure₂And THF to obtain carboxyl-terminated polybutadiene acyl chloride product;

(2) adding nitrogen and phosphorus flame retardant into a Schlenk bottle, and pumping and filling nitrogen for three times, wherein N is₂Under protection, adding 30ml of anhydrous toluene into a disposable injector, heating to 70 ℃, injecting pyridine after the nitrogen and phosphorus flame retardant is completely dissolved, stirring for 30min, dropwise adding the carboxyl-terminated polybutadiene acyl chlorination product dissolved in the toluene, heating to 80 ℃, continuing to react for 3h, cooling the product to room temperature, continuously dissolving/precipitating with toluene/methanol twice, and drying at the temperature of 45 ℃ in vacuum to constant weight to obtain the nitrogen and phosphorus flame-retardant polybutadiene material。

3. The method for preparing nitrogen-phosphorus flame-retardant polybutadiene material according to claim 2, wherein in step (1), the carboxyl-terminated polybutadiene and SOCl are adopted₂In a molar ratio of 1: 5.

4. The method for preparing nitrogen-phosphorus flame-retardant polybutadiene material according to claim 2, wherein in step (2), the molar ratio of the nitrogen-phosphorus flame retardant to the carboxyl-terminated polybutadiene acylchlorination product is 10: 1.