Phosphorylated polyphenyl ether and preparation method thereof

Abstract

The invention relates to the technical field of polyphenyl ether, in particular to phosphorylated polyphenyl ether and a preparation method thereof. The phosphorylated polyphenyl ether provided by the invention has a structure as shown in a formula 1; the content of the P element in the phosphorylated polyphenyl ether is 0.5 to 5 weight percent. According to the invention, phosphorylation modification is carried out on polyphenyl ether, so that the obtained phosphorylated polyphenyl ether can reach a UL-94V-0 level flame retardant effect under the condition that the P element content is relatively low. The invention provides a preparation method of the phosphorylated polyphenyl ether. The phosphorylated polyphenyl ether can be prepared by carrying out nucleophilic substitution reaction on brominated polyphenyl ether by adopting dimethyl methylphosphonate. Compared with modification of polyphenyl ether with expensive DOPO, the price of dimethyl methylphosphonate used in the method is lower, and the production cost is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of polyphenylene ether, and in particular to a phosphorylated polyphenylene ether and a preparation method and application thereof. Background Art

[0002] Polyphenylene ether (PPO) is a thermoplastic engineering plastic with excellent performance, which has the advantages of low density, non-toxicity, good creep resistance, low molding shrinkage, high glass transition temperature (Tg), and good electrical properties. Among them, high creep resistance is its most prominent feature, so polyphenylene ether is particularly suitable for making industrial structural parts that bear long-term loads. However, polyphenylene ether also has some disadvantages, such as poor flame retardancy, which affects the promotion and application of polyphenylene ether.

[0003] In the related technology, polyphenylene ether is brominated and modified with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to prepare phosphated polyphenylene ether with different phosphorus contents. Compared with pure polyphenylene ether, the phosphated polyphenylene ether has higher solubility and better flame retardancy. However, the DOPO used in this preparation method is costly and is not suitable for mass production by enterprises.

[0004] Therefore, there is an urgent need to develop a low-cost modified polyphenylene ether material that can achieve a flame retardant effect of UL94V-0 level. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a phosphorylated polyphenylene ether and a preparation method and application thereof. The phosphorylated polyphenylene ether has low cost and can achieve a flame retardant effect of UL94V-0 grade.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a phosphorylated polyphenylene ether having a structure shown in Formula 1:

[0008]

[0009] The content of P element in the phosphated polyphenylene ether is 0.5-5 wt %.

[0010] The present invention provides a method for preparing the phosphorylated polyphenylene ether described in the above scheme, comprising the following steps: mixing a brominated polyphenylene ether having a structure shown in Formula 2 and dimethyl methyl phosphate, and performing a nucleophilic substitution reaction to obtain the phosphorylated polyphenylene ether;

[0011] The brominated polyphenylene ether has a bromination degree of 4 to 16 wt %;

[0012] The molar ratio of the brominated polyphenylene ether to dimethyl methyl phosphate is 1.1 to 10:1;

[0013]

[0014] Preferably, the temperature of the nucleophilic substitution reaction is 160-200°C.

[0015] Preferably, the nucleophilic substitution reaction time is 9 to 12 hours.

[0016] Preferably, the nucleophilic substitution reaction is carried out under protective gas conditions.

[0017] Preferably, after the nucleophilic substitution reaction is completed, the method further comprises adding the obtained mixture into ethanol to precipitate the product, washing the obtained precipitate with water and then drying to obtain the phosphorylated polyphenylene ether.

[0018] Preferably, the preparation of the brominated polyphenylene ether comprises: mixing polyphenylene ether, N-bromosuccinimide, an azo initiator and a polar organic solvent, and performing a bromination reaction to obtain the brominated polyphenylene ether.

[0019] Preferably, the molar ratio of the polyphenylene ether to N-bromosuccinimide is 1:(0.09-0.3).

[0020] Preferably, the temperature of the bromination reaction is 130-160° C., and the time is 3-6 hours.

[0021] The present invention provides the use of the phosphorylated polyphenylene ether described in the above scheme or the phosphorylated polyphenylene ether prepared by the preparation method described in the above scheme as a flame retardant.

[0022] The present invention provides a phosphorylated polyphenylene ether having a structure shown in Formula 1; the content of P element in the phosphorylated polyphenylene ether is 0.5-5wt%. The present invention phosphorylates the polyphenylene ether to obtain a phosphorylated polyphenylene ether that can achieve a UL-94V-0 flame retardant effect with a low P element content.

[0023] The present invention provides a method for preparing the phosphorylated polyphenylene ether described in the above scheme, which can be prepared by using dimethyl methylphosphonate to perform a nucleophilic substitution reaction on brominated polyphenylene ether. Compared with DOPO (expensive, 100 yuan / kg) to modify polyphenylene ether, the price of dimethyl methylphosphonate used in the present invention is 15 to 20 yuan / kg, which greatly reduces the production cost. Moreover, the present invention does not require the use of a catalyst.

[0024] In addition, the maximum nucleophilic substitution reaction time of the present invention is 12 hours, which is significantly shortened compared to the modification with DOPO (time is 24 hours), further reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 For PPO 1 H NMR spectrum;

[0026] Figure 2 For and brominated PPO-1 1 H NMR spectrum;

[0027] Figure 3 Phosphorylation of PPO-1 1 H NMR spectrum;

[0028] Figure 4 is the infrared spectrum of brominated PPO-1;

[0029] Figure 5 This is the infrared spectrum of phosphorylated PPO-1. DETAILED DESCRIPTION

[0030] The present invention provides a phosphorylated polyphenylene ether having a structure shown in Formula 1:

[0031]

[0032] The content of P element in the phosphated polyphenylene ether is 0.5-5 wt %.

[0033] In the present invention, the subscripts a and b in Formula 1 represent the number of corresponding units respectively. The present invention does not make any special requirements on the specific values ​​of a and b, as long as the content of P element in the phosphated polyphenylene ether is 0.5-5wt%.

[0034] In a specific embodiment, the content of P element in the phosphorylated polyphenylene ether can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt% or 5wt%.

[0035] The present invention performs phosphorylation modification on polyphenylene ether, and the obtained phosphorylated polyphenylene ether can achieve the flame retardant effect of UL-94V-0 level under the condition of low P element content.

[0036] The present invention provides a method for preparing the phosphorylated polyphenylene ether described in the above scheme, comprising the following steps: mixing a brominated polyphenylene ether having a structure shown in Formula 2 and dimethyl methyl phosphate, and performing a nucleophilic substitution reaction to obtain the phosphorylated polyphenylene ether;

[0037] The brominated polyphenylene ether has a bromination degree of 4 to 16 wt %;

[0038] The molar ratio of the brominated polyphenylene ether to dimethyl methyl phosphate is 1.1 to 10:1;

[0039]

[0040] In the present invention, the preparation method of the brominated polyphenylene ether preferably comprises the following steps:

[0041] The polyphenylene ether, N-bromosuccinimide, an azo initiator and a polar organic solvent are mixed and subjected to a bromination reaction to obtain the brominated polyphenylene ether.

[0042] In the present invention, the molar ratio of the polyphenylene ether to N-bromosuccinimide (NBS) is preferably 1:(0.09-0.3), and in specific embodiments, it can be 1:0.09, 1:0.1, 1:0.15, 1:0.2, 1:0.25 or 1:0.3.

[0043] In the present invention, the azo initiator preferably includes azobisisobutyronitrile (AIBN); the polar organic solvent preferably includes chlorobenzene; the mass of the azo initiator is preferably 1-5% of the mass of the polyphenylene ether, and in a specific embodiment, it can be 1%, 2%, 3%, 4% or 5%. The present invention has no special requirements for the amount of the polar organic solvent, as long as it can ensure the bromination reaction.

[0044] In the present invention, the bromination reaction is preferably carried out under protective gas conditions, and the protective gas is preferably argon or nitrogen. In the present invention, the temperature of the bromination reaction is preferably 130-160°C, and the time is preferably 3-6 hours; in a specific embodiment, the temperature of the bromination reaction can be 130°C, 140°C, 150°C or 160°C, and the time of the bromination reaction can be 3 hours, 4 hours, 5 hours or 6 hours. In the present invention, the bromination reaction is preferably carried out under reflux conditions.

[0045] After the bromination reaction is completed, the present invention preferably cools the obtained mixture to room temperature, then pours it into n-hexane to precipitate the product, filters it, washes it with ethanol, and then dries it to obtain brominated polyphenylene ether.

[0046] In the present invention, when AIBN is used as an initiator, the reaction temperature is 130° C., and the reaction time is 4 h, the equation of the bromination reaction is as follows:

[0047]

[0048] In the present invention, the degree of bromination of the brominated polyphenylene ether is 4 to 16 wt %. In specific embodiments, it can be 4 wt %, 6 wt %, 8 wt %, 10 wt %, 12 wt %, 14 wt % or 16 wt %.

[0049] In the present invention, the degree of bromination is defined as the mass percentage of brominated polyphenylene ether units to the mass percentage of polyphenylene ether.

[0050] After obtaining the brominated polyphenylene ether, the present invention mixes the brominated polyphenylene ether and dimethyl methyl phosphate to carry out a nucleophilic substitution reaction to obtain the phosphorylated polyphenylene ether.

[0051] In the present invention, the molar ratio of the brominated polyphenylene ether to dimethyl methyl phosphate is preferably 1.1 to 10:1; in specific embodiments, it can be 1.1:1, 2:1, 3:1, 4:1, 6:1, 8:1 or 10:1.

[0052] In the present invention, the temperature of the nucleophilic substitution reaction is preferably 160-200°C, and the time is preferably 9-12h. In a specific embodiment, the temperature of the nucleophilic substitution reaction can be 160°C, 170°C, 180°C, 190°C or 200°C; the time of the nucleophilic substitution reaction can be 9h, 10h, 11h or 12h. In the present invention, the nucleophilic substitution reaction is preferably carried out under the condition of passing protective gas, and the protective gas is preferably nitrogen or argon.

[0053] In the present invention, the equation of the nucleophilic substitution reaction is as follows:

[0054]

[0055] After the nucleophilic substitution reaction is completed, the present invention preferably further comprises adding the obtained mixture into ethanol to precipitate the product, washing the obtained precipitate with water and then drying to obtain the phosphorylated polyphenylene ether.

[0056] Compared with using expensive DOPO to modify polyphenylene ether, the dimethyl methylphosphonate used in the present invention is cheap, which greatly reduces the production cost. Moreover, the present invention does not require the use of a catalyst.

[0057] The present invention provides the use of the phosphorylated polyphenylene ether described in the above scheme or the phosphorylated polyphenylene ether prepared by the preparation method described in the above scheme as a flame retardant.

[0058] The phosphorylated polyphenylene ether and the preparation method thereof provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0059] Example 1

[0060] PPO 10.0g (repeating unit: 82.54mmol), NBS 1.468g (8.254mmol), AIBN 0.20g and chlorobenzene 200mL were added to a round-bottom glass bottle equipped with a nitrogen inlet, a condenser and a magnetic stirrer. The reaction mixture was heated to a reflux temperature of 160°C under nitrogen and maintained at this temperature for 4h. The reaction mixture was then cooled to room temperature and poured into 500mL of n-hexane to precipitate the product. The precipitate was filtered, washed with ethanol, and then dried in a vacuum drying oven at 100°C to obtain brominated polyphenylene ether, recorded as brominated PPO-1.

[0061] 6.0 g of brominated PPO-1 and 25 g (200 mmol) of dimethyl methyl phosphate (DMMP) were introduced into a round-bottomed glass flask equipped with a nitrogen inlet and a magnetic stirrer. The reaction mixture was stirred at 180°C for 12 h. The reaction mixture was then cooled to room temperature, poured into 150 mL of ethanol to precipitate the product, washed with distilled water, and then dried in a vacuum oven at 100°C. The phosphorylated product was named phosphorylated PPO-1, and the phosphorus content determined by nuclear magnetic resonance integrated area analysis was 0.67 wt%.

[0062] Embodiment 2-3

[0063] The preparation method is the same as that of Example 1, the only difference being the amount of raw materials used.

[0064] The raw material dosage and product conditions of Examples 1 to 3 are shown in Tables 1 and 2.

[0065] Table 1 Preparation materials and degree of bromination of brominated polyphenylene ether

[0066]

[0067]

[0068] Table 2 Preparation raw materials and phosphorus content of phosphorylated polyphenylene ether

[0069] Brominated polyphenylene ether DMMP Molar ratio of brominated polyphenylene ether to DMMP Phosphorus content Phosphorylated polyphenylene ether Brominated PPO-16g 25g 2:1 0.67wt% Phosphorylation of PPO-1 Brominated PPO-26g 25g 4:1 2wt% Phosphorylation of PPO-2 Brominated PPO-36g 25g 8:1 4wt% Phosphorylation of PPO-3

[0070] Structural testing:

[0071] PPO, brominated PPO-1, and phosphorylated PPO-1 were measured by NMR in deuterated chloroform. Figures 1 to 3 ,in, Figure 1 For PPO 1 HNMR spectrum; Figure 2 For and brominated PPO-1 1 H NMR spectrum; Figure 3 Phosphorylation of PPO-1 1 HNMR spectrum of PPO and brominated PPO-1 1 From the H NMR spectrum, it can be seen that 7.25ppm is the solvent peak of deuterated chloroform, and the brominated PPO-1 has absorption of CH2Br at 2.77ppm and 1.55ppm. The bromination rate calculated from the ratio of signal integrated area CH2 / ArH is 4.3wt%. From the comparison spectra of brominated PPO-1 and phosphorylated PPO-1, it can be seen that the absorption rate of methylene of CH2-Br changes from 2.77ppm to 3.7-3.75ppm of CH2-P. The AreH signal generated by the benzene ring was observed under the condition of 6-7ppm, which proved the successful nucleophilic substitution of dimethyl methylphosphonate.

[0072] The infrared test results of brominated PPO-1 and phosphorylated PPO-1 are shown in Figure 4 and Figure 5 . By brominated PPO-1 ( Figure 4 ) and phosphorylated PPO-1( Figure 5 ) can be seen from the infrared spectrum that P=O stretching vibration appears at 1310cm -1 At 850cm -1 There is a sharp band at 2305-3300cm, which is the stretching vibration of phenylphosphine; -1 A new vibration peak appeared at the position, which corroborated with the NMR spectrum, proving the successful preparation of phosphorylated polyphenylene ether.

[0073] Performance Test:

[0074] The flame retardancy of phosphorylated polyphenylene ether was measured using the UL94VTM vertical test. Each sample was ignited twice. After the first ignition, the sample that had been burned out was ignited again and the second ignition time was recorded. The test results are shown in Table 3.

[0075] Table 3 Flame retardant properties of examples and PPO

[0076] Sample name Phosphorus content First burning time(s) Second burning time(s) UL-94 grade PPO 0 10.6 2.3 V-1 Phosphorylation of PPO-1 0.67wt% 2.7 1.2 V-0 Phosphorylation of PPO-2 2wt% 1.3 0.4 V-0 Phosphorylation of PPO-3 4wt% 1 0.1 V-0

[0077] It can be seen from Table 3 that phosphorus has good flame retardancy, and phosphorylated polyphenylene ether with a phosphorus content as low as 1.0 wt% can reach UL-94 V-0 grade.

[0078] Comparative Examples 1 to 3

[0079] Investigate the effect of different reactants on the flame retardancy of phosphated polyphenylene ether:

[0080] The only difference from Example 1 is that dimethyl methylphosphonate is replaced by equimolar amounts of trimethyl phosphate, triethyl phosphate and triphenyl phosphate, respectively. The specific reaction conditions and the yield of phosphorylated polyphenylene ether are shown in Table 4.

[0081] Table 4 Reaction conditions, yields and flame retardant properties of Example 1 and Comparative Examples 1 to 3

[0082] serial number Reactant 1 Reactant 2 Mole ratio of reactants Yield UL-94 grade Comparative Example 1 Brominated PPO-1 Trimethyl phosphate 2:1 - - Comparative Example 2 Brominated PPO-1 Triethyl phosphate 2:1 - - Comparative Example 3 Brominated PPO-1 Triphenyl phosphate 2:1 25％ V-1 Example 1 Brominated PPO-1 Dimethyl methylphosphonate 2:1 95％ V-0

[0083] From the results in Table 4, it can be seen that trimethyl phosphate and triethyl phosphate do not react with brominated polyphenylene ether, while triphenyl phosphate can react, but the yield is low. The flame retardancy test found that the flame retardancy does not reach the V0 level, and triphenyl phosphate has been officially included in the SVHC candidate substance list.

[0084] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A phosphorylated polyphenylene ether, characterized in that: It has the structure shown in formula 1: The content of P element in the phosphated polyphenylene ether is 0.5-5 wt %.

2. The method for preparing the phosphorylated polyphenylene ether according to claim 1, characterized in that: The method comprises the following steps: mixing a brominated polyphenylene ether having a structure shown in Formula 2 and dimethyl methyl phosphate, and performing a nucleophilic substitution reaction to obtain the phosphorylated polyphenylene ether; The brominated polyphenylene ether has a bromination degree of 4 to 16 wt %; The molar ratio of the brominated polyphenylene ether to dimethyl methyl phosphate is 1.1 to 10:1; 3. The preparation method according to claim 2, characterized in that: The temperature of the nucleophilic substitution reaction is 160-200°C.

4. The preparation method according to claim 2 or 3, characterized in that: The time of the nucleophilic substitution reaction is 9 to 12 hours.

5. The preparation method according to claim 2 or 3, characterized in that: The nucleophilic substitution reaction is carried out under protective gas conditions.

6. The preparation method according to claim 2, characterized in that: After the nucleophilic substitution reaction is completed, the obtained mixture is added into ethanol to precipitate the product, and the obtained precipitate is washed with water and then dried to obtain the phosphorylated polyphenylene ether.

7. The preparation method according to claim 2, characterized in that: The preparation of the brominated polyphenylene ether comprises: mixing polyphenylene ether, N-bromosuccinimide, an azo initiator and a polar organic solvent, and performing a bromination reaction to obtain the brominated polyphenylene ether.

8. The preparation method according to claim 7, characterized in that: The molar ratio of the polyphenylene ether to N-bromosuccinimide is 1:(0.09-0.3).

9. The preparation method according to claim 7, characterized in that: The temperature of the bromination reaction is 130-160° C. and the time is 3-6 hours.

10. Use of the phosphorylated polyphenylene ether according to claim 1 or the phosphorylated polyphenylene ether prepared by the preparation method according to any one of claims 2 to 9 as a flame retardant.

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