A rapidly vulcanizing hydrazide cured perfluoroelastomeric composition and method of making and use thereof

Abstract

The application provides a kind of fast vulcanized hydrazide cured perfluoroelastomer composition and its preparation method and application, and belongs to the field of chemical material processing.The application uses dihydrazide compound and metal magnesium promoter as curing system, and perfluoroelastomer composition is prepared by regulating raw material ratio.The perfluoroelastomer composition not only can be quickly vulcanized, but also has excellent mechanical properties, is suitable for commercial production, and has wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of chemical material processing, and particularly relates to a kind of acylhydrazine cured perfluoro elastomer composition, its preparation method and application. BACKGROUND

[0002] Perfluoroelastomer is a copolymer polymerized by tetrafluoroethylene (TFE), perfluoroalkyl vinyl ether (PAVE, including perfluoromethyl vinyl ether PMVE, perfluoroethyl vinyl ether PEVE, perfluoropropyl vinyl ether PPVE), third monomer (vulcanization point monomer CSM) and the like, which has excellent high temperature resistance and chemical medium resistance. The vulcanization site forms a crosslinked polymer by reacting with one or more curing agents, such as diamine compounds and peroxide compounds, so that the perfluoroelastomer has more stable and excellent mechanical properties.

[0003] The existing patent US8765876B2 proposes that when acylhydrazine is used as the curing system of perfluoroelastomer composition, it can be used for sealing elements of aircraft engines, oil well drilling devices and industrial equipment operating at high temperatures. However, this method has the following problems: the vulcanization time in the examples is generally long, all above 15 min, and such a curing rate is too slow for commercial production in pursuit of economic benefits. SUMMARY

[0004] In order to overcome the defects of the prior art, the purpose of the present application is to provide a kind of acylhydrazine cured perfluoro elastomer composition and its preparation method and application.

[0005] The present application provides a modified perfluoro elastomer composition, which is prepared from the following mass parts of raw materials: perfluoroelastomer 100 parts, diacylhydrazine compound 0.05-7 parts, magnesium oxide 0.1-3 parts.

[0006] Further, it is prepared from the following mass parts of raw materials: perfluoroelastomer 100 parts, diacylhydrazine compound 0.2-1.5 parts, magnesium oxide 0.1-2 parts;

[0007] Preferably, it is prepared from the following mass parts of raw materials: perfluoroelastomer 100 parts, diacylhydrazine compound 0.5 parts, magnesium oxide 1 part.

[0008] Further, the structure general formula of the diacylhydrazine compound is shown as formula I:

[0009]

[0010] wherein R is C 1-10 alkylene or aryl.

[0011] Further, the R is C1-5 Alkylene or aryl groups.

[0012] Furthermore, the perfluorinated elastomer is a copolymer unit containing a nitrile-based curing site monomer.

[0013] Furthermore, the perfluoroelastomer is a perfluoroether rubber;

[0014] The dihydrazide compound is selected from malondihydrazide, succinic dihydrazide, adipamide dihydrazide, isophthalic dihydrazide, o-phthalic dihydrazide or terephthalic dihydrazide.

[0015] The present invention also provides a method for preparing the above-mentioned modified perfluoroelastomer composition, the method comprising the following steps: plasticizing the perfluoroelastomer, adding a dihydrazide compound and magnesium oxide, mixing, rolling, thinning, sheeting, and vulcanizing to obtain the final product.

[0016] Furthermore, the vulcanization conditions are as follows: first, vulcanization is carried out at a pressure of 10-25 MPa and a temperature of 160-200℃ for 5-40 minutes; then, gradient vulcanization is carried out at a temperature of 100-300℃ for 0-48 hours.

[0017] Furthermore, the vulcanization conditions are as follows: first, vulcanize for 10 minutes at a pressure of 16 MPa and a temperature of 170°C; then vulcanize by a gradient increase in temperature of 180°C for 4 hours, 230°C for 8 hours, and 290°C for 8 hours.

[0018] This invention also provides the use of the above-mentioned modified perfluoroelastic composition in the preparation of aerospace and petrochemical materials.

[0019] The present invention has achieved the following beneficial effects:

[0020] Compared to the hydrazide curing system used in patent US8765876B2, the vulcanization time of the modified perfluoroelastic composition of this invention, which uses a dihydrazide compound and magnesium oxide as the curing system, is significantly shortened. Furthermore, this invention also found that adding magnesium oxide to the hydrazide curing system not only effectively increases its vulcanization rate and promotes crosslinking, but also further improves its mechanical properties.

[0021] This invention utilizes dihydrazide compounds and magnesium oxide as a curing system. By controlling the ratio of raw materials, a perfluorinated elastic composition is prepared that can be rapidly vulcanized and also has excellent mechanical properties. It is suitable for commercial production and has broad application prospects in the preparation of seals and gaskets in the aerospace and petrochemical fields.

[0022] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention.

[0023] The above content of the present application is further explained in detail by way of specific embodiments in the form of examples. However, it should not be understood that the scope of the above subject matter of the present application is limited to the following examples. Any technology realized based on the above content of the present application falls within the scope of the present application. DETAILED DESCRIPTION

[0024] The raw materials and equipment used in the present application are known products, which are obtained by purchasing commercially available products.

[0025] The perfluoroether rubber used in the examples and comparative examples is purchased from HALOPOLYMER, Russia, model 1000.

[0026] The method for preparing the perfluoroelastomeric composition in the examples and comparative examples of the present application is as follows:

[0027] S1, Preparation of the rubber compound: first, the perfluoroether rubber is added to a two-roll open mill, plasticized at room temperature, and then all the remaining raw materials in the formula are added, mixed uniformly, and then the roll gap is adjusted to 1 mm or less to wrap the roll, thin triangle bag and roll, and finally the roll gap is adjusted to 2 mm to produce the rubber compound.

[0028] S2, vulcanization: the rubber compound is placed in a mold, and vulcanized at a pressure of 16 MPa and a temperature of 170℃ for 10 min; then two-stage vulcanization is carried out in an oven, with a gradient temperature vulcanization of 180℃ for 4 h, 230℃ for 8 h, and 290℃ for 8 h.

[0029] The room temperature is (25±5℃).

[0030] Example 1

[0031] The perfluoroelastomeric composition is prepared using the following formula: perfluoroether rubber 100 parts, terephthalic dihydrazide 0.5 parts, magnesium oxide 1 part.

[0032] Example 2

[0033] The perfluoroelastomeric composition is prepared using the following formula: perfluoroether rubber 100 parts, m-phenylenedihydrazide 0.5 parts, magnesium oxide 0.2 parts.

[0034] Example 3

[0035] The perfluoroelastomeric composition is prepared using the following formula: perfluoroether rubber 100 parts, adipic dihydrazide 0.5 parts, magnesium oxide 1.5 parts.

[0036] Example 4

[0037] The perfluoroelastomeric composition is prepared using the following formula: perfluoroether rubber 100 parts, malonic dihydrazide 1.2 parts, magnesium oxide 1.8 parts.

[0038] The following comparative examples are used to prepare comparative samples.

[0039] Comparative Example 1

[0040] A perfluoroelastomeric composition was prepared using the following formulation: perfluoroether rubber 100 parts, p-phenylenediamine 0.5 parts.

[0041] Comparative Example 2

[0042] A perfluoroelastomeric composition was prepared using the following formulation: perfluoroether rubber 100 parts, p-phenylenediamine 0.5 parts, phthalamide 0.2 parts.

[0043] Comparative Example 3

[0044] A perfluoroelastomeric composition was prepared using the following formulation: perfluoroether rubber 100 parts, p-phenylenediamine 0.5 parts, zinc oxide 1 part.

[0045] Comparative Example 4

[0046] A perfluoroelastomeric composition was prepared using the following formulation: perfluoroether rubber 100 parts, m-phenylenediamine 0.5 parts.

[0047] Comparative Example 5

[0048] A perfluoroelastomeric composition was prepared using the following formulation: perfluoroether rubber 100 parts, adipic acid dihydrazide 0.5 parts.

[0049] Comparative Example 6

[0050] A perfluoroelastomeric composition was prepared using the following formulation: perfluoroether rubber 100 parts, malonic acid dihydrazide 0.5 parts.

[0051] The beneficial effects of the present application are demonstrated by the following experimental examples.

[0052] Experimental Example 1

[0053] 1. Experimental Method

[0054] The samples of Examples 1-4 and Comparative Examples 1-6 were tested for vulcanization, test standard: GB / T 16584-1996, test conditions: test equipment GT-M3000A, conditions MDR

[0055] 185°C @ 30 min, Arc 0.5.

[0056] Tensile strength, etc. were tested according to the national standard GB / T 528-2009.

[0057] 2. Experimental Results

[0058] The specific experimental results are shown in Tables 1 and 2.

[0059] Table 1: Results of vulcanization test of samples

[0060] Table 1: Results of vulcanization test of samples MH ML TS2 TC90 Example 1 9.69 1.18 1.59 5.22 Example 2 9.74 0.89 1.51 4.55 Example 3 9.21 0.92 1.05 8.12 Example 4 9.92 1.03 0.56 8.45 Comparative Example 1 2.29 0.68 0.00 28.19 Comparative Example 2 9.19 0.61 6.40 16.30 Comparative Example 3 2.71 1.11 0.00 28.11 Comparative Example 4 8.30 0.61 3.49 19:45 Comparative Example 5 7.59 0.72 1.04 26:12 Comparative Example 6 8.01 0.77 0.59 28.07

[0061] ML: minimum torque, N.m (kgf.cm), indicates the flowability of the compound, the lower the ML, the better the flowability, and vice versa.

[0062] MH: maximum torque, N.m (kgf.cm), indicates the crosslinking density of the compound, in general, the lower the MH, the lower the crosslinking density, and the higher the MH, the higher the crosslinking density.

[0063] TS2: the time (min) from the start of the experiment to the curve rising by 0.2 N.m (kgf.cm) from the minimum torque, indicating the operation safety of the compound, the shorter the TS2, the more likely the compound to cause dead material, and the product to produce material defects during production. Conversely, the longer the TS2, the higher the operation safety, but the production efficiency will be lower, and the cost will increase a lot.

[0064] TC90: the time (min) required for the sample to reach a certain degree of vulcanization, mainly used to evaluate the one-time sulfurization conditions of the compound in the molding production, and a longer TC90 indicates a slower vulcanization speed and lower production efficiency.

[0065] Table 2: Mechanical property test results of the samples

[0066]

[0067] Note: Among them, Comparative Examples 1 and 3 are basically in the state of unvulcanized, and cannot be tested for mechanical properties.

[0068] By comparing the vulcanization test results of Examples 1-4 and Comparative Examples 1-6, it can be seen that the addition of magnesium oxide to the hydrazide curing system in Examples 1-4 can effectively improve the vulcanization rate, promote crosslinking, and increase the crosslinking density.

[0069] Further comparison of Examples 1, Comparative Example 2, and Comparative Example 3 shows that in Comparative Example 2, the use of phthalic diamide as a promoter for the hydrazide curing system to promote vulcanization has a weak effect; in Comparative Example 3, the use of zinc oxide, which is also commonly used as an acid absorbent, as a promoter has no vulcanization promoting effect at all; compared with Comparative Examples 2 and 3, the technical scheme of using magnesium oxide as a promoter for the hydrazide curing system in Example 1 of the application significantly improves the vulcanization rate.

[0070] Further comparison of the mechanical properties of Examples 1-4 shows that the tensile strength of the sample obtained by using perfluoroether rubber, terephthalic hydrazide, and magnesium oxide as raw materials in a specific ratio in Example 1 of the application is optimal.

[0071] In conclusion, the application provides a kind of acylhydrazine cured perfluoroelastomer composition, its preparation method and application.The application uses acylhydrazine and magnesium oxide as curing system, and perfluoroelastomer composition is prepared by adjusting the ratio of raw materials.The perfluoroelastomer composition can be quickly vulcanized, has excellent mechanical properties, is suitable for commercial production, and has wide application prospect.

Claims

1. A process for preparing a modified perfluoroelastomeric composition characterized in that, The method comprises the following steps: masticating the perfluoroether rubber, adding diacylhydrazine compound and magnesium oxide, mixing, rolling, thin passing, sheeting, and vulcanizing to obtain the modified perfluoroelastomer composition. The modified perfluoroelastomer composition is prepared from the following raw materials in mass parts: perfluoroether rubber 100 parts, terephthalic dihydrazide 0.5 parts, and magnesium oxide 1 part. The vulcanization conditions are: first vulcanizing at a pressure of 10-25 MPa and a temperature of 160-200 ℃ for 5-40 min; and then gradient vulcanizing at a temperature of 100-300 ℃ for 0-48 h.

2. The method of claim 1, wherein, The vulcanization conditions are: first vulcanizing at a pressure of 16 MPa and a temperature of 170 ℃ for 10 min; and then gradient vulcanizing at 180 ℃ for 4 h, at 230 ℃ for 8 h, and at 290 ℃ for 8 h.

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