A radiation cross-linking sensitizer and its preparation method and application

Abstract

The present invention discloses a radiation cross-linking sensitizer and its preparation method and application. The radiation cross-linking sensitizer of the present invention is obtained by reacting a compound containing multiple carbon-carbon double bonds and a silicone oil containing a silicon-hydrogen bond, and the compound containing multiple carbon-carbon double bonds is at least one of triallyl isocyanurate, trimethylallyl isocyanate, and triallyl cyanurate. The preparation method of the radiation cross-linking sensitizer of the present invention comprises the following steps: a compound containing multiple carbon-carbon double bonds, an inhibitor, and a catalyst are dispersed in a solvent, and then the temperature is raised after adding the silicone oil containing a silicon-hydrogen bond to react, thereby obtaining the radiation cross-linking sensitizer. The radiation cross-linking sensitizer of the present invention has the advantages of high boiling point, good thermal stability, good cross-linking effect, low production cost, etc., can effectively enhance the cross-linking effect of fluoropolymer and reduce the degradation of molecular chain, and its preparation method is simple to operate, and the reaction conditions are mild, and it is suitable for large-scale industrial production and application.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer material processing aids, and in particular to a radiation cross-linking sensitizer, a preparation method and an application thereof. Background Art

[0002] Fluoropolymers contain carbon-carbon bonds and carbon-fluorine bonds (the special electronic structure of fluorine gives it high electronegativity, low polarizability and a small van der Waals radius). Compared with fluorine-free polymers, they have better thermal stability and weather resistance, and lower friction coefficient and surface energy. They are widely used in many fields such as construction, automobiles, aerospace, textiles, energy, microelectronics, biomedicine, etc. Fluoropolymers need to be cross-linked under irradiation to further improve their thermal stability, mechanical properties, dielectric properties and other properties so that they can be better used in harsh environments such as aerospace. However, when fluorine-containing polymers are cross-linked by radiation, the molecular chains will also degrade, which will affect the cross-linking effect of the polymer. Therefore, it is necessary to add a suitable radiation cross-linking sensitizer to improve the cross-linking effect and reduce the degradation of the molecular chains. At present, common radiation cross-linking sensitizers include triallyl isocyanurate (TAIC), trimethylallyl isocyanate (TMAIC), triallyl cyanurate (TAC), etc. The boiling points of these radiation cross-linking sensitizers are all below 200°C, which cannot meet the high-temperature processing environment of fluoropolymers. They are easy to volatilize (produce a large amount of toxic fumes) and self-polymerize during the processing process, and cannot achieve the ideal cross-linking effect.

[0003] Therefore, it is of great significance to develop a radiation cross-linking sensitizer with high boiling point, good thermal stability, good cross-linking effect and low production cost. Summary of the Invention

[0004] The purpose of the present invention is to provide a radiation cross-linking sensitizer and a preparation method and application thereof.

[0005] The technical solution adopted by the present invention is:

[0006] A radiation cross-linking sensitizer is obtained by reacting a compound containing multiple carbon-carbon double bonds with silicone oil containing silicon-hydrogen bonds; the compound containing multiple carbon-carbon double bonds is at least one of triallyl isocyanurate (TAIC), trimethallyl isocyanate (TMAIC), and triallyl cyanurate (TAC).

[0007] Preferably, the molar ratio of carbon-carbon double bonds in the compound containing multiple carbon-carbon double bonds to silicon-hydrogen bonds in the silicone oil containing silicon-hydrogen bonds is 1 to 6:1.

[0008] Preferably, the hydrogen content of the silicone oil containing silicon-hydrogen bonds is less than 2 wt %.

[0009] A method for preparing the radiation cross-linking sensitizer as described above comprises the following steps:

[0010] A compound containing multiple carbon-carbon double bonds, an inhibitor and a catalyst are dispersed in a solvent, and then silicone oil containing silicon-hydrogen bonds is added and the temperature is raised to react to obtain a radiation cross-linking sensitizer.

[0011] Preferably, the amount of the inhibitor is 0.2% to 1.5% by weight of the silicone oil containing silicon-hydrogen bonds.

[0012] Preferably, the inhibitor is at least one of 1-ethynylcyclohexanol, 2-vinylisopropanol, and 1-ethynylcyclopentanol.

[0013] Preferably, the amount of the catalyst used is 0.2% to 2% by weight of the silicone oil containing silicon-hydrogen bonds.

[0014] Preferably, the catalyst is at least one of Custer catalyst, platinum phosphate, and chloroplatinic acid.

[0015] Preferably, the solvent is at least one of toluene and xylene.

[0016] Preferably, the reaction is carried out at a temperature of 70° C. to 110° C., and the reaction time is 2 h to 10 h.

[0017] More preferably, the reaction is carried out at a temperature of 90° C. to 110° C., and the reaction time is 2 h to 4 h.

[0018] Preferably, the reaction is carried out at a stirring speed of 80 r / min to 180 r / min.

[0019] More preferably, the reaction is carried out at a stirring speed of 100 r / min to 150 r / min.

[0020] Preferably, after the reaction is completed, the product is further subjected to ethanol extraction and column chromatography purification.

[0021] A fluoropolymer product comprising the radiation cross-linking sensitizer.

[0022] Preferably, the weight ratio of the fluoropolymer to the radiation cross-linking sensitizer in the fluoropolymer product is 100:0.05-20.

[0023] A method for preparing the fluoropolymer article as described above comprises the following steps:

[0024] The fluorine-containing polymer and the radiation cross-linking sensitizer are mixed and subjected to extrusion molding or injection molding, and then subjected to radiation cross-linking to obtain the fluorine-containing polymer product.

[0025] Preferably, the radiation cross-linking is performed at a radiation dose of 10 Mrad to 120 Mrad.

[0026] Preferably, the product is annealed after the radiation cross-linking is completed.

[0027] Preferably, the annealing is performed at a temperature of 100° C. to 130° C., and the annealing time is 1 hour to 3 hours.

[0028] The beneficial effects of the present invention are as follows: the radiation cross-linking sensitizer of the present invention has the advantages of high boiling point, good thermal stability, good cross-linking auxiliary effect, low production cost, etc., can effectively improve the cross-linking effect of fluorine-containing polymers and reduce the degradation of molecular chains, and its preparation method is simple to operate and the reaction conditions are mild, and it is suitable for large-scale industrial production and application.

[0029] Specifically:

[0030] 1) The radiation cross-linking sensitizer of the present invention is a long-chain macromolecule, and the cross-linked network structure formed in the fluoropolymer can effectively improve the mechanical properties of the fluoropolymer;

[0031] 2) The radiation cross-linking sensitizer of the present invention is liquid at room temperature, has a boiling point above 250°C, has excellent thermal stability, and is not prone to self-polymerization. It can meet the processing and modification requirements of most fluoropolymers. During the processing, the liquid radiation cross-linking sensitizer can also act as a plasticizer for the fluoropolymer, thereby effectively improving the processing properties of the fluoropolymer.

[0032] 3) The preparation process of the radiation cross-linking sensitizer of the present invention is simple to operate, low in cost, and has mild reaction conditions. It can be prepared quickly and in large quantities, and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the FTIR graph of the radiation cross-linking sensitizer in Example 1.

[0034] Figure 2 This is the FTIR graph of the radiation cross-linking sensitizer in Example 2.

[0035] Figure 3 This is the FTIR graph of the radiation cross-linking sensitizer in Example 3.

[0036] Figure 4 This is the FTIR graph of the radiation cross-linking sensitizer in Example 4.

[0037] Figure 5 This is the FTIR graph of the radiation cross-linking sensitizer in Example 5.

[0038] Figure 6This is the FTIR graph of the radiation cross-linking sensitizer in Example 6.

[0039] Figure 7 This is the FTIR graph of the radiation cross-linking sensitizer in Example 7. DETAILED DESCRIPTION

[0040] The present invention will be further explained and illustrated below with reference to specific embodiments.

[0041] Example 1:

[0042] A radiation cross-linking sensitizer, the preparation method of which is as follows:

[0043] 20 g of triallyl isocyanurate (TAIC) and 0.2 g of 1-ethynylcyclohexanol were mixed and stirred evenly, and then 0.2 g of Custer catalyst (PT-5000 of Guangzhou Xiyi Chemical Co., Ltd.) and 60 mL of toluene were added and stirred evenly, and then 10 g of silicon-hydrogen bond-containing silicone oil with a hydrogen content of 0.8 wt% (DFH-08 of Guangzhou Jibisheng Technology Industrial Co., Ltd.) was added and stirred evenly, and then heated to 100 ° C and stirred for 4 h at a stirring speed of 100 r / min. The mixture was naturally cooled to room temperature, and then unreacted triallyl isocyanurate and toluene in the product were removed by ethanol extraction, and then column chromatography was performed on a silica gel column to remove the Custer catalyst. The eluent used for column chromatography was methanol, and then vacuum distillation was performed to obtain an irradiation cross-linking sensitizer.

[0044] The Fourier transform infrared spectrum (FTIR) of the radiation cross-linking sensitizer in this embodiment is shown in FIG. Figure 1 shown.

[0045] Depend on Figure 1 It can be seen that TAIC successfully reacted with silicone oil containing silicon-hydrogen bonds, and the corresponding carbon-carbon double bond characteristic peaks and silicon-hydrogen bond characteristic peaks appeared at the same time.

[0046] According to tests, the boiling point of the radiation cross-linking sensitizer in this embodiment is 304°C.

[0047] A fluoropolymer product (standard sample), the preparation method of which is as follows:

[0048] The fluoropolymer EP-521 of Shanghai Jinfu Chemical Technology Co., Ltd. and the radiation cross-linking sensitizer in this embodiment were added to a twin-screw extruder in a weight ratio of 100:4 for extrusion granulation. During the extrusion process, the temperatures of barrel zone 1, barrel zone 2, barrel zone 3, barrel zone 4, barrel zone 5, barrel zone 6, barrel zone 7, barrel zone 8 and die zone of the extruder were set to 260°C, 265°C, 265°C, 265°C, 270°C, 275°C, 280°C, 280°C and 285°C, respectively, the speed of the main screw was set to 120 rpm, and the speed of the feeder screw was set to 30 rpm. The extruded pellets were placed in a flat vulcanizer at 280°C and pressed into standard specimens, which were then subjected to electron irradiation for 5 minutes at a radiation dose of 15 Mrad to obtain fluoropolymer products.

[0049] Example 2:

[0050] A radiation cross-linking sensitizer is prepared in the same manner as in Example 1, except that the amount of triallyl isocyanurate is adjusted from 20 g to 30 g.

[0051] The FTIR spectrum of the radiation cross-linking sensitizer in this example is as follows: Figure 2 shown.

[0052] Depend on Figure 2 It can be seen that TAIC successfully reacted with silicone oil containing silicon-hydrogen bonds, and the corresponding carbon-carbon double bond characteristic peaks and silicon-hydrogen bond characteristic peaks appeared at the same time.

[0053] According to tests, the boiling point of the radiation cross-linking sensitizer in this embodiment is 318° C., which is higher than that in Example 1. The reason is that the increased amount of TAIC promotes its reaction with silicone oil containing silicon-hydrogen bonds.

[0054] A fluorine-containing polymer product is identical to Example 1 except that the weight of the radiation cross-linking sensitizer is replaced by the radiation cross-linking sensitizer in this example during preparation.

[0055] Example 3:

[0056] A radiation cross-linking sensitizer is prepared in the same manner as in Example 1, except that the amount of triallyl isocyanurate is adjusted from 20 g to 10 g.

[0057] The FTIR spectrum of the radiation cross-linking sensitizer in this example is as follows: Figure 3 shown.

[0058] Depend on Figure 3 It can be seen that TAIC successfully reacted with silicone oil containing silicon-hydrogen bonds, and the corresponding carbon-carbon double bond characteristic peaks and silicon-hydrogen bond characteristic peaks appeared at the same time.

[0059] According to the test, the boiling point of the radiation cross-linking sensitizer in this embodiment is 293° C., which is lower than that in Example 1. The reason is that the amount of TAIC used is reduced, which weakens its reaction with the silicone oil containing silicon-hydrogen bonds.

[0060] A fluorine-containing polymer product is identical to Example 1 except that the weight of the radiation cross-linking sensitizer is replaced by the radiation cross-linking sensitizer in this example during preparation.

[0061] Example 4:

[0062] A radiation cross-linking sensitizer is prepared in the same manner as in Example 1 except that the amount of the Custer catalyst is adjusted from 0.2 g to 0.4 g.

[0063] The FTIR spectrum of the radiation cross-linking sensitizer in this example is as follows: Figure 4 shown.

[0064] Depend on Figure 4 It can be seen that TAIC successfully reacted with silicone oil containing silicon-hydrogen bonds, and the corresponding carbon-carbon double bond characteristic peaks and silicon-hydrogen bond characteristic peaks appeared at the same time.

[0065] According to the test, the boiling point of the radiation cross-linking sensitizer in this embodiment is 313° C., which is higher than that in Example 1. The reason is that the increase in the amount of Custer catalyst promotes the reaction between TAIC and silicone oil containing silicon-hydrogen bonds.

[0066] A fluorine-containing polymer product is identical to Example 1 except that the weight of the radiation cross-linking sensitizer is replaced by the radiation cross-linking sensitizer in this example during preparation.

[0067] Example 5:

[0068] A radiation cross-linking sensitizer is prepared in the same manner as in Example 1, except that the amount of 1-ethynylcyclohexanol used is adjusted from 0.2 g to 0.4 g.

[0069] The FTIR spectrum of the radiation cross-linking sensitizer in this example is as follows: Figure 5 shown.

[0070] Depend on Figure 5 It can be seen that TAIC successfully reacted with silicone oil containing silicon-hydrogen bonds, and the corresponding carbon-carbon double bond characteristic peaks and silicon-hydrogen bond characteristic peaks appeared at the same time.

[0071] After testing, the boiling point of the radiation cross-linking sensitizer in this embodiment is 302° C., which is close to that of the radiation cross-linking sensitizer in Example 1. This indicates that 1-ethynylcyclohexanol is almost completely volatilized during the heating process and does not affect the boiling point of the radiation cross-linking sensitizer.

[0072] A fluorine-containing polymer product is identical to Example 1 except that the weight of the radiation cross-linking sensitizer is replaced by the radiation cross-linking sensitizer in this example during preparation.

[0073] Example 6:

[0074] A radiation cross-linking sensitizer is prepared in the same manner as in Example 1, except that the stirring speed is adjusted from 100 r / min to 180 r / min.

[0075] The FTIR spectrum of the radiation cross-linking sensitizer in this example is as follows: Figure 6 shown.

[0076] Depend on Figure 6 It can be seen that TAIC successfully reacted with silicone oil containing silicon-hydrogen bonds, and the corresponding carbon-carbon double bond characteristic peaks and silicon-hydrogen bond characteristic peaks appeared at the same time.

[0077] According to tests, the boiling point of the radiation cross-linking sensitizer in this embodiment is 295° C., which is lower than that of the radiation cross-linking sensitizer in Example 1. The reason is that the stirring speed is too fast, which weakens the reaction between TAIC and silicone oil containing silicon-hydrogen bonds.

[0078] A fluorine-containing polymer product is identical to Example 1 except that the weight of the radiation cross-linking sensitizer is replaced by the radiation cross-linking sensitizer in this example during preparation.

[0079] Example 7:

[0080] A radiation cross-linking sensitizer is prepared in the same manner as in Example 1 except that the reaction time is adjusted from 4 hours to 7 hours.

[0081] The FTIR spectrum of the radiation cross-linking sensitizer in this example is as follows: Figure 7 shown.

[0082] Depend on Figure 7 It can be seen that TAIC successfully reacted with silicone oil containing silicon-hydrogen bonds, and the corresponding carbon-carbon double bond characteristic peaks and silicon-hydrogen bond characteristic peaks appeared at the same time.

[0083] According to tests, the boiling point of the radiation cross-linking sensitizer in this embodiment is 322° C., which is higher than that of the radiation cross-linking sensitizer in Example 1. The reason is that the reaction time is prolonged and the reaction degree of TAIC with the silicone oil containing silicon-hydrogen bonds is higher.

[0084] A fluorine-containing polymer product is identical to Example 1 except that the weight of the radiation cross-linking sensitizer is replaced by the radiation cross-linking sensitizer in this example during preparation.

[0085] Comparative Example 1:

[0086] A fluoropolymer product is prepared in the same manner as in Example 1 except that no radiation cross-linking sensitizer is added during preparation.

[0087] Comparative Example 2:

[0088] A fluoropolymer product is prepared in the same manner as in Example 1 except that the weight of the radiation cross-linking sensitizer is replaced by TAIC (Hunan Minhe Chemical Co., Ltd., model number FARIDA TAICS).

[0089] Comparative Example 3:

[0090] A fluoropolymer product is prepared in the same manner as in Example 1, except that the weight of the radiation crosslinking sensitizer is replaced by TAIC and silicone oil containing Si-H bonds (same as in Example 1; the weight ratio of TAIC to silicone oil containing Si-H bonds is 2:1). Performance test:

[0091] The mechanical property test results of the fluoropolymer products in Examples 1 to 7 and Comparative Examples 1 to 3 are shown in the following table:

[0092] Table 1 Mechanical properties test results of fluoropolymer products in Examples 1 to 7 and Comparative Examples 1 to 3

[0093]

[0094] Note:

[0095] Tensile strength and elongation at break: tested with reference to “ASTM D638 Standard Test Method for Tensile Properties of Plastics”, with a tensile speed of 50 mm / min and a test temperature of 25°C.

[0096] From Table 1 we can see that:

[0097] 1) The mechanical properties of the fluoropolymer products in Examples 1-7 were significantly improved compared to the fluoropolymer products in Comparative Examples 1-3 (the tensile strength of the fluoropolymer product in Example 4 was as high as 53.4 MPa). This is because the radiation cross-linking sensitizers in Examples 1-7 were essentially non-volatile during processing and were not prone to self-polymerization. They could be effectively mixed into the fluoropolymer and effectively promoted cross-linking during irradiation. The radiation cross-linking reaction was much higher than the radiation degradation reaction, thus enabling the fluoropolymer products to achieve ideal mechanical properties.

[0098] 2) In Comparative Example 1, the fluoropolymer was directly extruded and irradiated without a radiation cross-linking sensitizer to promote cross-linking during the irradiation process. The fluoropolymer underwent significant degradation during the irradiation process, which reduced the mechanical properties of the fluoropolymer product.

[0099] 3) In Comparative Example 2, unmodified TAIC was added. During processing, a large amount of TAIC self-polymerized and volatilized. The mechanical properties of the fluoropolymer were not substantially improved after irradiation.

[0100] 4) In Comparative Example 3, TAIC and a silicone oil containing Si-H bonds were directly mixed with a fluoropolymer to form pellets. After processing and irradiation, the mechanical properties of the fluoropolymer product were also less than ideal. This is because there was no suitable reaction environment during processing for the TAIC and the silicone oil containing Si-H bonds to react. Therefore, it was impossible to achieve the same effect as the irradiation crosslinking sensitizer in Examples 1 to 7.

[0101] In summary, the radiation cross-linking sensitizer of the present invention has the advantages of high boiling point, good thermal stability, good cross-linking effect, and low production cost. It can effectively enhance the cross-linking effect of fluorinated polymers and reduce the degradation of molecular chains. In addition, its preparation method is simple to operate and the reaction conditions are mild, making it suitable for large-scale industrial production and application.

[0102] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A fluoropolymer product, characterized in that The invention comprises a radiation cross-linking sensitizer; the radiation cross-linking sensitizer is obtained by reacting a compound containing multiple carbon-carbon double bonds and a silicone oil containing silicon-hydrogen bonds; the compound containing multiple carbon-carbon double bonds is at least one of triallyl isocyanurate, trimethallyl isocyanate, and triallyl cyanurate; the molar ratio of the carbon-carbon double bonds in the compound containing multiple carbon-carbon double bonds to the silicon-hydrogen bonds in the silicone oil containing silicon-hydrogen bonds is 1 to 6:1; the weight ratio of the fluoropolymer to the radiation cross-linking sensitizer in the fluoropolymer product is 100:0.05 to 20.

2. The fluoropolymer article according to claim 1, wherein: The hydrogen content of the silicone oil containing silicon-hydrogen bonds is less than 2 wt %.

3. The fluoropolymer article according to claim 1, wherein: The radiation cross-linking sensitizer is prepared by a preparation method comprising the following steps: dispersing a compound containing multiple carbon-carbon double bonds, an inhibitor and a catalyst in a solvent, adding silicone oil containing silicon-hydrogen bonds, and heating the solvent for reaction to obtain the radiation cross-linking sensitizer.

4. The fluoropolymer article according to claim 3, wherein: The amount of the inhibitor is 0.2% to 1.5% of the weight of the silicone oil containing silicon-hydrogen bonds; the amount of the catalyst is 0.2% to 2% of the weight of the silicone oil containing silicon-hydrogen bonds.

5. The fluoropolymer article according to claim 3 or 4, characterized in that: The inhibitor is at least one of 1-ethynylcyclohexanol, 2-vinyl isopropanol, and 1-ethynylcyclopentanol; and the catalyst is at least one of Custer catalyst, platinum phosphate, and chloroplatinic acid.

6. The fluoropolymer article according to claim 3 or 4, characterized in that: The reaction is carried out at a temperature of 70° C. to 110° C., and the reaction time is 2 h to 10 h.

7. The fluoropolymer article according to claim 3 or 4, characterized in that: After the reaction is completed, the product is extracted with ethanol and purified by column chromatography.

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