A high-toughness pressure-resistant composite plastic and its preparation process

Abstract

The invention relates to the technical field of polypropylene, and discloses a high-toughness pressure-resistant composite plastic and a preparation process thereof. The invention uses pyromellitic anhydride as a central core to react with diallylamine to obtain pyromellitic tetraallylamine, and then uses mercaptopropyltriethoxysilane to modify nano titanium dioxide to synthesize multi-nanometer titanium dioxide dendron compounds, uses multi-nanometer titanium dioxide dendron compounds as a dispersed phase, and uses polypropylene as a matrix to melt blend to prepare a high-toughness pressure-resistant composite plastic. The invention uses multi-nanometer titanium dioxide dendron compounds as a dispersed phase, disperses them in polypropylene, and utilizes the nano titanium dioxide and a large number of branched structures contained therein to enhance the toughness and pressure resistance of polypropylene plastics. The composite plastic prepared by the invention has high toughness and pressure resistance.

Description

Technical Field

[0001] The invention relates to the technical field of polypropylene, in particular to a high-toughness pressure-resistant composite plastic and a preparation process thereof. Background Art

[0002] Polypropylene has the advantages of abundant sources, low prices, and easy molding and processing. Its products have good gloss, are non-toxic and odorless. Therefore, it is widely used in household daily necessities, home appliances, packaging and other fields. However, in actual applications, due to its poor toughness and poor pressure resistance, this greatly limits the further promotion and application of polypropylene.

[0003] Nanomaterials have attracted widespread attention from many scientists due to their important application value and broad development prospects. Nano titanium dioxide is a type of nanomaterial. Due to its excellent antibacterial properties, thermal stability, chemical stability and other properties, it is widely used in anti-ultraviolet materials, coatings, packaging materials and other fields.

[0004] For example, the patent with the authorization announcement number CN 103059405 B discloses an antibacterial polypropylene plastic, which uses polypropylene, nano-titanium dioxide, etc. as raw materials to prepare an antibacterial polypropylene plastic that has strong antibacterial and anti-mildew effects. However, it does not improve the toughness and pressure resistance of polypropylene plastic. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] In view of the deficiencies in the prior art, the present invention provides a high-toughness and pressure-resistant composite plastic and a preparation process thereof. The prepared composite plastic has high toughness and pressure resistance.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A high-toughness pressure-resistant composite plastic comprises the following raw materials, measured by weight: 100 parts of polypropylene and 1-5 parts of multi-nanometer titanium dioxide dendritic compounds.

[0009] Furthermore, the high-toughness pressure-resistant composite plastic is prepared by the following process:

[0010] Polypropylene and multi-nano titanium dioxide dendritic compound are added into a high-speed mixer and mixed evenly, melt-extruded from a twin-screw extruder, pelletized, dried, and placed in an injection molding machine for injection molding to obtain a high-toughness and pressure-resistant composite plastic.

[0011] Furthermore, the temperatures of the three zones of the extruder are 180°C, 185°C, and 185°C, and the head temperature is 215°C.

[0012] Furthermore, the injection molding temperature is three stages of 190° C., 180° C., and 160° C., and the injection pressure is 7 MPa.

[0013] Furthermore, the preparation process of the multi-nano titanium dioxide dendritic compound is as follows:

[0014] (1) Preparation process of tetraallylamine

[0015] Under a nitrogen atmosphere, diallylamine is added to an N,N-dimethylformamide solvent, stirred and dispersed, and then a N,N-dimethylformamide solution of pyromellitic anhydride is added thereto. The reaction is carried out at room temperature for 2-5 hours. After the reaction is completed, toluene is used for precipitation, washing, filtering and drying to obtain pyromellitic anhydride tetraallylamine.

[0016] (2) Preparation process of mercaptopropyltriethoxysilane modified nano-titanium dioxide

[0017] Add nano silicon dioxide to 90% by mass ethanol aqueous solution, stir and disperse, use glacial acetic acid to adjust the pH to 3-4, and ultrasonically disperse in a 100W ultrasonic cleaner for 1-3 hours. After the dispersion, add mercaptopropyl triethoxysilane at 75-85°C, stir and react for 5-8 hours. After the dispersion, filter, wash, dry, extract with tetrahydrofuran, and dry to obtain mercaptopropyl triethoxysilane modified nano titanium dioxide.

[0018] (3) Preparation process of multi-nano titanium dioxide dendrimer compounds

[0019] Add mercaptopropyl triethoxysilane modified nano titanium dioxide into N,N-dimethylformamide solvent, ultrasonically disperse in a 100W ultrasonic cleaner for 1-2 hours, then add tetraallylamine and initiator, stir and mix evenly, initiate reaction under ultraviolet light for 20-50 minutes, filter, wash, dry, extract with tetrahydrofuran, and dry to obtain multi-nanometer titanium dioxide dendritic compound.

[0020] Furthermore, in (1), the usage ratio of diallylamine to pyromellitic anhydride is (1.8-2.5) g:1 g.

[0021] Furthermore, in (2), the usage ratio of nano-silicon dioxide and mercaptopropyltriethoxysilane is 1g:(0.1-0.4)g.

[0022] Furthermore, in (3), the usage ratio of mercaptopropyl triethoxysilane modified nano titanium dioxide, pyromellitic acid tetraallylamine, and initiator is 1g:(0.05-0.2)g:(0.004-0.01)g.

[0023] Furthermore, in (3), the initiator is one of photoinitiator 907 and 2-methoxy-2-phenylacetophenone.

[0024] (III) Beneficial technical effects

[0025] The invention uses pyromellitic anhydride as a central core to react with diallylamine to obtain pyromellitic tetraallylamine, and then uses mercaptopropyltriethoxysilane to modify nano titanium dioxide to synthesize multi-nanometer titanium dioxide dendritic compounds. The preparation method is simple and the structure is novel. Then, the multi-nanometer titanium dioxide dendritic compounds are used as dispersed phases and polypropylene is used as a matrix for melt blending to prepare high-toughness and pressure-resistant composite plastics.

[0026] The nano titanium dioxide used in the present invention has a large surface energy and is therefore easy to agglomerate. The present invention makes it organic, enhances its compatibility with organic substances, and uniformly disperses it in the material. This inorganic interface can not only transmit loads, thereby enhancing the material's ability to absorb external energy and resist crack expansion, thereby showing increased strength, but also the inorganic nanoparticles can change the stress field and stress concentration in the material matrix. When the material is stretched by an external force, the two ends of the inorganic particles are subjected to the tensile stress of the material, while the middle is subjected to compressive stress. Due to the interaction of forces, it is conducive to the occurrence of yielding, showing increased toughness. Therefore, the addition of nano titanium dioxide can improve the toughness and pressure resistance of plastics.

[0027] In addition, the present invention uses multi-nano titanium dioxide dendritic compounds as dispersed phases and disperses them in polypropylene. Since they contain more branched structures, when added to polypropylene, they can be entangled with each other to form more cross-linking sites. When subjected to external pressure and tension, these external energies can be dispersed along the cross-linking sites to other branches, further improving the toughness and pressure resistance of the material. The composite plastic prepared by the present invention has higher toughness and excellent pressure resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the reaction process of tetraallylamine.

[0029] Figure 2 It is the reaction process of modifying nano titanium dioxide with mercaptopropyltriethoxysilane.

[0030] Figure 3 It is the reaction process of multi-nano titanium dioxide dendritic compounds. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] (1) Preparation process of tetraallylamine

[0034] Under a nitrogen atmosphere, 4 g of diallylamine was added to an N,N-dimethylformamide solvent and stirred for dispersion. Then, an N,N-dimethylformamide solution containing 2.2 g of pyromellitic anhydride was added thereto. The mixture was reacted for 5 h at room temperature. After the reaction was completed, toluene was used for precipitation, washing, filtering and drying to obtain pyromellitic anhydride tetraallylamine.

[0035] (2) Preparation process of mercaptopropyltriethoxysilane modified nano-titanium dioxide

[0036] Add 5 g of nano-silicon dioxide to a 90% by mass ethanol aqueous solution, stir and disperse, use glacial acetic acid to adjust the pH to 4, and ultrasonically disperse in a 100 W ultrasonic cleaner for 2 hours. After the dispersion, add 0.5 g of mercaptopropyltriethoxysilane at 80°C and stir to react for 6 hours. After the dispersion, filter, wash, dry, extract with tetrahydrofuran, and dry to obtain mercaptopropyltriethoxysilane-modified nano-titanium dioxide.

[0037] (3) Preparation process of multi-nano titanium dioxide dendrimer compounds

[0038] 4 g of mercaptopropyl triethoxysilane-modified nano titanium dioxide was added to N,N-dimethylformamide solvent, and ultrasonically dispersed in a 100 W ultrasonic cleaner for 2 h. Then, 0.2 g of tetraallylamine and 0.02 g of initiator 907 were added thereto, and the mixture was stirred and mixed evenly. The reaction was initiated under ultraviolet light for 30 min, and the mixture was filtered, washed, dried, extracted with tetrahydrofuran, and dried to obtain a multi-nanometer titanium dioxide dendritic compound.

[0039] (4) Preparation process of high-toughness and pressure-resistant composite plastics

[0040] 100g of polypropylene and 1g of multi-nano titanium dioxide dendritic compound are added to a high-speed mixer and mixed evenly, and then melt-extruded from a twin-screw extruder with the temperatures of the three zones of the extruder being 180°C, 185°C, and 185°C, and the head temperature being 215°C. The pellets are cut into pellets, dried, and placed in an injection molding machine for injection molding with the three-stage injection molding temperatures being 190°C, 180°C, and 160°C, and the injection pressure being 7MPa, to obtain a high-toughness and pressure-resistant composite plastic.

[0041] Example 2

[0042] (1) Preparation process of tetraallylamine

[0043] Under a nitrogen atmosphere, 4.5 g of diallylamine was added to an N,N-dimethylformamide solvent and stirred for dispersion. Then, an N,N-dimethylformamide solution containing 2.2 g of pyromellitic anhydride was added thereto. The mixture was reacted for 4 h at room temperature. After the reaction was completed, toluene was used for precipitation, washing, filtering and drying to obtain pyromellitic anhydride tetraallylamine.

[0044] (2) Preparation process of mercaptopropyltriethoxysilane modified nano-titanium dioxide

[0045] Add 5 g of nano-silicon dioxide to a 90% by mass ethanol aqueous solution, stir and disperse, use glacial acetic acid to adjust the pH to 3, and ultrasonically disperse in a 100 W ultrasonic cleaner for 2 hours. After the dispersion, add 1 g of mercaptopropyltriethoxysilane at 85°C and stir to react for 5 hours. After the dispersion, filter, wash, dry, extract with tetrahydrofuran, and dry to obtain mercaptopropyltriethoxysilane-modified nano-titanium dioxide.

[0046] (3) Preparation process of multi-nano titanium dioxide dendrimer compounds

[0047] 4 g of mercaptopropyl triethoxysilane-modified nano titanium dioxide was added to N,N-dimethylformamide solvent, and ultrasonically dispersed in a 100 W ultrasonic cleaner for 1 h. Then, 0.5 g of tetraallylamine and 0.016 g of 2-methoxy-2-phenylacetophenone initiator were added thereto, and the mixture was stirred and mixed evenly. The reaction was initiated under ultraviolet light for 50 min, and the mixture was filtered, washed, dried, extracted with tetrahydrofuran, and dried to obtain a multi-nanometer titanium dioxide dendritic compound.

[0048] (4) Preparation process of high-toughness and pressure-resistant composite plastics

[0049] 100 g of polypropylene and 2 g of multi-nano titanium dioxide dendritic compound are added to a high-speed mixer and mixed evenly, and then melt-extruded from a twin-screw extruder with the temperatures of the three zones of the extruder being 180° C., 185° C., and 185° C., and the head temperature being 215° C., pelletized, dried, and placed in an injection molding machine for injection molding with the three-stage injection molding temperatures being 190° C., 180° C., and 160° C. and the injection pressure being 7 MPa to obtain a high-toughness, pressure-resistant composite plastic.

[0050] Example 3

[0051] (1) Preparation process of tetraallylamine

[0052] Under a nitrogen atmosphere, 5.5 g of diallylamine was added to an N,N-dimethylformamide solvent and stirred for dispersion. Then, an N,N-dimethylformamide solution containing 2.2 g of pyromellitic anhydride was added thereto. The mixture was reacted for 2 h at room temperature. After the reaction was completed, toluene was used for precipitation, washing, filtering and drying to obtain pyromellitic anhydride tetraallylamine.

[0053] (2) Preparation process of mercaptopropyltriethoxysilane modified nano-titanium dioxide

[0054] Add 5 g of nano-silicon dioxide to a 90% by mass ethanol aqueous solution, stir and disperse, use glacial acetic acid to adjust the pH to 4, and ultrasonically disperse in a 100 W ultrasonic cleaner for 2 hours. After the dispersion, add 1.5 g of mercaptopropyltriethoxysilane at 80°C and stir to react for 6 hours. After the dispersion, filter, wash, dry, extract with tetrahydrofuran, and dry to obtain mercaptopropyltriethoxysilane-modified nano-titanium dioxide.

[0055] (3) Preparation process of multi-nano titanium dioxide dendrimer compounds

[0056] 4 g of mercaptopropyl triethoxysilane-modified nano titanium dioxide was added to N,N-dimethylformamide solvent, and ultrasonically dispersed in a 100 W ultrasonic cleaner for 2 h. Then, 0.8 g of tetraallylamine and 0.04 g of 2-methoxy-2-phenylacetophenone initiator were added thereto, and the mixture was stirred and mixed evenly. The reaction was initiated under ultraviolet light for 20 min, and the mixture was filtered, washed, dried, extracted with tetrahydrofuran, and dried to obtain a multi-nanometer titanium dioxide dendritic compound.

[0057] (4) Preparation process of high-toughness and pressure-resistant composite plastics

[0058] 100 g of polypropylene and 3 g of multi-nano titanium dioxide dendritic compound are added to a high-speed mixer and mixed evenly, and then melt-extruded from a twin-screw extruder with the temperatures of the three zones of the extruder being 180° C., 185° C., and 185° C., and the head temperature being 215° C., pelletized, dried, and placed in an injection molding machine for injection molding with the three-stage injection molding temperatures being 190° C., 180° C., and 160° C. and the injection pressure being 7 MPa to obtain a high-toughness and pressure-resistant composite plastic.

[0059] Example 4

[0060] (1) Preparation process of tetraallylamine

[0061] Under a nitrogen atmosphere, 4.5 g of diallylamine was added to an N,N-dimethylformamide solvent and stirred for dispersion. Then, an N,N-dimethylformamide solution containing 2.2 g of pyromellitic anhydride was added thereto. The mixture was reacted for 5 h at room temperature. After the reaction was completed, toluene was used for precipitation, washing, filtering and drying to obtain pyromellitic anhydride tetraallylamine.

[0062] (2) Preparation process of mercaptopropyltriethoxysilane modified nano-titanium dioxide

[0063] Add 5 g of nano-silica to a 90% by mass ethanol aqueous solution, stir and disperse, use glacial acetic acid to adjust the pH to 3, and ultrasonically disperse in a 100 W ultrasonic cleaner for 3 hours. After the dispersion, add 1.8 g of mercaptopropyltriethoxysilane at 75°C and stir to react for 8 hours. After the dispersion, filter, wash, dry, extract with tetrahydrofuran, and dry to obtain mercaptopropyltriethoxysilane-modified nano-titanium dioxide.

[0064] (3) Preparation process of multi-nano titanium dioxide dendrimer compounds

[0065] 4 g of mercaptopropyl triethoxysilane-modified nano titanium dioxide was added to N,N-dimethylformamide solvent, and ultrasonically dispersed in a 100 W ultrasonic cleaner for 1 h. Then, 0.5 g of tetraallylamine and 0.03 g of initiator 907 were added thereto, and the mixture was stirred and mixed evenly. The reaction was initiated under ultraviolet light for 40 min, and the mixture was filtered, washed, dried, extracted with tetrahydrofuran, and dried to obtain a multi-nanometer titanium dioxide dendritic compound.

[0066] (4) Preparation process of high-toughness and pressure-resistant composite plastics

[0067] 100 g of polypropylene and 4 g of multi-nano titanium dioxide dendritic compound are added to a high-speed mixer and mixed evenly, and then melt-extruded from a twin-screw extruder with the temperatures of the three zones of the extruder being 180° C., 185° C., and 185° C., and the head temperature being 215° C., pelletized, dried, and placed in an injection molding machine for injection molding with the three-stage injection molding temperatures being 190° C., 180° C., and 160° C. and the injection pressure being 7 MPa to obtain a high-toughness, pressure-resistant composite plastic.

[0068] Example 5

[0069] (1) Preparation process of tetraallylamine

[0070] Under a nitrogen atmosphere, 5.5 g of diallylamine was added to an N,N-dimethylformamide solvent and stirred for dispersion. Then, an N,N-dimethylformamide solution containing 2.2 g of pyromellitic anhydride was added thereto. The mixture was reacted for 4 h at room temperature. After the reaction, toluene was used for precipitation, washing, filtering and drying to obtain pyromellitic anhydride tetraallylamine.

[0071] (2) Preparation process of mercaptopropyltriethoxysilane modified nano-titanium dioxide

[0072] Add 5 g of nano-silicon dioxide to a 90% by mass ethanol aqueous solution, stir and disperse, use glacial acetic acid to adjust the pH to 3, and ultrasonically disperse in a 100 W ultrasonic cleaner for 1 hour. After the dispersion, add 2 g of mercaptopropyltriethoxysilane at 85°C and stir to react for 5 hours. After the dispersion, filter, wash, dry, extract with tetrahydrofuran, and dry to obtain mercaptopropyltriethoxysilane-modified nano-titanium dioxide.

[0073] (3) Preparation process of multi-nano titanium dioxide dendrimer compounds

[0074] 4 g of mercaptopropyl triethoxysilane-modified nano titanium dioxide was added to N,N-dimethylformamide solvent, and ultrasonically dispersed in a 100 W ultrasonic cleaner for 2 h. Then, 0.6 g of tetraallylamine and 0.02 g of initiator 907 were added thereto, and the mixture was stirred and mixed evenly. The reaction was initiated under ultraviolet light for 40 min, and the mixture was filtered, washed, dried, extracted with tetrahydrofuran, and dried to obtain a multi-nanometer titanium dioxide dendritic compound.

[0075] (4) Preparation process of high-toughness and pressure-resistant composite plastics

[0076] 100 g of polypropylene and 5 g of multi-nano titanium dioxide dendritic compound are added to a high-speed mixer and mixed evenly, and then melt-extruded from a twin-screw extruder with the temperatures of the three zones of the extruder being 180° C., 185° C., and 185° C., and the head temperature being 215° C., pelletized, dried, and placed in an injection molding machine for injection molding with the three-stage injection molding temperatures being 190° C., 180° C., and 160° C. and the injection pressure being 7 MPa to obtain a high-toughness and pressure-resistant composite plastic.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 1 is that in step (4), nano-titanium dioxide modified with mercaptopropyltriethoxysilane is used instead of multi-nano titanium dioxide dendritic compounds.

[0079] Refer to GB / T1040.2-2006 to test tensile properties;

[0080] Refer to GB / T9341-2008 to test the bending performance;

[0081] Test the impact performance according to GB / T104.1-2008.

[0082] Table 1: Mechanical properties test results of various embodiments and comparative examples

[0083]

[0084] It can be seen from the table that the composite plastic prepared by the present invention has excellent toughness and pressure resistance.

[0085] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A high-toughness pressure-resistant composite plastic, characterized in that: The following raw materials are included in parts by weight: 100 parts of polypropylene, 1-5 parts of multi-nano titanium dioxide dendritic compound; Wherein, the high-toughness pressure-resistant composite plastic is prepared by the following process: Add polypropylene and multi-nano titanium dioxide dendritic compound into a high-speed mixer and mix them evenly, melt and extrude them from a twin-screw extruder, cut them into pellets, dry them, and inject them into an injection molding machine to obtain a high-toughness and pressure-resistant composite plastic; The preparation process of the multi-nano titanium dioxide dendritic compound is as follows: (1) Preparation process of tetraallylamine Under a nitrogen atmosphere, diallylamine is added to an N,N-dimethylformamide solvent, stirred and dispersed, and then a N,N-dimethylformamide solution of pyromellitic anhydride is added thereto, and the reaction is carried out at room temperature for 2-5 hours. After the reaction is completed, toluene precipitation is performed, washed, filtered, and dried to obtain pyromellitic anhydride tetraallylamine; (2) Preparation process of mercaptopropyltriethoxysilane modified nano-titanium dioxide Add nano silicon dioxide to a 90% by mass ethanol aqueous solution, stir and disperse, adjust the pH to 3-4 with glacial acetic acid, and ultrasonically disperse in a 100W ultrasonic cleaner for 1-3 hours. After the dispersion, add mercaptopropyl triethoxysilane at 75-85°C, stir and react for 5-8 hours, and after the dispersion, filter, wash, dry, extract with tetrahydrofuran, and dry to obtain mercaptopropyl triethoxysilane-modified nano titanium dioxide; (3) Preparation process of multi-nano titanium dioxide dendrimer compounds Add mercaptopropyl triethoxysilane modified nano titanium dioxide into N,N-dimethylformamide solvent, ultrasonically disperse in a 100W ultrasonic cleaner for 1-2 hours, then add tetraallylamine and initiator, stir and mix evenly, initiate reaction under ultraviolet light for 20-50 minutes, filter, wash, dry, extract with tetrahydrofuran, and dry to obtain multi-nanometer titanium dioxide dendritic compound.

2. The high-toughness pressure-resistant composite plastic according to claim 1, characterized in that: The temperatures of the three zones of the extruder are 180°C, 185°C, and 185°C, and the head temperature is 215°C.

3. The high-toughness pressure-resistant composite plastic according to claim 1, characterized in that: The injection molding temperature is three stages of 190° C., 180° C., and 160° C., and the injection pressure is 7 MPa.

4. The high-toughness pressure-resistant composite plastic according to claim 1, characterized in that: In the above (1), the usage ratio of diallylamine and pyromellitic anhydride is (1.8-2.5) g:1 g.

5. The high-toughness pressure-resistant composite plastic according to claim 1, characterized in that: In the above (2), the usage ratio of nano-silicon dioxide and mercaptopropyltriethoxysilane is 1g:(0.1-0.4)g.

6. The high-toughness pressure-resistant composite plastic according to claim 1, characterized in that: In the above (3), the usage ratio of mercaptopropyl triethoxysilane modified nano titanium dioxide, pyromellitic acid tetraallylamine, and initiator is 1g:(0.05-0.2)g:(0.004-0.01)g.

7. The high-toughness pressure-resistant composite plastic according to claim 1, characterized in that: In the above (3), the initiator is one of photoinitiator 907 and 2-methoxy-2-phenylacetophenone.

Images