CN106519123A - High-impact polypropylene grafted polymer and preparation method thereof - Google Patents

Abstract

A high-impact polypropylene graft polymer and a preparation method thereof belong to the technical field of polymer materials. It is characterized in that the high-impact polypropylene graft polymer contains a cross-linked "rubber phase" structure, and the polypropylene graft polymer of this structure has high impact strength and can maintain the tensile strength of raw materials. The polymer is prepared by an aqueous phase suspension grafting process. In the grafting reaction, the cross-linking monomer and the grafting monomer undergo a cross-linking copolymerization reaction on the polypropylene matrix, and the formed cross-linked copolymer is dispersed as a "rubber phase" In a polypropylene matrix. When the grafted polymer is subjected to external force, the cross-linked copolymer absorbs energy, and the impact resistance of the polypropylene grafted polymer is improved. The method is simple to operate, has low reaction temperature, is not easy to degrade, and does not use organic solvents (no volatile organic compound pollution). The impact resistance of the polypropylene graft polymer prepared by this process is significantly improved, while its tensile strength remains unchanged or decreases to a small extent.

Description

A kind of high-impact polypropylene graft polymer and preparation method thereof

technical field

The invention belongs to the technical field of polymer materials, in particular to a high-impact polypropylene graft polymer and a preparation method thereof.

Background technique

Polypropylene is a semi-crystalline thermoplastic made from the polymerization of propylene. It is widely used in the fields of automobiles, fibers, packaging and consumer goods due to its good mechanical properties, thermal stability, chemical stability and electrical insulation. However, polypropylene has poor compatibility with polar substances, poor adhesion, and low-temperature brittleness, which limits its application fields. Therefore, people often use various physical and chemical methods to modify polypropylene to meet different applications. Among them, copolymerization modification is to use high-efficiency catalysts to carry out random copolymerization or block copolymerization on the main chain of polypropylene during the propylene polymerization stage, which can modify polypropylene to a certain extent and improve the impact strength and toughness of polypropylene. Patent CN104558339A discloses a production method of impact-resistant polypropylene. The homopolymerization of propylene or the copolymerization of ethylene and propylene is carried out under the action of a catalyst. Through the synergy with the catalyst, the range of polymerization temperature is expanded, and the catalyst can maintain a relatively high High activity. Blending modification is to mix polymer materials (rubber, thermoplastic elastomer, etc.) Low-temperature brittleness, transparency, antistatic and coloring properties of polypropylene. Patent CN105566770A discloses an impact-resistant high-transparency polypropylene composition and its preparation method, using a high-speed mixer to mix polypropylene, polyolefin elastomer, metallocene linear low-density polyethylene, etc., and then granulate through twin-screw extrusion , to obtain impact-resistant and highly transparent polypropylene compositions, but this method is difficult to disperse the elastomer in the polypropylene matrix on a micron scale, and rubber-toughened polypropylene usually leads to a decrease in the tensile strength of the modified polypropylene.

Graft modification is a commonly used method for polypropylene modification, including solution method, melting method, solid phase method and suspension method. The solution grafting reaction has few by-products, a relatively high grafting rate, and a low degree of polypropylene degradation, but it requires the use of a large amount of organic solvents, which is easy to cause environmental pollution and high production costs, and is rarely used in industry. Melt grafting reaction is easy to operate, has no solvent recovery, low production cost, and can realize industrial continuous production, but the reaction temperature is high, the degradation degree of polypropylene is large, the reaction process is difficult to control, the grafting rate is low, and the residual unreacted monomer is difficult to remove . Solid-phase grafting reaction conditions are mild, post-treatment is simple, polypropylene degradation is low, and less solvent is used as an interface agent, but it is an intermittent reaction with low efficiency, long reaction time, and uneven grafting. Suspension grafting reaction is simple to operate, and the reaction temperature is low, the grafting rate is high, the degradation degree of polypropylene is low, the reaction is easy to control, the product is easy to separate, and there is no organic solvent recovery. It is a graft modification method with great development potential.

Suspension grafting, as a simple and mild grafting method, has been paid more and more attention by people. Patent CN1884326A discloses a porous polypropylene suspension grafting modification method, using saline solution as the suspension medium, which can increase the grafting rate , to reduce polymer degradation, and the grafted product can be used as a compatibilizer for blending polypropylene with other polymers, improving the compatibility of the two phases and improving the mechanical properties of composite materials, but salt water is corrosive to metal equipment. Patent CN101492517A discloses a preparation method of polypropylene grafted polymer. During the implementation process, no solvent, interface agent or suspension medium is used, and the conversion rate of grafted monomers can reach 95%, and at least 55% of the monomers are grafted to On polypropylene, the grafted product can improve the dispersion and compatibility of polyolefins and inorganic fillers. Li Zhuo et al studied the grafting of polypropylene with butyl acrylate in "A facile method to preparepolypropylene/poly(butyl acrylate)alloy via water–solid phase suspensiongrafting polymerization" (Chin.Chem.Lett, 2015, 26, 1351-1354.) In the polymerization reaction of ester, triethylene glycol diacrylate was selected as the crosslinking agent, which can significantly increase the grafting rate of butyl acrylate, but it is not stated whether the toughness of polypropylene can be improved.

The polypropylene used in the present invention is reactor particle technology polypropylene, which is proposed by Basell Corporation, and obtains spherical, porous polymer particles by controlling the polymerization growth of olefin monomers on a porous spherical catalyst carrier. The spherical polypropylene particles with a porous structure can be used as a microreactor for the copolymerization of monomers.

The polypropylene graft polymer obtained by the graft modification method is basically used as a compatibilizer for composite materials such as polypropylene and polar polymers and inorganic fillers. However, the present invention adopts a water-phase suspension grafting modification method, and grafts a cross-linked copolymer on the surface of porous polypropylene and inside micropores as a "rubber phase" to improve the toughness of polypropylene.

Contents of the invention

The invention provides a high-impact polypropylene graft polymer and a preparation method thereof. The polypropylene graft polymer contains a cross-linked "rubber phase" structure and has high impact strength. Another advantage of the present invention is that the grafting reaction is carried out in the confined space between the primary particles of polypropylene, and the grafted product is mixed as a "rubber phase" after being mixed by a twin-screw extruder or a torque rheometer. The compound can be well dispersed in the polypropylene matrix with micron or submicron size (the mechanical blending of polypropylene and rubber is difficult to achieve the micron-scale rubber phase dispersion size), so as to achieve the purpose of toughening polypropylene.

The technical solution for realizing the present invention: a high-impact polypropylene graft polymer and a preparation method thereof, mainly comprising the following steps: in parts by weight, dissolving 0.05-0.3 parts of initiator in 5-30 parts of graft The branch monomer and 0.5-10 parts of cross-linking monomer are configured into a mixed solution. Add 100 parts of porous polypropylene raw materials, shake well, and let stand for a period of time to ensure that the mixed solution of monomer and initiator is infiltrated into polypropylene. Add deionized water as a suspension to the reaction vessel and fill with inert gas. First raise the temperature to 60-70°C for 2-4 hours to make the grafted monomer fully swell the polypropylene, then continue to raise the temperature to 80-95°C for 2-8 hours. After the reaction is completed, the grafted product is suction-filtered with ethanol to remove unreacted monomers to obtain a polypropylene grafted polymer. Add antioxidant to polypropylene graft polymer, mix through twin-screw extruder or torque rheometer, so that the cross-linked copolymer grafted on the polypropylene matrix is uniformly dispersed, so as to obtain high toughness polypropylene graft polymer.

Further, the polypropylene is reactor particle technology polypropylene, which is directly grown into spherical and porous polypropylene particles in the reactor, which can provide a place for grafting reaction, and its weight part is 100 parts.

The graft monomer (monofunctional monomer) is methyl methacrylate, glycidyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, butyl methacrylate, hydroxypropyl methacrylate One or more of them, the parts by weight are 5-30 parts; the cross-linking monomer (multifunctionality monomer) is acrylated castor oil, diethylene glycol diacrylate, polypropylene glycol dimethacrylic acid Esters, one or more of diallyl maleate and trimethylolpropane triacrylate, the parts by weight are 0.5-10 parts.

The initiator is one or more of benzoyl peroxide, lauryl peroxide, tert-butyl peroxybenzoate, and tert-butyl peroxy-tert-valerate, and the parts by weight are 0.05-0.3 parts . Among them, benzoyl peroxide is preferred, and the primary free radicals produced by the thermal decomposition of benzoyl peroxide preferentially capture the hydrogen atoms on the polypropylene macromolecular chain to generate macromolecular chain free radicals, which can improve the grafting efficiency.

The antioxidant is one or more of antioxidant 1010, antioxidant 1076, and antioxidant 168.

Before adding water as the suspending medium, let it stand for a period of time to ensure that the mixture of monomer and initiator infiltrates the polypropylene particles (adsorption of the reaction solution inside the polypropylene particles). During the reaction, first set the temperature at 60-70°C for 2-4 hours to control the rate of primary free radicals generated by the decomposition of the initiator, and then control the rate of grafting reaction of monomers on polypropylene to realize the grafting of monomers to polypropylene. Fully swell to increase the grafting rate; continue to heat up to 80-95°C for 2-8h. After the reaction is completed, the unreacted monomers are eluted with ethanol or acetone, filtered with suction, and the unreacted grafted monomers are removed to obtain a polypropylene grafted polymer. The polypropylene graft polymer obtained by the reaction is mixed in a twin-screw extruder or a torque rheometer, so that the cross-linked copolymer grafted on the polypropylene can be well dispersed in the polypropylene matrix.

The invention relates to the preparation mechanism of polypropylene grafts. The initiator decomposes into primary free radicals at a certain temperature, abstracts hydrogen from polypropylene macromolecular chains, and forms macromolecular free radicals, thereby initiating monofunctionality and multifunctionality. The graft polymerization reaction of the body forms a grafted chain on the main chain of polypropylene. Due to the addition of multifunctional monomers, the grafted chain is a cross-linked network structure, so a polypropylene graft polymer with a cross-linked structure is obtained. The graft modification uses porous polypropylene particles as the reaction site, and the grafting reaction is carried out in the confined space formed by the primary polypropylene particles. The phase size of the obtained copolymer is micron or submicron scale, so the dispersed phase (in the grafted polymer The size of the "rubber phase" is on the micron or submicron scale. The usual rubber-toughened polypropylene extrusion and blending process cannot achieve such a uniform dispersion. The present invention can control the progress of the reaction by adjusting the added amount of different monomers, the ratio of different monomers and the amount of different initiators, and obtain graft polymers with different crosslinking degrees.

The beneficial effect of the present invention is that the grafted cross-linked copolymer is grafted on the polypropylene by adopting the water-phase suspension grafting modification method, and moderate cross-linking can make the polypropylene grafted polymer form a spatial network structure. When the polypropylene grafted polymer is subjected to external force, the network structure is conducive to energy absorption, and the impact resistance is improved. Among them, the impact strength of the polypropylene raw material is 2-4kJ/m ² , the tensile strength is 37-44MPa, and the impact strength of the prepared polypropylene graft polymer is 4-10kJ/m ² , the tensile strength is 29- 41MPa. The tensile strength of the polypropylene graft polymer prepared by the method remains basically unchanged or decreases slightly, and the impact strength is significantly improved.

Description of drawings

Fig. 1 is the infrared spectrogram of polypropylene (PP) and polypropylene grafted butyl acrylate (BA)/acrylated castor oil (ACO) polymer. Comparing the infrared spectra of polypropylene and polypropylene grafted polymer, it can be seen that the grafted polymer has an obvious characteristic absorption peak of ester carbonyl at 1734cm-1, indicating that the monomer has been successfully grafted to polypropylene.

Where (a) GP=0% (pure PP); (b) GP=9.1%; (c) GP=13.9%; (d) GP=18.4%

Wherein: GP (grafting ratio)=(weight of grafted product after extraction-weight of pure polypropylene)/weight of pure polypropylene.

Figure 2 is the effect of different monomer additions on the tensile and impact strength of polypropylene grafted butyl acrylate/acrylated castor oil polymer. As the content of butyl acrylate and acrylated castor oil increases, the tensile strength of the grafted polymer decreases slightly and then tends to be stable, and the impact strength shows an upward trend, and the increase range is relatively large, which shows that the prepared polypropylene The toughness of the grafted polymer has been significantly improved while maintaining a certain strength.

detailed description

Example 1

Dissolve 0.2g of benzoyl peroxide in 16.0g of butyl acrylate and 4.0g of acrylated castor oil, add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene, add deionized Water is used as the suspending medium, filled with argon to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 70°C, and the reaction was performed for 2 hours, then the temperature was raised to 90°C, and the reaction was continued for 2 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 116.91 g of grafted products. Take 3.1222g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 3.0980g. After calculation, the grafting rate of the product is 16.0%, and the grafting efficiency is 94.6%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 3.24g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to make the grafted product mix evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 34.42 MPa, and the impact strength was 6.57 kJ/m ² .

Example 2

Dissolve 0.3g of benzoyl peroxide in 14.0g of butyl acrylate and 6.0g of acrylated castor oil, add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene, add deionized Water is used as the suspending medium, filled with argon to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial reaction temperature is 70°C, react for 2h, then raise the temperature to 90°C, and react for 6h. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 115.60 g of grafted products. Take 3.1276g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 3.1144g. After calculation, the grafting rate of the product is 15.1%, and the grafting efficiency is 96.9%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 1.83g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to make the grafted product mix evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 33.15 MPa, and the impact strength was 7.16 kJ/m ² .

Example 3

Dissolve 0.2g of benzoyl peroxide in 10.0g of butyl acrylate and 10.0g of acrylated castor oil, add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene, add deionized Water is used as the suspending medium, filled with argon to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial reaction temperature was 60°C, and the reaction was carried out for 4 hours, then the temperature was raised to 80°C, and the reaction was carried out for 8 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 110.62 g of grafted products. Take 3.1907g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 3.1701g. After calculation, the grafting rate of the product is 9.9%, and the grafting efficiency is 93.3%. Under the conditions of 230°C and 2.16kg, the melt index of the grafted product was measured to be 0.75g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to make the grafted product mix evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 31.87 MPa, and the impact strength was 8.33 kJ/m ² .

Example 4

Dissolve 0.3g of benzoyl peroxide in 30.0g of butyl acrylate and 3.0g of polypropylene glycol dimethacrylate, add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorbed on the polypropylene, add Deionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial reaction temperature was 60°C, and the reaction was carried out for 4 hours, then the temperature was raised to 80°C, and the reaction was carried out for 8 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 128.99 g of grafted products. Take 4.0866g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.0619g. After calculation, the grafting rate of the product is 28.2%, and the grafting efficiency is 97.3%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 1.95g/10min. Take 100 g of the grafted product, add 0.3 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to mix the grafted product evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 32.51 MPa, and the impact strength was 4.33 kJ/m ² .

Example 5

Dissolve 0.2g of benzoyl peroxide in 16.0g of butyl acrylate and 4.0g of polypropylene glycol dimethacrylate, add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene, add Deionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial reaction temperature is 65°C, react for 2 hours, then raise the temperature to 95°C, and react for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 118.81 g of grafted products. Take 4.0632g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.0361g. After calculation, the grafting rate of the product is 18.0%, and the grafting efficiency is 95.8%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 1.83g/10min. Take 100 g of the grafted product, add 0.3 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to mix the grafted product evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 33.58 MPa, and the impact strength was 5.04 kJ/m ² .

Example 6

Dissolve 0.3g of benzoyl peroxide in 20.0g of butyl acrylate, add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorbed on the polypropylene, add deionized water as the suspension medium, and fill with argon Remove the air in the reaction vessel, and place the sealed reaction vessel in an oil bath for heating and stirring. The reaction temperature was set at 95° C., and the reaction time was 6 hours. The reaction product was filtered with ethanol to wash away unreacted monomers to obtain 118.78 g of grafted products. Take 4.0894g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.0588g. After calculation, the grafting rate of the product is 17.9%, and the grafting efficiency is 95.3%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 2.47g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.2 g of antioxidant 168, and knead for 20 minutes in a torque rheometer, so that the grafted product is mixed evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 30.85 MPa, and the impact strength was 4.76 kJ/m ² .

Example 7

Dissolve 0.3g of benzoyl peroxide in 20.0g of butyl acrylate, add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorbed on the polypropylene, add deionized water as the suspension medium, and fill with argon Remove the air in the reaction vessel, and place the sealed reaction vessel in an oil bath for heating and stirring. The initial temperature of the reaction was set at 65°C for 2 hours of reaction, then raised to 95°C for 6 hours of reaction. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 119.42 g of grafted products. Take 4.1160g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.1031g. After calculation, the grafting rate of the product is 19.0%, and the grafting efficiency is 98.1%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 2.29g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.2 g of antioxidant 168, and knead for 20 minutes in a torque rheometer, so that the grafted product is mixed evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 30.12 MPa, and the impact strength was 4.98 kJ/m ² .

Example 8

Dissolve 0.05g of benzoyl peroxide in 4.50g of butyl acrylate and 0.50g of acrylated castor oil, then add 100g of polypropylene, shake well, and let stand for 10 hours to make the monomer fully adsorbed on the polypropylene matrix, add Deionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 104.24 g of grafted products. 4.4271g of the grafted product was extracted with acetone for 24 hours in a Soxhlet extractor, and then dried. The remaining weight of the product was 4.4215g. After calculation, the grafting rate of the reaction is 4.1%, and the grafting efficiency is 96.9%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 7.86g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to make the grafted product mix evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 35.00 MPa, and the impact strength was 3.81 kJ/m ² .

Example 9

Dissolve 0.10g of benzoyl peroxide in 9.00g of butyl acrylate and 1.00g of acrylated castor oil, then add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene, then add Ionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 109.38 g of grafted products. Take 4.6968g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.6868g. After calculation, the grafting rate of the reaction is 9.1%, and the grafting efficiency is 97.5%. Under the conditions of 230°C and 2.16kg, the melt index of the grafted product was measured to be 5.92g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to make the grafted product mix evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 31.86 MPa, and the impact strength was 4.03 kJ/m ² .

Example 10

Dissolve 0.15g of benzoyl peroxide in 13.50g of butyl acrylate and 1.50g of acrylated castor oil, then add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene. Ionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 114.26 g of grafted products. 4.4271g of the grafted product was extracted with acetone for 24 hours in a Soxhlet extractor, and then dried. The remaining weight of the product was 4.4215g. After calculation, the grafting rate of the reaction is 13.9%, and the grafting efficiency is 97.6%. Under the conditions of 230°C and 2.16kg, the melt index of the grafted product was measured to be 4.69g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to make the grafted product mix evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 30.08 MPa, and the impact strength was 6.41 kJ/m ² .

Example 11

Dissolve 0.20g of benzoyl peroxide in 18.00g of butyl acrylate and 2.00g of acrylated castor oil, then add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene. Ionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 118.83 g of grafted products. Take 4.5252g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.5100g. After calculation, the grafting rate of the reaction is 18.4%, and the grafting efficiency is 97.9%. Under the conditions of 230°C and 2.16kg, the melt index of the grafted product was measured to be 2.82g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to make the grafted product mix evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 29.54 MPa, and the impact strength was 8.98 kJ/m ² .

Example 12

Dissolve 0.25g of benzoyl peroxide in 22.50g of butyl acrylate and 2.50g of acrylated castor oil, then add 100g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene. Ionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 118.59 g of grafted products. 4.5672g of the grafted product was extracted with acetone for 24 hours in a Soxhlet extractor, and then dried. The remaining weight of the product was 4.5481g. After calculation, the grafting rate of the reaction is 18.2%, and the grafting efficiency is 98.0%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 1.75g/10min. Take 100 g of the grafted product, add 0.2 g of antioxidant 1010 and 0.1 g of antioxidant 168, and knead in a torque rheometer for 20 minutes to make the grafted product mix evenly. The grafted product after kneading was injection-molded into tensile and impact samples, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 29.37 MPa, and the impact strength was 8.27 kJ/m ² .

Example 13

Dissolve 0.10g of benzoyl peroxide in 8.75g of butyl acrylate and 1.25g of polypropylene glycol dimethacrylate, add 200g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene, add Deionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 207.67 g of grafted products. 4.0649g of the grafted product was extracted with acetone in a Soxhlet extractor for 24 hours, and then dried, the remaining weight of the product was 4.0546g. After calculation, the grafting rate of the reaction is 3.6%, and the grafting efficiency is 93.1%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 2.52g/10min. Take 200g of the grafted product, add 0.3g of antioxidant 1010 and 0.2g of antioxidant 168, and extrude and mix through a twin-screw extruder. The extruded grafted product was injection molded into tensile and impact strips, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 40.37 MPa, and the impact strength was 4.21 kJ/m ² .

Example 14

Dissolve 0.20g of benzoyl peroxide in 17.50g of butyl acrylate and 2.50g of polypropylene glycol dimethacrylate, add 200g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene, add Deionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 218.99 g of grafted products. Take 4.0759g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.0612g. After calculation, the grafting rate of the reaction is 9.1%, and the grafting efficiency is 95.8%. Under the conditions of 230°C and 2.16kg, the melt index of the grafted product was measured to be 2.12g/10min. Take 200g of the grafted product, add 0.3g of antioxidant 1010 and 0.2g of antioxidant 168, and extrude and mix through a twin-screw extruder. The extruded grafted product was injection molded into tensile and impact strips, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 39.23 MPa, and the impact strength was 6.73 kJ/m ² .

Example 15

Dissolve 0.30g of benzoyl peroxide in 26.25g of butyl acrylate and 3.75g of polypropylene glycol dimethacrylate, add 200g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene, add Deionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 229.16 g of grafted products. Take 4.1391g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.1198g. After calculation, the grafting rate of the reaction is 14.1%, and the grafting efficiency is 96.3%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 2.00g/10min. Take 200g of the grafted product, add 0.3g of antioxidant 1010 and 0.2g of antioxidant 168, and extrude and mix through a twin-screw extruder. The extruded grafted product was injection molded into tensile and impact strips, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 33.23 MPa, and the impact strength was 6.22 kJ/m ² .

Example 16

Dissolve 0.40g of benzoyl peroxide in 35.00g of butyl acrylate and 5.00g of polypropylene glycol dimethacrylate, add 200g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorb on the polypropylene, add Deionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 238.40 g of grafted products. Take 4.1037g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.0808g. After calculation, the grafting rate of the reaction is 18.5%, and the grafting efficiency is 96.5%. At 230°C and 2.16kg, the melt index of the grafted product was measured to be 1.97g/10min. Take 200g of the grafted product, add 0.3g of antioxidant 1010 and 0.2g of antioxidant 168, and extrude and mix through a twin-screw extruder. The extruded grafted product was injection molded into tensile and impact strips, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 29.05 MPa, and the impact strength was 4.84 kJ/m ² .

Example 17

Dissolve 0.50g of benzoyl peroxide in 43.75g of butyl acrylate and 6.25g of polypropylene glycol dimethacrylate, add 200g of polypropylene, shake well, and let it stand for 10 hours to make the monomer fully adsorbed on the polypropylene, add Deionized water is used as the suspension medium, filled with argon gas to remove the air in the reaction vessel, and the airtight reaction vessel is placed in an oil bath for heating and stirring. The initial temperature of the reaction was 65°C, and reacted for 4 hours, then raised the temperature to 90°C, and reacted for 4 hours. The reaction product was suction-filtered with ethanol to wash away unreacted monomers to obtain 246.95 g of grafted products. Take 4.0920g of the grafted product and extract it with acetone for 24 hours in a Soxhlet extractor, and then dry it. The remaining weight of the product is 4.0615g. After calculation, the grafting rate of the reaction is 22.6%, and the grafting efficiency is 96.1%. Under the conditions of 230°C and 2.16kg, the melt index of the grafted product was measured to be 1.91g/10min. Take 200g of the grafted product, add 0.3g of antioxidant 1010 and 0.2g of antioxidant 168, and extrude and mix through a twin-screw extruder. The extruded grafted product was injection molded into tensile and impact strips, and the tensile and impact strengths were tested respectively according to the standards of ISO527 and ISO178. The measured tensile strength was 32.40 MPa, and the impact strength was 4.27 kJ/m ² .

Claims (5)

1. a preparation method of high-impact polypropylene graft polymer, is characterized in that: this polymer is made by aqueous phase suspension grafting modification method, and in grafting reaction, polypropylene, initiator, graft The graft monomer and cross-linking monomer are added to the reaction vessel; under heating conditions, the graft monomer and the cross-linking monomer undergo cross-linking copolymerization reaction on the polypropylene matrix, and the formed cross-linked copolymer acts as a "rubber phase". "Dispersed in the polypropylene matrix; in the grafting reaction, the initial reaction temperature is maintained at 60-70°C for 2-4h, and the temperature continues to rise, the reaction temperature is 80-95°C, and the reaction time is 2-8h. 2. preparation method according to claim 1, is characterized in that: described grafting monomer is monofunctionality monomer, and its parts by weight are counted as 5-30 parts with 100 parts of polypropylenes; Cross-linking monomer is The weight part of the multifunctional monomer is 0.5-10 parts based on 100 parts of polypropylene. 3. The preparation method according to claim 2, characterized in that: the monofunctional monomer is methyl methacrylate, glycidyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, methyl One or more of butyl acrylate and hydroxypropyl methacrylate. 4. preparation method according to claim 2, is characterized in that: described polyfunctionality monomer is acrylated castor oil, diethylene glycol diacrylate, polypropylene glycol dimethacrylate, maleic acid dimethacrylate Allyl ester, one or more of trimethylolpropane triacrylate. 5. preparation method according to claim 1 is characterized in that: described grafting reaction, the initiator that adds is benzoyl peroxide, lauryl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxide One or several types of tert-butyl valerate, the parts by weight are 0.05-0.3 parts based on 100 parts of polypropylene.