A kind of anti-aging PP plastic and preparation method thereof
By adding a modified composite algae extract to polypropylene plastics, the issues of molecular chain degradation are addressed, enhancing anti-aging and mechanical properties while maintaining environmental sustainability.
Patent Information
- Application Number
- CN202210755850.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-06-29
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2042-06-29
AI Technical Summary
Existing polypropylene plastics suffer from molecular chain degradation due to light, heat, and oxygen, leading to yellowing, stickiness, decreased mechanical properties, and limited weather and wear resistance, which restricts their application scope and development.
Incorporating a composite algae extract, modified with carboxyl and ester carbonyl groups, into polypropylene plastics to enhance antioxidant properties, improve compatibility, and introduce antibacterial effects, while using plant fibers and other additives to create an environmentally friendly anti-aging material.
The composite algae extract effectively delays oxidative degradation, enhances toughness and antibacterial properties, and improves adhesion with the polypropylene matrix, resulting in improved anti-aging and mechanical performance without environmental harm.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of plastic preparation, and in particular to an anti-aging PP plastic and a preparation method thereof. Background Art
[0002] Polypropylene (PP) is one of the fastest growing types of general-purpose thermoplastics. Compared with other general-purpose plastics, PP has good general properties such as a wide source of raw materials, very low cost, simple molding and processing, and very low density. It is non-toxic, has excellent processing performance, good heat resistance, and can be used for a long time at a temperature of 110-120°C. It has high yield and tensile strength, elastic modulus, and good electrical insulation properties, excellent stress crack resistance and chemical resistance. It has been widely used in the fields of chemical industry, food, packaging, building materials, medicine, automobiles, etc., and is spread throughout all aspects of our daily life.
[0003] Although polypropylene has been widely developed and applied in many fields, its molecular chain structure is prone to yellowing, stickiness, and decreased mechanical properties under the influence of light (ultraviolet rays), heat, and oxygen. In addition, polypropylene has poor weather resistance and wear resistance under low temperature conditions, which limits the application scope and development prospects of polypropylene. Therefore, modification and anti-aging research on polypropylene is essential to expand the application scope of polypropylene.
[0004] Polypropylene aging is a phenomenon in which the chemical components and physical structure of polypropylene undergo significant changes and the performance is weakened due to the combined effects of light, heat and chemical catalysis during the manufacturing, storage, transportation and utilization processes. Among them, light and heat are the two factors that play a leading role in polypropylene aging, which are called photo-oxidation aging and thermal-oxidation aging, respectively. They can cause polypropylene to automatically undergo catalytic oxidation reactions. There are four main changes in polypropylene aging, namely changes in appearance, physical properties, mechanical properties and electrical properties, which greatly limits its outdoor use.
[0005] Antioxidants are substances that can reduce the side effects of oxygen, capture and neutralize free radicals, reduce their subsequent damage, and increase service life. The main mechanism of action is that antioxidants reduce the oxygen content through reduction reactions, combine with peroxides produced by previous oxidation reactions of polymers, and interrupt chain reactions. Adding antioxidants to improve the anti-aging ability of PP is currently the most common method. In recent years, people have conducted extensive research on this, mainly divided into synthetic antioxidants and natural antioxidants. Studies have found that the addition of hydroxytyrosol to PP increases the oxidation induction time and oxidation induction temperature, showing good antioxidant properties. However, chemically synthesized antioxidants have a high preparation cost, and the organic substances involved in the experimental process can also cause harm and pollution to the human body and the environment.
[0006] Chinese patent CN 103881237 A discloses an anti-aging polypropylene plastic, which is composed of the following raw material components by weight: 100 parts of polypropylene, 0.4-0.6 parts of antioxidant 1010, 0.1-0.3 parts of light stabilizer, 0.2-0.3 parts of ultraviolet absorber, 36-40 parts of carbon black, 2-4 parts of nano titanium dioxide, 12-16 parts of epoxy resin, 15-20 parts of melamine, 0.2-0.6 parts of dispersant, and 0.5-0.8 parts of coupling agent. The anti-aging polypropylene plastic of the invention is added with nano titanium dioxide, and the nano titanium dioxide has good dispersibility in the polypropylene plastic; the anti-aging polypropylene plastic of the invention is added with melamine, so that the polypropylene plastic prepared by the invention has flame retardant properties and meets the requirements for outdoor use; the polypropylene plastic prepared by the invention has good impact resistance, anti-aging performance, and toughness enhancement is also improved.
[0007] Chinese patent CN 104327381 A discloses a new type of durable anti-aging polypropylene plastic, which is prepared from 60-120 parts of copolymerized polypropylene, 0.3-0.5 parts of antioxidant, 10-15 parts of epoxy resin, 6-9 parts of compatibilizer, 0.15-0.35 parts of ultraviolet absorber, 0.3-0.5 parts of dispersant, 1.5-2.5 parts of auxiliary agent, 16-20 parts of melamine and 0.15-0.25 parts of light stabilizer. The new type of durable anti-aging polypropylene plastic of the invention is added with melamine, so that the polypropylene plastic prepared by the invention has good anti-aging and flame retardant properties, and also has good wear resistance, heat resistance, chemical resistance and environmental protection; the production process is simple, the processing and molding are convenient, the materials are easy to obtain, and the cost is low. However, most of the antioxidants in the existing technology cause serious environmental pollution, and some natural antioxidants are not compatible with the polypropylene matrix. Therefore, it is particularly important to develop a PP plastic that has good anti-aging properties and is green and environmentally friendly. Summary of the invention
[0008] In view of the above-mentioned deficiencies in the prior art, the present invention provides an anti-aging PP plastic and a preparation method thereof. The specific technical scheme is as follows:
[0009] An anti-aging PP plastic comprises the following raw materials in parts by weight:
[0010] 80-100 parts of polypropylene, 9-13 parts of plant fiber, 4-8 parts of antibacterial agent, 1-4 parts of heat stabilizer, 1-5 parts of dispersant, and 5-7 parts of cross-linking agent.
[0011] Plant fibers generally include woody fibers, herbaceous fibers and rattan fibers. The recycling rate of plant fibers is low, and many of them will be incinerated, which not only pollutes the ecological environment but also wastes resources. On the other hand, modern society has put forward higher requirements for plastic materials, such as reducing costs and improving their own insufficient performance. Therefore, people began to compound a limited number of single plastics into various new composite materials to meet various requirements.
[0012] The plant fiber is one of jute fiber and corn straw fiber.
[0013] The antibacterial agent is one of N-(trichloromethylthio)phthalimide, ascorbyl stearate and butylated hydroxyanisole.
[0014] The heat stabilizer is one of propylene oxide and calcium isooctanoate.
[0015] The dispersant is one or more of stearic acid, polyethylene wax, liquid paraffin and polyethylene glycol.
[0016] The cross-linking agent is diethylaminopropylamine.
[0017] Furthermore, the anti-aging PP plastic comprises the following raw materials in parts by weight:
[0018] 80-100 parts of polypropylene, 9-13 parts of plant fiber, 4-8 parts of antibacterial agent, 1-4 parts of heat stabilizer, 1-5 parts of dispersant, 5-7 parts of cross-linking agent and 2-6 parts of compound algae extract.
[0019] The service life of polypropylene plastics essentially depends on their antioxidant capacity. Therefore, it is often necessary to add oxidative protective agents when preparing polypropylene plastics. However, for environmental protection and low pollution, many natural oxidative protective agents have become the focus of research. Algae is an important source of natural active ingredients. Scientists have long studied the biological activity of natural compounds in algae. The active ingredients of algae can be roughly divided into two categories: one is mainly viscous polysaccharides; the other is smaller in molecular weight, mainly including lipids, phenols, terpenes, alkaloids and carotenoids. Almost all plants, including seaweed, are exposed to an environment of high light intensity and high oxygen concentration for photosynthesis, and are inevitably subject to strong oxidative stress, leading to the formation of free radicals, but they rarely suffer serious oxidative damage in metabolism. This fact shows that there must be some protective antioxidant mechanisms and natural antioxidant active ingredients in their cells.
[0020] Furthermore, the composite algae extract is prepared by mixing the Sargassum henselae extract and the Spirulina salina powder.
[0021] Preferably, the composite algae extract is prepared by mixing the Sargassum henselae extract and the Spirulina saliza powder in a mass ratio of 1:3 to 6.
[0022] The Henkelp extract is prepared by the following method: weighing 80 to 100 g of Henkelp dry powder, adding methanol-chloroform organic phase solution at a solid-liquid ratio of 1:5 to 8 g / mL, with a volume ratio of methanol to chloroform of 3:1, refluxing at a constant temperature of 100°C hot water for 2 to 3 times, each time for 50 to 60 minutes, vacuum filtering to obtain a filtrate, concentrating the filtrate by rotary evaporation so that the volume of the concentrate is 1 / 8 to 1 / 5 of the volume of the filtrate, and then freeze-drying at -40 to -30°C for 8 to 10 hours to obtain the Henkelp extract.
[0023] The inventors have found that adding the composite algae extract to polypropylene plastic can play an effective anti-aging role, and the efficiency of its protection of plastic is largely determined by the polyphenols in the composite algae extract. The activity of the composite algae extract hinders the decay of free radicals involved in oxidation in the plastic. Especially when the plastic is affected by light aging, light can promote the conversion of the composite algae extract from the initial structure to a substructure with shielding and protection functions. At the same time, the thermal stability of the composite algae extract is better than that of other natural oxidants and is not easy to degrade. However, the inventors found in the experiment that the biocompatibility of the composite algae extract and the polypropylene plastic matrix is insufficient, so the composite algae extract needs to be further processed.
[0024] More preferably, the composite algae extract is prepared by mixing modified Sargassum henselae extract and Spirulina salizawa powder in a mass ratio of 1:3 to 6.
[0025] Most preferably, the composite algae extract is prepared by mixing modified Sargassum henselae extract and Spirulina salizae powder in a mass ratio of 1:4.
[0026] Furthermore, the modified Henkel Algae extract is prepared by the following method: weighing 80-100 g of Henkel Algae dry powder, adding methanol-chloroform organic phase solution at a solid-liquid ratio of 1:5-8 g / mL, the volume ratio of methanol to chloroform is 3:1, 100°C hot water is refluxed at a constant temperature for 2-3 times, each time for 50-60 min, vacuum filtration to obtain a filtrate, the filtrate is concentrated by rotary evaporation so that the volume of the concentrate is 1 / 8-1 / 5 of the volume of the filtrate, and then freeze-dried at -40--30°C for 8-10 h to obtain the Henkel Algae extract, and then taking 20-40 g of the Henkel Algae extract and adding 80-100 mL of water to mix, and then adjusting the pH value of the system to 7.5-8.5 with 0.1-0.3 mol / L sodium hydroxide aqueous solution, and then heating to 40-50°C, and then measuring 10-30 mL A 15-20 wt% sodium hypochlorite aqueous solution is added dropwise within 20-30 minutes, and 3-5 g of sodium bisulfite is added after the reaction is completed; then a 52-68 wt% bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride ethanol solution is added dropwise, and after reacting for 2-4 hours, 0.1-0.2 mol / L hydrochloric acid is added to adjust the pH to 5.5-6.5, and then the modified Sargassum henselae extract is obtained through water washing, suction filtration and drying.
[0027] The Hensonian Sargassum extract has been modified to introduce carboxyl groups and successfully esterified to introduce ester carbonyl groups, which changes the steric hindrance inside the Hensonian Sargassum extract, making the surface of the Hensonian Sargassum extract rough and significantly increasing the number of holes. Therefore, it is more conducive to the compatibility of the Hensonian Sargassum extract with the polypropylene matrix, enhancing the adhesion between the two, and enhancing the protection of the composite algae extract for polypropylene plastics, making PP plastics have stronger anti-aging properties. At the same time, it can also enhance the toughness of PP plastics. In addition, the composite algae extract also contains antibacterial active substances, which can enhance the antibacterial properties of polypropylene plastics.
[0028] The present invention also provides a method for preparing the above-mentioned anti-aging PP plastic, comprising the following steps:
[0029] S1 weighs polypropylene, plant fiber, antibacterial agent, heat stabilizer, dispersant, and crosslinking agent according to the formula, adds them into a mixer, mixes and stirs evenly, the stirring speed is 400-600r / min, the mixing temperature is 120-150°C, the mixing time is 20-30min, and after mixing evenly, a mixed material is obtained;
[0030] S2: the mixed material is mixed with the composite algae extract and then added into a twin-screw extruder granulator, and plasticized and pelletized at 150-160° C. to obtain the anti-aging PP plastic.
[0031] The present invention adds a composite algae extract during the preparation of polypropylene plastic, thereby improving the heat resistance and radiation resistance of the plastic. The cracking process of polypropylene under light and heat produces a high concentration of oxidative initiators, and the composite algae extract can effectively delay and slow down degradation. The Henkel sargassum extract and the salt spirulina powder in the present invention can block the reaction of free radicals converting into peroxy structures. The Henkel sargassum extract is modified to introduce carboxyl groups and successfully esterified to introduce ester carbonyl groups, so that the steric hindrance inside the Henkel sargassum extract changes, so that the surface of the Henkel sargassum extract becomes rough and the number of holes increases significantly, which is more conducive to the compatibility of the Henkel sargassum extract with the polypropylene matrix and enhances the adhesive effect of the two. Compared with the prior art, the composite algae extract added in the present invention can give polypropylene plastics anti-aging, antibacterial and toughness enhancement properties, while being environmentally friendly, further broadening the application of PP plastics. DETAILED DESCRIPTION
[0032] The raw materials in the examples are introduced as follows:
[0033] Polypropylene, PP RJ700, Dongguan Yingxiang Plastic Raw Materials Co., Ltd.;
[0034] Jute fiber, length 70 mm, Dongguan Shuncheng Textile Co., Ltd.;
[0035] Spirulina salt powder, 100 mesh, Shanghai Guangyu Biotechnology Co., Ltd.;
[0036] Sargassum henselae dry powder, 120-140 mesh, Jinan Texing Chemical Co., Ltd.;
[0037] Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, CAS: 1719-83-1, Shanghai Jizhi Biochemical Technology Co., Ltd.
[0038] Example 1
[0039] A preparation method of anti-aging PP plastic comprises the following steps:
[0040] S1 weighed 100 kg of polypropylene, 12 kg of jute fiber, 5 kg of L-ascorbyl stearate, 3 kg of calcium 2-ethylhexanoate, 4 kg of polyethylene glycol-1000, 6 kg of diethylaminopropylamine, and 4 kg of compound algae extract, and added them into a mixer and mixed and stirred evenly at a stirring speed of 500 r / min, a mixing temperature of 140° C., and a mixing time of 30 min. After mixing evenly, a mixed material was obtained;
[0041] S2: The mixed material is mixed with the composite algae extract and then added into a twin-screw extruder granulator, and plasticized and pelletized at 155° C. to obtain the anti-aging PP plastic.
[0042] The composite algae extract is prepared by mixing modified Sargassum henselae extract and Spirulina salizae powder in a mass ratio of 1:4.
[0043] The modified Henkel Algae extract is prepared by the following method: weighing 100 g of Henkel Algae dry powder, adding methanol-chloroform organic phase solution at a solid-liquid ratio of 1:8 g / mL, with a volume ratio of methanol to chloroform of 3:1, refluxing at a constant temperature of 100°C hot water for 3 times, each time for 60 minutes, vacuum filtering to obtain a filtrate, concentrating the filtrate by rotary evaporation so that the volume of the concentrate is 1 / 8 of the volume of the filtrate, and then freeze-drying at -40°C for 10 hours to obtain the Henkel Algae extract, then taking 30 g of the Henkel Algae extract, adding 90 mL of water and mixing, then adjusting the pH value of the system to 8.5 with a 0.2 mol / L sodium hydroxide aqueous solution, then heating to 50°C, and then measuring 20 mL A 15wt% aqueous sodium hypochlorite solution was added dropwise within 30 minutes, and 4g of sodium bisulfite was added after the reaction was completed; then a 61wt% bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride ethanol solution was added dropwise, and after reacting for 4 hours, 0.1mol / L hydrochloric acid was added to adjust the pH to 6.5, and then the modified Sargassum henselae extract was obtained through water washing, suction filtration and drying.
[0044] Example 2
[0045] A preparation method of anti-aging PP plastic comprises the following steps:
[0046] S1 weighed 100 kg of polypropylene, 12 kg of jute fiber, 5 kg of L-ascorbyl stearate, 3 kg of calcium 2-ethylhexanoate, 4 kg of polyethylene glycol-1000, 6 kg of diethylaminopropylamine, and 4 kg of compound algae extract, and added them into a mixer and mixed and stirred evenly at a stirring speed of 500 r / min, a mixing temperature of 140° C., and a mixing time of 30 min. After mixing evenly, a mixed material was obtained;
[0047] S2: The mixed material is mixed with the composite algae extract and then added into a twin-screw extruder granulator, and plasticized and pelletized at 155° C. to obtain the anti-aging PP plastic.
[0048] The composite algae extract is prepared by mixing the Sargassum henselae extract and the Spirulina salina powder in a mass ratio of 1:4.
[0049] The Henkel Algae extract is prepared by the following method: weighing 100 g of Henkel Algae dry powder, adding methanol-chloroform organic phase solution at a solid-liquid ratio of 1:8 g / mL, with a volume ratio of methanol to chloroform of 3:1, refluxing at a constant temperature of 100°C hot water for 3 times, each time for 60 minutes, vacuum filtering to obtain a filtrate, concentrating the filtrate by rotary evaporation so that the volume of the concentrate is 1 / 8 of the volume of the filtrate, and then freeze-drying at -40°C for 10 hours to obtain the Henkel Algae extract.
[0050] Example 3
[0051] A preparation method of anti-aging PP plastic comprises the following steps:
[0052] S1 weighed 100 kg of polypropylene, 12 kg of jute fiber, 5 kg of L-ascorbyl stearate, 3 kg of calcium 2-ethylhexanoate, 4 kg of polyethylene glycol-1000, 6 kg of diethylaminopropylamine, and 4 kg of Henkel kelp extract, and added them into a mixer and mixed and stirred evenly at a stirring speed of 500 r / min, a mixing temperature of 140° C., and a mixing time of 30 min. After mixing evenly, a mixed material was obtained;
[0053] S2: the mixed material is mixed with the Henkel kelp extract and then added into a twin-screw extruder granulator, and plasticized and pelletized at 155° C. to obtain the anti-aging PP plastic.
[0054] The Henkel Algae extract is prepared by the following method: weighing 100 g of Henkel Algae dry powder, adding methanol-chloroform organic phase solution at a solid-liquid ratio of 1:8 g / mL, with a volume ratio of methanol to chloroform of 3:1, refluxing at a constant temperature of 100°C hot water for 3 times, each time for 60 minutes, vacuum filtering to obtain a filtrate, concentrating the filtrate by rotary evaporation so that the volume of the concentrate is 1 / 8 of the volume of the filtrate, and then freeze-drying at -40°C for 10 hours to obtain the Henkel Algae extract.
[0055] Example 4
[0056] A preparation method of anti-aging PP plastic comprises the following steps:
[0057] S1 weighed 100 kg of polypropylene, 12 kg of jute fiber, 5 kg of L-ascorbyl stearate, 3 kg of calcium 2-ethylhexanoate, 4 kg of polyethylene glycol-1000, 6 kg of diethylaminopropylamine, and 4 kg of salt-salted spirulina powder, and added them into a mixer and mixed and stirred evenly at a stirring speed of 500 r / min, a mixing temperature of 140° C., and a mixing time of 30 min. After mixing evenly, a mixed material was obtained;
[0058] S2: the mixed material is mixed with the salt spirulina powder and then added into a twin-screw extruder granulator, and plasticized and pelletized at 155° C. to obtain the anti-aging PP plastic.
[0059] Example 5
[0060] A preparation method of anti-aging PP plastic comprises the following steps:
[0061] S1 weighed 100 kg of polypropylene, 12 kg of jute fiber, 5 kg of L-ascorbyl stearate, 3 kg of calcium 2-ethylhexanoate, 4 kg of polyethylene glycol-1000, 6 kg of diethylaminopropylamine, and 4 kg of modified Sargassum henselae extract, and added them into a mixer and mixed and stirred evenly at a stirring speed of 500 r / min, a mixing temperature of 140° C., and a mixing time of 30 min. After mixing evenly, a mixed material was obtained;
[0062] S2: the mixed material is mixed with the modified Sargassum henselae extract and then added into a twin-screw extruder granulator, and plasticized and pelletized at 155° C. to obtain the anti-aging PP plastic.
[0063] The modified Henkel Algae extract is prepared by the following method: weighing 100 g of Henkel Algae dry powder, adding methanol-chloroform organic phase solution at a solid-liquid ratio of 1:8 g / mL, with a volume ratio of methanol to chloroform of 3:1, refluxing at a constant temperature of 100°C hot water for 3 times, each time for 60 minutes, vacuum filtering to obtain a filtrate, concentrating the filtrate by rotary evaporation so that the volume of the concentrate is 1 / 8 of the volume of the filtrate, and then freeze-drying at -40°C for 10 hours to obtain the Henkel Algae extract, then taking 30 g of the Henkel Algae extract, adding 90 mL of water and mixing, then adjusting the pH value of the system to 8.5 with a 0.2 mol / L sodium hydroxide aqueous solution, then heating to 50°C, and then measuring 20 mL A 15wt% aqueous sodium hypochlorite solution was added dropwise within 30 minutes, and 4g of sodium bisulfite was added after the reaction was completed; then a 61wt% bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride ethanol solution was added dropwise, and after reacting for 4 hours, 0.1mol / L hydrochloric acid was added to adjust the pH to 6.5, and then the modified Sargassum henselae extract was obtained through water washing, suction filtration and drying.
[0064] Comparative Example 1
[0065] A preparation method of anti-aging PP plastic comprises the following steps:
[0066] S1 weighs 100 kg of polypropylene, 12 kg of jute fiber, 5 kg of L-ascorbyl stearate, 3 kg of calcium 2-ethylhexanoate, 4 kg of polyethylene glycol-1000, and 6 kg of diethylaminopropylamine, and adds them into a mixer and mixes and stirs them evenly at a stirring speed of 500 r / min, a mixing temperature of 140° C., and a mixing time of 30 min. After mixing evenly, a mixed material is obtained;
[0067] S2 adds the mixed material into a twin-screw extruder granulator, plasticizes and pelletizes at 155° C. to obtain the anti-aging PP plastic.
[0068] Test Example 1
[0069] The anti-aging performance of the anti-aging PP plastics prepared in Examples 1 to 5 and Comparative Example 1 was tested according to GB / T 1040.1-2018. The tensile strength 1 of the PP plastic was tested, and then the plastic was placed under a 500W ultraviolet lamp for 7 days, and then the tensile strength 2 was tested in the same way. The specific results are shown in Table 1.
[0070] Table 1 PP plastic anti-aging performance test results
[0071]
[0072] As can be seen from Table 1, Example 1 has the best anti-aging performance. Adding the composite algae extract to polypropylene plastic can play an effective anti-aging role, and its efficiency in protecting the plastic is largely determined by the polyphenols in the composite algae extract. The activity of the composite algae extract hinders the decay of free radicals involved in oxidation in the plastic. Especially when the plastic is affected by light aging, light can promote the conversion of the composite algae extract from the initial structure to a substructure with a shielding protection function. The cracking process of polypropylene under light produces a high concentration of oxidative initiators, and the composite algae extract can effectively delay and slow down degradation. The Henkel kelp extract and the salt spirulina powder in the present invention can block the reaction of free radicals converting into peroxy structures. At the same time, the stability of the composite algae extract is better than that of other natural oxidants and is not easy to degrade.
[0073] Test Example 2
[0074] The impact strength test was performed on the anti-aging PP plastics prepared in Examples 1 to 5 and Comparative Example 1. The test standard was GB / T1843-2008. The specific test results are shown in Table 2.
[0075] Table 2 Impact strength test results
[0076] <![CDATA[Impact strength KJ / M 2 > Example 1 18.4 Example 2 16.2 Example 3 15.4 Example 4 12.7 Example 5 15.8 Comparative Example 1 11.1
[0077] As can be seen from Table 2, the addition of the composite algae extract enhances the toughness of the polypropylene plastic, and in Example 1, the Henkel kelp extract is modified to introduce a carboxyl group and successfully esterified to introduce an ester carbonyl group, so that the steric hindrance inside the Henkel kelp extract changes, making the surface of the Henkel kelp extract rough and the number of holes significantly increased, which is more conducive to the compatibility of the Henkel kelp extract with the polypropylene matrix, enhances the adhesion between the two, and is beneficial to improving the impact resistance of the PP plastic.
Claims
1. An anti-aging PP plastic, characterized in that: The invention comprises the following raw materials in parts by weight: 80 to 100 parts of polypropylene, 9 to 13 parts of plant fiber, 4 to 8 parts of antibacterial agent, 1 to 4 parts of thermal stabilizer, 1 to 5 parts of dispersant, 5 to 7 parts of cross-linking agent, and 2 to 6 parts of compound algae extract; The composite algae extract is prepared by mixing modified Sargassum henselae extract and Spirulina salina powder in a mass ratio of 1:4; The modified Henkel Algae extract is prepared by the following method: weighing 80-100 g of Henkel Algae dry powder, adding a methanol-chloroform organic phase mixed solution at a solid-liquid ratio of 1:5-8 g / mL, refluxing 2-3 times with 100° C. hot water at a constant temperature, each time for 50-60 min; vacuum filtration to obtain a filtrate, rotary evaporation of the filtrate, and freeze-drying to obtain the Henkel Algae extract, then taking 20-40 g of the Henkel Algae extract and adding 80-100 mL of water to mix, then adjusting the pH value of the system to 7.5-8.5 with a 0.1-0.3 mol / L sodium hydroxide aqueous solution, then heating to 40-50° C., and then measuring 10-30 mL 15-20 wt% sodium hypochlorite aqueous solution is added dropwise within 20-30 min, and 3-5 g of sodium bisulfite is added after the reaction is completed; then 52-68 wt% of bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride ethanol solution is added dropwise, and after reacting for 2-4 h, 0.1-0.2 mol / L hydrochloric acid is added to adjust the pH to 5.5-6.5, and then the modified Sargassum henselae extract is obtained by washing with water, filtering and drying; The plant fiber is one of jute fiber and corn straw fiber; The antibacterial agent is one of N-(trichloromethylthio)phthalimide, ascorbyl stearate, and butylated hydroxyanisole; The heat stabilizer is calcium isooctanoate; The dispersant is one or more of stearic acid, polyethylene wax, liquid paraffin, and polyethylene glycol; The cross-linking agent is diethylaminopropylamine.
2. The method for preparing the anti-aging PP plastic according to claim 1, characterized in that: The preparation steps are as follows: S1 weighs polypropylene, plant fiber, antibacterial agent, heat stabilizer, dispersant, and cross-linking agent according to the formula, adds them into a mixer, mixes and stirs evenly, and the stirring speed is 400-600r / min. After mixing evenly, a mixed material is obtained; S2: the mixed material is mixed with the composite algae extract and then added into a twin-screw extruder granulator, and plasticized and pelletized at 150-160° C. to obtain the anti-aging PP plastic.
3. The method for preparing the anti-aging PP plastic according to claim 2, characterized in that: The mixing and stirring temperature in step S1 is 120-150° C., and the mixing and stirring time is 20-30 min.