CN114790309B

CN114790309B - Polyolefin composite material, preparation method thereof, floating body and photovoltaic bracket

Info

Publication number: CN114790309B
Application number: CN202210492287.9A
Authority: CN
Inventors: 汪磊; 林河山; 吴昊
Original assignee: Sunshine Water Surface Photovoltaic Technology Co ltd
Current assignee: Sunshine Water Surface Photovoltaic Technology Co ltd
Priority date: 2022-05-07
Filing date: 2022-05-07
Publication date: 2024-01-12
Anticipated expiration: 2042-05-07
Also published as: CN114790309A

Abstract

The invention discloses a polyolefin composite material, a preparation method thereof, a floating body and a photovoltaic bracket, wherein the preparation material of the polyolefin composite material comprises, by weight, 50-80 parts of a polyolefin matrix, 10-30 parts of an olefin copolymer, 8-20 parts of modified coconut fibers and 0-4 parts of an auxiliary agent. According to the invention, the polyolefin matrix and the olefin copolymer are selected as the matrix material, so that the flowability of the material is ensured, and the mechanical property of the material is improved by doping the modified coconut fiber.

Description

Polyolefin composite material, preparation method thereof, floating body and photovoltaic bracket

Technical Field

The invention relates to the technical field of polyolefin composite materials, in particular to a polyolefin composite material, a preparation method thereof, a floating body and a photovoltaic bracket.

Background

Polyolefin materials are one of the general plastics and mainly comprise higher olefin polymers such as Polyethylene (PE), polypropylene (PP) and POE, EVA, MMA. Polyethylene (PE) is in turn divided into High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE). Because of the characteristics of abundant raw materials, low price, easy processing and forming, excellent comprehensive performance and the like, the floating body is widely applied in real life, and takes a floating body applied to a water surface floating power station as an example, the floating body is used as a supporting structure to play a bearing role on a photovoltaic module, a cable, a combiner box and related equipment.

At present, the material base material adopted by the floating body is generally high-density polyethylene resin, however, the problem is that the material adopted by the existing floating body is low in melt index and cannot meet the processing conditions of injection molding, rotational molding and the like; or the melt index is higher, the mechanical properties (such as environmental stress cracking resistance, impact strength, tensile strength, rigidity and the like) are poor, and the processed product has the problems of easy cracking and the like if being used in an outdoor environment for a long time, so that the product is invalid and cannot meet the service life requirement.

The existing polyolefin material cannot give consideration to the mechanical properties and the flowability of the material, and how to improve the mechanical properties of the polyolefin material while ensuring the flowability of the polyolefin material becomes a current hot spot problem.

Disclosure of Invention

The invention mainly aims to provide a polyolefin composite material, a preparation method thereof, a floating body and a photovoltaic bracket, and aims to ensure the fluidity of the polyolefin composite material and improve the mechanical property of the polyolefin composite material.

In order to achieve the aim, the polyolefin composite material provided by the invention comprises a polyolefin matrix, an olefin copolymer, modified coconut fibers and an auxiliary agent;

wherein, the polyolefin matrix is 50-80 parts by weight, the olefin copolymer is 10-30 parts by weight, the modified coconut fiber is 8-20 parts by weight, and the auxiliary agent is 0-4 parts by weight.

Optionally, the modified coconut fiber is treated with a modifying liquid, wherein the modifying liquid comprises an organosilane coupling agent and an amphoteric surfactant.

Optionally, the coconut fiber is soaked in the modifying liquid, and the soaking time is 2-4 hours.

Optionally, the amphoteric surfactant comprises any one or more of dodecyl amino propionate, dodecyl hydroxypropyl sulfobetaine, tetradecyl hydroxypropyl sulfobetaine or dodecyl tertiary amine salt.

Optionally, the organosilane coupling agent comprises one or more of KH-550, KH-560 or KH-570.

Optionally, the organosilane coupling agent comprises one or more of KH-550 with the mass fraction of 2-3%, KH-560 with the mass fraction of 2-3% or KH-570 with the mass fraction of 2-3%, and the amphoteric surfactant comprises dodecyl tertiary amine salt with the mass fraction of 5-10%.

Optionally, the bath ratio of the modified coconut fiber to the modifying liquid is 4:10.

Optionally, the coconut fiber is dried for 1-2 hours after being treated by the modifying liquid, wherein the drying temperature is 100-140 ℃.

Optionally, the polyolefin matrix comprises one or more of high density polyethylene resin, linear low density polyethylene resin, polypropylene, and polyvinyl chloride.

Optionally, the olefin copolymer comprises one or more of butene-hexene copolymer and hexene-octene copolymer.

Optionally, the auxiliary agent comprises one or more of an antioxidant, a light stabilizer, a heat stabilizer, an anti-granule and a colorant.

The invention also discloses a floating body which is made of the polyolefin composite material according to any one of the above.

The invention also discloses a photovoltaic bracket which is made of the polyolefin composite material.

The invention also discloses a preparation method of the polyolefin composite material, which is used for preparing the polyolefin composite material and comprises the following steps:

s1, weighing raw materials according to parts by weight, and uniformly stirring the modified coconut fiber, the polyolefin matrix, the olefin copolymer and the auxiliary agent to obtain a mixture; wherein the mixing temperature is 60-90 ℃ and the mixing rotating speed is 100-300r/min;

s2, extruding and granulating the mixture to obtain first granules; the melting temperature of the extrusion granulation is 160-220 ℃;

s3, after the first granules are softened, vulcanizing and pressing to obtain the polyolefin composite material.

The invention uses polyolefin matrix as main base material in the composite material, uses olefin copolymer as auxiliary base material of the composite material, adjusts the proportion of the main base material and the auxiliary base material, and carries out compound compounding to form matrix material, thus guaranteeing the flow property of the material, and meanwhile, the incorporation of modified coconut fiber increases the mechanical property of the composite material.

Detailed Description

The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Polyolefin materials are one type of general-purpose plastic and include higher olefin polymers such as Polyethylene (PE), polypropylene (PP), and POE, EVA, MMA. Polyethylene (PE) is in turn divided into High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE).

The existing plastic products prepared by taking polyolefin materials as raw materials have the defects that the adopted polyolefin materials have low melt index and poor material fluidity, and cannot be processed by processing modes such as injection molding, rotational molding and the like; or the adopted polyolefin material has higher melt index, while the fluidity meets the processing conditions of injection molding, rotational molding and the like, the molecular weight is lower, the mechanical properties (such as environmental stress cracking resistance, impact strength, tensile strength, rigidity and the like) are poorer, and the processed product has the problems of easy cracking and the like if being used in an outdoor environment for a long time, thereby causing failure or reducing the service life.

How to improve the mechanical property of the polyolefin material while ensuring the fluidity of the polyolefin material becomes the current problem to be solved urgently.

Aiming at the problems, the invention provides a polyolefin composite material which has proper fluidity, is suitable for being processed into products under the process conditions of blow molding, injection molding, rotational molding and the like, and has better mechanical properties.

In one embodiment, the polyolefin composite is prepared from a material comprising a polyolefin matrix, an olefin copolymer, modified coconut fiber, and an adjuvant; wherein, the weight portions of the polyolefin matrix are 50-80, the olefin copolymer is 10-30, the modified coconut fiber is 8-20, and the auxiliary agent is 0-4.

In the embodiment, the polyolefin matrix is used as a main base material in the composite material, the olefin copolymer is used as an auxiliary base material of the composite material, the mixture ratio of the polyolefin matrix and the auxiliary base material is adjusted, the polyolefin matrix and the auxiliary base material are compounded into a matrix material, the flowability of the material is ensured, and meanwhile, the mechanical property of the composite material is improved by doping the modified coconut fiber.

Polyolefin matrix generally refers to the generic name of a class of thermoplastic resins obtained by the polymerization or copolymerization of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, etc., alone or in combination with certain cycloolefins, abbreviated as PO. Specifically, the polyolefin matrix may include one or more of high-density polyethylene resin, linear low-density polyethylene resin, polypropylene, and polyvinyl chloride.

The olefin copolymer refers to a copolymer obtained by copolymerizing one or more olefin monomers. In particular, the olefin copolymer may include one or more of butene-hexene copolymer, hexene-octene copolymer.

The melt index is also called melt flow index, and is a numerical value indicating fluidity of plastic materials during processing. The plastic pellets were melted into a plastic fluid and then passed through a 2.1mm diameter tube at a temperature and pressure (different standards of various materials) for a time (10 minutes) and measured in grams (g). The larger the value, the better the processing fluidity of the plastic material, and conversely, the worse.

In one embodiment, the polyolefin matrix may be selected from the group consisting of a density in the range of 0.945 to 0.965 g/cm ³ A high density polyethylene resin having a melt flow rate in the range of 0.2 to 2.5g/10min under a weight of 2.16 kg; the olefin copolymer may optionally have a density in the interval of 0.915 to 0.935g/cm ³ Butene-hexene copolymer with melt flow rate interval of 2.5-8.5g/10min under the condition of 2.16kg weight.

In one embodiment, one or more additives may be added to further improve other properties of the material, such as: antioxidants, light stabilizers, heat stabilizers, anti-shock agents, colorants, lubricants, and the like.

The light stabilizer can shield or absorb ultraviolet energy, quench singlet oxygen, decompose hydroperoxide into inactive substances and the like, so that the high polymer can eliminate or slow down the possibility of photochemical reaction under the irradiation of light, and prevent or delay the photo-aging process, thereby achieving the purpose of prolonging the service life of the high polymer product, and common light stabilizers are light stabilizer 944, light stabilizer 770, light stabilizer 622 and the like.

The anti-impact agent is also called an impact modifier, and is a chemical for improving the low-temperature embrittlement of a high polymer material and endowing the high-temperature embrittlement with higher toughness; the antioxidant applied to plastics has the function of capturing active free radicals and interrupting the chain reaction, so as to delay the oxidation process and speed of the plastics.

In the plastic material processing technology, the colorant is used as a raw material and auxiliary material to play roles in beautifying, decorating, facilitating identification, improving weather resistance, improving mechanical properties, improving optical properties and the like, and common colorants are titanium dioxide (titanium dioxide), zinc powder (zinc oxide), cadmium red, ferric oxide, carbon black, chrome yellow, zinc yellow, hansha yellow and the like.

In one embodiment, the modified coconut fiber is prepared by: and (3) soaking the coconut fiber in the modified liquid, and then filtering, drying and cooling to obtain the modified coconut fiber. The coconut fiber belongs to natural plant fiber, has the advantages of high strength, chemical corrosion resistance, environmental friendliness, no pollution and the like, is favorable for sustainable development, and is widely distributed in coastal areas and southeast Asia areas in China, and has stable supply and low cost.

The coconut fiber can be purchased directly in the market or purchased by oneself and is prepared by preprocessing the coconut fiber, wherein the preprocessing steps are as follows: soaking shredded coconut in organic solution, taking out, cleaning, drying, grinding and sieving to obtain coconut fiber; specifically, the coconut shreds are soaked in an organic solution (such as acetone) for 1-2h (so as to sufficiently remove the impregnating compound and gum impurities on the surfaces of the coconut shreds) to obtain the coconut fibers.

In this embodiment, specifically, the modified liquid includes an organosilane coupling agent and an amphoteric surfactant, and the coconut fiber can be firmly combined with the base material under the treatment of the organosilane coupling agent and the amphoteric surfactant; the organosilane coupling agent contains two groups, namely an inophilic group (concretely, an alkoxyphilic group) and an organophilic group (concretely, an amino philic group), which can be combined with hydroxyl groups in coconut fibers or long molecular chains in polymers, and the amphoteric surfactant can improve the dispersibility and the fusion degree of the organosilane coupling agent in an absolute ethyl alcohol medium, so that the reaction between the coconut fibers and the coupling agent resin is fully assisted.

Specifically, the coconut fiber is soaked in the modifying liquid for 2-4 hours generally so as to achieve the aim of complete modification, and the coconut fiber is filtered and dried after being soaked to remove the moisture in the coconut fiber so as not to influence the fusion degree of the coconut fiber and the matrix material and the performance of the composite material; in addition, the cellulose is easily affected by temperature, if the drying temperature and the drying time are controlled improperly, the structure of the cellulose can be changed or degraded, and the coconut fiber can be dried by being put into an oven at 100-140 ℃ for 1-2 hours through testing, so that the cellulose can be dried without affecting the cellulose.

In this embodiment, it is worth mentioning that the ionic surfactants commonly used in material modification are cationic surfactants and anionic surfactants; cationic surfactants have good surface activity in acidic media, while anionic surfactants are generally more suitable for forming processing with low requirements on material flowability; the coconut fiber is a mixture, is generally neutral, and can be slightly acidic due to the fact that the coconut fiber contains a small amount of pectin, and other mineral impurities can also cause the coconut fiber to be slightly acidic, and the surface active groups of the amphoteric surfactant simultaneously contain functional groups with positive charges and negative charges, so that the coconut fiber can exert better activity in different acid-base environments, can effectively reduce the surface tension of a solution, improves the reaction conversion rate of a coupling agent and the coconut fiber, and has better modification effect and wider application range. Specifically, the amphoteric surfactant can be one or more of dodecylaminopropionate, dodecylhydroxypropyl sulfobetaine, tetradecyl hydroxypropyl sulfobetaine and dodecyl tertiary amine salt; the organosilane coupling agent can be one or more of KH-550, KH-560 or KH-570.

In addition, the invention also discloses a preparation method of the polyolefin composite material, which is used for preparing the polyolefin composite material, and comprises the following steps:

In step 2, the mixture may be granulated by a twin-screw extruder, wherein the solid powder and the liquid coexist and mainly take the solid phase as the dispersion, and the self-adhesion (or the additional binder) of the dispersion is utilized to bond and enlarge the basic particles of the solid powder to each other in a forced manner (such as extrusion, gravity, centrifugal force, mechanical force, airflow impulse, etc.), and form a particle group with a certain shape and uniform particle size and concentration.

In step 3, the first pellets may be specifically melted by being carried out on a two-roll mill having a temperature of 155-165 ℃.

In addition, the invention also discloses a floating body which is made of the polyolefin composite material in any embodiment, and the floating body can be applied to the fields of marine photovoltaic power stations, pipeline or cable dredging sediment pipelines, pipeline laying and the like, and is used for the photovoltaic power stations as an example.

In the following, a specific embodiment Cheng Zuo of one embodiment of the present invention will be described in detail, taking polyethylene resin as a main base material and butene-hexene copolymer as an auxiliary base material:

first, coconut fiber (density 1.0 g/cm) ³ To 1.2g/cm ³ From 0.05mm to 0.1mm in diameter) and modified to give the modified coconut fiber described above. Wherein, the coconut fiber can be directly purchased in the market or purchased by oneself, the coconut fiber is pretreated to obtain, specifically, the purchased coconut fiber is soaked in acetone solution for 1.5 hours (removing the impregnating compound and the glue impurities on the surface of the coconut fiber), taken out and cleaned with water, and then is baked in a baking oven at 100 ℃ for 1.5 hours for drying and dehydration, and after the short sample is taken out, the coconut fiber is ground and sieved by a 100-mesh sieve, thus obtaining the coconut fiber (density is 1.0-1.2 g/cm) ³ Diameter of 0.05mm-0.1 mm).

The specific steps of modification are as follows: taking an organosilane coupling agent KH-550 with the mass fraction of 2% -3% and dodecyl tertiary amine salt with the mass fraction of 5% -10%, placing the organosilane coupling agent KH-550 and dodecyl tertiary amine salt into an absolute ethanol solution, stirring for 5 minutes, adding coconut fibers into the solution according to the bath ratio of 4:10, soaking for 3 hours, filtering, taking out, placing in an oven for drying at 100-140 ℃ for 1.5 hours, and cooling to normal temperature to obtain the modified coconut fibers, wherein the prepared modified coconut fibers have high surface activity and excellent interfacial fusion with polyethylene resin.

Embodiments of the present invention will be described in detail below with reference to specific examples, but it will be understood by those skilled in the art that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

Experiment group 1: polyethylene and butene-hexene copolymer are taken as raw materials, the mixture ratio of the polyethylene and the butene-hexene copolymer is adjusted, and the performance test is carried out on the synthesized materials, and the measured data are shown in table 1.

Table 1 preferentially identifies the range of melt flow rates for the polyethylene and butene-hexene copolymers.

As can be seen from the data in table 1, the melt index of the matrix material is related to the ratio of the polyethylene to the butene-hexene copolymer, and as the ratio of the butene-hexene copolymer increases, the melt index of the synthesized material increases, and the tensile yield stress, tensile fracture stress and fracture strain rate, that is, the mechanical properties decrease.

As can be seen from sample 1, the melt index of the butene-hexene copolymer is 1.6 (2.16 kg, (g/10 min)), and the melt index of the material is at least 1.6 (2.16 kg, (g/10 min)) or more when the material is subjected to practical processing (blow molding, injection molding, rotational molding, etc.), and the material melt index is at least 1.6 (2.16 kg, (g/10 min)) or more when the material melt index is required to satisfy the basic processing conditions, and therefore the material melt index is less than 1.6 (2.16 kg, (g/10 min)) may be disregarded.

Comprehensively considering the requirement of floating body processing equipment on the flowability of materials: the polyethylene range is determined to be 60% -80% and the butene-hexene copolymer range is determined to be 10% -30%.

Experiment group 2: modified coconut fiber is added into a certain base material ratio (polyethylene: butene-hexene copolymer=5:5), the ratio of the modified coconut fiber to a base material is changed, and performance test is carried out on the synthesized material to compare, and the measured data are shown in table 2.

TABLE 2 Performance test data of materials synthesized by changing the ratio of modified coconut fiber to matrix material when the ratio of polyethylene to butene-hexene copolymer is 5:5

Comparing the data of samples 6-9 with the materials prepared in sample 5, it can be found that the addition of modified coconut fiber can actually improve a certain mechanical property of the materials, but under the base material proportion, the mechanical property is not obviously improved, even not better than that of samples 1-4, and even the fracture strain rate is reduced when the addition proportion of modified coconut fiber is 20%.

Experiment group 3: modified coconut fiber is added into a certain base material ratio (polyethylene: butene-hexene copolymer=7:3), the ratio of the modified coconut fiber to a base material is changed, and performance test is carried out on the synthesized material to compare, and the measured data are shown in table 3.

TABLE 3 Performance test data of materials synthesized by varying the ratio of modified coconut fiber to matrix material when the ratio of polyethylene to butene-hexene copolymer was 7:3

Comparing the data of the materials prepared in samples 10-13 and 3, it can be found that, under the base material ratio, the melt index of the material is reduced, but still in an easy-to-process range, and the fluidity of the material of samples 10-12 is good, more importantly, the mechanical properties of samples 10-13 are obviously improved, especially, compared with samples 3, samples 11-13, the tensile yield stress, the tensile fracture stress and the fracture strain rate are greatly improved, and it is required to say that two to three units of improvement are greatly improved in terms of the tensile yield stress and the tensile fracture stress, and if the tensile yield stress and the tensile fracture stress of a certain material are improved to more than 5MPa, the material properties are changed, and the materials can be regarded as two different materials before and after the improvement.

Furthermore, it was found from sample 13 that the flowability of the synthesized material significantly decreased when the modified coconut fiber was added at a ratio of 20%.

And then, taking modified coconut fibers, polyethylene resin, butene-hexene copolymer and auxiliary agent, and dividing the coconut fibers or the modified coconut fibers into 10 groups according to the proportion, respectively adding the 10 groups into a high-speed mixing tank, heating and stirring, wherein the heating temperature is 60-90 ℃, the stirring speed is 100-300r/min, and mixing for 5-10min until uniformity. Granulating the uniformly mixed mixture in a double-screw extruder, wherein the double-screw extrusion temperature comprises four stages, the temperature interval of the first stage is 160-170 ℃, the temperature interval of the second stage is 175-185 ℃, the temperature interval of the third stage is 190-200 ℃, and the temperature interval of the fourth stage is 200-210 ℃.

The extruded plastic particles are further prepared into a composite material, a certain amount of particles are weighed and melted on a double-roller open mill, the temperature of the double-roller open mill is 155-165 ℃, and after the plastic particles are melted and softened, the composite material is prepared by vulcanizing and pressing.

Experiment group 4. Granulating according to the above steps to obtain composite material, melting the composite material on a two-roll mill, pressing into sample plate on a plate vulcanizing machine with a mold, and testing mechanical properties of the material according to GB/T1040.2-2006, wherein the data obtained by the test are shown in Table 4.

TABLE 4 Performance test data for different weight parts of raw materials and products synthesized from different weight parts of raw materials

Wherein, the auxiliary agents adopted in the above examples are specifically antioxidant 1010, light stabilizer UV770 and impact resistant Dow 8842; wherein, the antioxidant is 0.5 part, the light stabilizer is 0.5 part, and the anti-granule is 1 part.

From table 4, it can be seen that:

as can be seen from comparison of the data of example 1 and example 3, the mechanical properties of the materials are greatly improved after the coconut fiber is incorporated, and the melt index is reduced but still in the easy processing range.

The proportions of the polyethylene resin and the butene-hexene copolymer were changed by controlling the proportions of the coconut fiber and the auxiliary agent in examples 2, 3 and 8.

In example 3, the polyethylene resin was 80 parts, the butene-hexene copolymer was 8 parts, and the fluid flow rate of the synthesized material was only 1.2 (2.16 kg, g/10 min), and the flowability of the material was poor and the processing was difficult.

In example 3, the polyethylene resin was 70 parts, the butene-hexene copolymer was 18 parts, the flowability of the resultant material was 2.5 (2.16 kg, g/10 min) as compared with the decrease in the ratio of the polyethylene resin to the butene-hexene copolymer in example 2, the flowability was improved as compared with example 3, and it was found that the mechanical properties of the materials produced in example 2 and example 3 were not greatly changed.

In example 8, the polyethylene resin was 50 parts and the butene-hexene copolymer was 38 parts, and the fluidity of the resultant material was 5.6 (2.16 kg, g/10 min), but it was found that the mechanical properties were greatly attenuated.

By combining the test results of example 2, example 3 and example 8, it was found that the flowability was increased and the mechanical properties were decreased as the ratio of the polyethylene resin to the butene-hexene copolymer was decreased. The proportion range of polyethylene and butene-hexene copolymer between example 2 and example 8 is selected to be better in consideration of the flowability and mechanical properties of the material.

Comparing the data of examples 4, 5, 6 and 7 with the data of example 1, it can be seen that the mechanical properties of the composite material filled with the modified coconut fiber are greatly improved, the melt index is slightly reduced, but the fluidity is still better, and the composite material is in a range of easy processing.

Examples 9 and 10 are data obtained by experiments conducted on unmodified coconut fibers in examples 5 and 6, respectively, and it can be seen from table 2 that the composite material synthesized by filling the modified coconut fibers has a smaller change in the melt index value, the flowability of the material is not adversely affected, and the mechanical properties are remarkably improved.

Comparing the data of examples 1, 4, 5, 6 and 7, it is apparent that the melt flow rate is slightly reduced after the modified coconut fiber is added, but the melt flow rate is basically maintained at about 3.3 (2.16 kg, g/10 min), the fluidity of the material is good, the processing requirements of blow molding, injection molding, rotational molding and the like of the material can be fully satisfied, and more importantly, the mechanical properties (tensile yield stress, tensile breaking stress and breaking strain) of the material are obviously improved after the modified coconut fiber is added, and the mechanical properties of the polyethylene composite material are greatly enhanced by the incorporation of the modified coconut fiber.

In combination with tables 1-4, it is known that if the copolymer ratio is too high, the higher the flowability of the material, the lower the average molecular weight of the binder, which may result in no significant improvement in the overall mechanical properties of the composite, and if the cellulose is added in excess, the adverse effect may be achieved. In summary, the above embodiments comprehensively consider the types, proportions and the like of the reactants used in the polyolefin composite material, and when the polyolefin matrix ranges from 50 parts to 80 parts by weight, the olefin copolymer ranges from 10 parts to 30 parts by weight, the modified coconut fiber ranges from 8 parts to 20 parts by weight, and the auxiliary ranges from 0 part to 4 parts by weight, the synthesized material can have both fluidity and mechanical properties.

In summary, the composite material prepared by doping modified coconut fiber into a matrix material (polyolefin matrix and olefin copolymer) has excellent mechanical property and flow property; the floating body device has great support capability for lifting floating body equipment and great help for optimizing structural design, and particularly has strong competitiveness for coping with future photovoltaic floating bodies without top supports.

The foregoing is only an optional embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent structural changes made by the content of the present invention under the inventive concept of the present invention, or direct/indirect application in other related technical fields are included in the scope of the present invention.

Claims

1. A polyolefin composite material is characterized in that the preparation material comprises a polyolefin matrix, an olefin copolymer, modified coconut fibers and an auxiliary agent;

wherein, the polyolefin matrix accounts for 50-80 parts by weight, the olefin copolymer accounts for 10-30 parts by weight, the modified coconut fiber accounts for 8-20 parts by weight, and the auxiliary agent accounts for 0-4 parts by weight;

the modified coconut fiber is treated by a coconut fiber through a modifying liquid, and the modifying liquid comprises an organosilane coupling agent and an amphoteric surfactant;

the amphoteric surfactant comprises any one or more of dodecyl amino propionate, dodecyl hydroxypropyl sulfobetaine, tetradecyl hydroxypropyl sulfobetaine or dodecyl tertiary amine salt;

the organosilane coupling agent comprises one or more of 2% -3% of KH-550, 2% -3% of KH-560 or 2% -3% of KH-570, and the amphoteric surfactant comprises 5% -10% of dodecyl tertiary amine salt;

the olefin copolymer comprises one or more of butene-hexene copolymer and hexene-octene copolymer;

the polyolefin matrix comprises one or more of high-density polyethylene resin, linear low-density polyethylene resin and polypropylene.

2. The polyolefin composite of claim 1, wherein the coconut fiber is soaked in the modifying liquid for 2-4 hours.

3. The polyolefin composite of claim 1, wherein the organosilane coupling agent comprises one or more of KH-550, KH-560, or KH-570.

4. The polyolefin composite of claim 1, wherein the modified coconut fiber and the modifying liquid have a bath ratio of 4:10.

5. The polyolefin composite material according to claim 4, wherein the coconut fiber is dried for 1 to 2 hours after being treated with the modifying liquid, wherein the drying temperature is 100 ℃ to 140 ℃.

6. The polyolefin composite according to any of claims 1 to 5, wherein the auxiliary agent comprises one or more of an antioxidant, a light stabilizer, a heat stabilizer, an anti-solvent, a colorant.

7. A float, characterized in that it is made of the polyolefin composite material according to any one of claims 1 to 6.

8. A photovoltaic scaffold, characterized in that it is made of the polyolefin composite material according to any one of claims 1 to 6.

9. A process for preparing a polyolefin composite material according to any of claims 1 to 6, comprising the steps of: