KR101880487B1 - Kenaf Fiber/ Cattail Fiber/Polypropylenel Biocomposities and Method for Preparing Thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a biocomposite material using kenaf fiber / cattail fiber / polypropylene (PP), more specifically, The present invention relates to a method for producing a biocomposite material comprising a polypropylene resin.
According to the present invention, the mechanical properties and thermal deformation temperature of polypropylene alone can be remarkably enhanced by incorporating polypropylene enamel fiber / polylactic fiber through compression molding process technology, so that it can be utilized as a reinforcing material, Can be predicted to improve the process.

Description

Technical Field [0001] The present invention relates to a biocomposite using a kenaf fiber, a fibrous fiber, and a polypropylene, and a method of manufacturing the same.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a biocomposite material using kenaf fiber / cattail fiber / polypropylene (PP), more specifically, The present invention relates to a method for producing a biocomposite material composed of a natural fiber and a thermoplastic polypropylene resin.

Fiber-Reinforced Plastics (FRP) began with the addition of cellulosic fibers to the phenolic resin developed in 1908 and was subsequently applied to thermoset materials such as urea resins and melamine resins. In the 1940s, unsaturated polyester Application of FRP began to spread to ship parts, fishing equipments and daily necessities while applying glass fiber together.

However, existing composite materials contain ordinary reinforcing materials and fillers that are not readily decomposed in natural environments and are difficult to recycle when discarded after use, Therefore, the use of such fiber-reinforced polymer composite materials is increasingly restricted (T. Corbiere-Nicollier et al., Conservation and Recycling, 33: 267, 2001).

To overcome this, in 1989 Deutsches Zentrum & Luft und Raumfart Institute of Structural Mechanics of Germany introduced natural fibers such as flax, hemp and ramie into reinforcing fibers of polymer resin (AK Mohanty et al., Macromol. Mater. Eng., 1: 276, 2000).

As a kind of natural fiber, Kenaf fiber is produced in various countries having a climate of tropical region, and is cultivated at a very high speed, low cost and low density (1.42 g / cm ³ ) And the non-elasticity and the non-elasticity ratio are about the same as or slightly higher than those of the jute fiber, and generally have better color and texture than the jute fiber, and have been used for manufacturing ropes, twine, clothes and paper, In recent years, it has received the most attention in application fields of biocomposites such as automobile interior materials.

In addition, the perennial plant can be continuously produced after planting, and the production of biomass is also high, resulting in an average production of 11 ~ 15 ton / ha on average. In addition, the use of fertilizer has been reported to increase the production of biomass, which is highly regarded as an alternative biomass resource for plastics and various industrial raw materials. Unlike other cellulose-based natural fibers, the use of cattail fiber in a biocomposite system is extremely rare, so it is very encouraging to explore the possibility of using paddle fiber as a natural fiber reinforcement.

Prior art relating to such a biocomposite comprising natural fibers and polymers can be found in Korean Patent Application No. 10-2000-7004507. The patent application relates to a composite material of a resin and a cellulose or lignocellulosic fiber, and the fiber discloses a composite material comprising kenaf (claim 5) and polypropylene (claim 10) as a thermoplastic resin. In addition, Korean Patent Application No. 10-2002-7014189 discloses a prior art relating to a moldable pellet based on a composition of a natural fiber and a thermoplastic polymer. The patent application relates to a natural fiber strand comprising a majority of wound fibers and to a moldable material comprising an outer portion of a thermoplastic material, wherein the natural fiber is kenaf (claim 2) and the thermoplastic material is polypropylene 4). ≪ / RTI > However, none of these techniques discloses a configuration for improving the mechanical characteristics and the like as in the present invention.

Accordingly, in the present invention, natural fibers such as kenaf fiber / paddle fiber have been tried to be used as a reinforcing material, and as a result, the inherent characteristics of the paddle fiber and kenaf fiber produced by various processes are different from each other, And that the process can be improved by predicting the change in the properties of the natural fiber-reinforced board according to the bead fiber manufacturing method, thereby completing the present invention.

It is an object of the present invention to provide Kenaf Fiber / Cattail Fiber / Polypropylene (PP) biocomposite materials having enhanced physical properties and a method for manufacturing the same.

To achieve the above object, the present invention provides a biocomposite material comprising 25 to 35 parts by weight of kenaf fibers, 15 to 25 parts by weight of pearl fibers, and 45 to 55 parts by weight of polypropylene (PP) fibers.

The linear thermal expansion coefficient of the bio-composite is 0.38-0.65 μm / ° C. at 60-90 ° C., 0.45-0.76 μm / ° C. at 90-120 ° C., and the linear thermal expansion coefficient of the bio- Deg.] C and 130 to 150 [deg.] C, 0.68 to 1.64 [mu] m / degree Celsius, a tensile elastic modulus of 2600 to 3500 MPa, a tensile strength of 13 to 20 MPa, a flexural modulus of 2800 to 5000 MPa, and a flexural strength of 22 to 40 MPa.

(A) drying the kenaf fiber, the paraffin fiber and the polypropylene fiber at 65 to 75 ° C for 11 to 13 hours; (b) 25 to 35 parts by weight of kenaf fibers, 15 to 25 parts by weight of bundle fibers, and 45 to 55 parts by weight of polypropylene (PP) fibers; And (c) compression molding at 185 to 200 ° C at 950 to 1100 psi for 40 to 60 minutes. The present invention also provides a method for producing a biocomposite material comprising the same.

According to the present invention, the mechanical properties and thermal deformation temperature of polypropylene alone can be remarkably increased by incorporating polypropylene enamel fiber / paddle fiber through a compression molding process technique, so that it can be utilized as a reinforcing material, Can be predicted to improve the process.

In addition, natural fibers can be cultivated directly on cultivated land, and carbon dioxide (CO ₂ ) in the atmosphere is reduced while cultivated in cultivated land. Therefore, it can be eco-friendly and lightweight due to low density can be sought.

Figure 1 shows the thermogravimetric (TGA) measurements of the effect of thermal stability of Kenaf Fiber / C-CTF / Polypropylene (PP) according to four different manufacturing processes. (A: Kenaf fiber / C-CTF / PP, B: Kenaf fiber / M-CTF / PP, C: Kenaf fiber / MC1-CTF / PP, and D: Kenaf fiber / MC2-CTF / PP).
Figure 2 shows the thermal expansion behavior of four kinds of Kenaf fiber / Cattail fiber / Polypropylene (PP) (A: Kenaf fiber / C-CTF / / M-CTF / PP, C: Kenaf fiber / MC1-CTF / PP, and D: Kenaf fiber / MC2-CTF / PP).
Figure 3 shows the changes in tensile strength, tensile modulus and elongation at break for four types of Kenaf fiber / Cattail fiber / Polypropylene (PP) (A: Kenaf fiber / C CTF / PP, B: Kenaf fiber / M-CTF / PP, C: Kenaf fiber / MC1-CTF / PP, and D: Kenaf fiber / MC2-CTF / PP.
4 shows changes in flexural strength and flexural modulus for four kinds of Kenaf fiber / Cattail fiber / Polypropylene (PP) (A: Kenaf fiber / C-CTF / PP, B: Kenaf fiber / M-CTF / PP, C: Kenaf fiber / MC1-CTF / PP, and D: Kenaf fiber / MC2-CTF / PP).
5 shows changes in storage elastic modulus and tan delta value of four kinds of Kenaf fiber / Cattail fiber / Polypropylene (PP) (A: Kenaf fiber / C-CTF / PP, B: Kenaf fiber / M-CTF / PP, C: Kenaf fiber / MC1-CTF / PP, and D: Kenaf fiber / MC2-CTF / PP).
Figure 6 shows the fracture profiles of four kinds of Kenaf fiber / Cattail Fiber / Polypropylene (PP) (A: Kenaf fiber / C-CTF / PP, B: Kenaf fiber / M-CTF / PP, C: Kenaf fiber / MC1-CTF / PP, and D: Kenaf fiber / MC2-CTF / PP).
7 shows the results of a wear test of four kinds of Kenaf fiber / Cattail fiber / Polypropylene (PP) (A: Kenaf fiber / C-CTF / PP, B: Kenaf fiber / M-CTF / PP, C: Kenaf fiber / MC1-CTF / PP, and D: Kenaf fiber / MC2-CTF / PP).
Figure 8 shows the results of water absorption for four types of Kenaf Fiber / Cattail Fiber / Polypropylene (PP) (A: Kenaf fiber / C-CTF / PP, B : Kenaf fiber / M-CTF / PP, C: Kenaf fiber / MC1-CTF / PP, and D: Kenaf fiber / MC2-CTF / PP).

In the present invention, four types of cadail fiber / polypropylene (PP) biocomposite treated with Kenaf fiber / various processes are manufactured and the kenaf fiber / bundle fiber / polypropylene Biocomposite materials improved the physical properties of natural fiber reinforced board according to the manufacturing method of kenaf fiber and bundle fiber and predicted the change of characteristics of natural fiber reinforced board and utilized it as a material for improvement and reinforcement of process.

The parts may be at least one selected from the group consisting of perennial herbs and mixtures thereof belonging to the parts and the parts may be at least parts, parts, or parts.

The pretreatment process of the bundle of pile fibers of the present invention can be mechanically or chemically treated. The chemical treatment includes a step of softening the stems and leaves of the pods by an alkali treatment process (step (1)), and the softened parts Bleaching using an oxidizing agent and a reducing agent (step (2)).

In addition, the mechanical treatment is a step of making the bleached parts into a bundle of bundles of pods adjusted in length and width suitable for the use of the biocomposite. In the bleaching process, the bundle is mostly separated into bundles, but the bundle length and width Can be adjusted. High-density pulp, caliper, refiner, defibrator or other cutting machines can be used to control the length and width of the fiber bundle.

The present invention provides a biocomposite material comprising a polymer matrix and using the bundles of pearl fibers and kenaf fibers as a reinforcing material. That is, the bundle of bundle fibers and kenaf fibers can be used as a reinforcing material of a biocomposite produced by a high-temperature compression molding method by mixing with a polymer resin.

 Accordingly, in one aspect, the present invention relates to a biocomposite material comprising 25 to 35 parts by weight of kenaf fibers, 15 to 25 parts by weight of heptane fibers and 45 to 55 parts by weight of polypropylene (PP) fibers, (Wt%) is preferably 50:50. When the kenaf fiber is contained in an amount exceeding the above range, it is difficult to mix it in the production of the composite material. If the kenaf fiber is contained in the range smaller than the above range, the properties to be obtained in the present invention are not shown.

The biofabric material contained in the biofabric material is a biofabric material having i) mechanical treatment (hereinafter referred to as 'M-pod fiber'), ii) treatment with 10 to 30% NaOH (hereinafter referred to as 'C-pod fiber'), (Iii) the fibers of the invention are treated mechanically and treated with 10-30% NaOH (hereinafter 'MC1-bundle fibers'), or iv) mechanically treated with 10-30% NaOH and 2-7% Na ₂ SO ₃ (Hereinafter referred to as " MC2-bundle fiber ").

Using chemical processing units available fiber of the present invention is sufficient to use NaOH and Na ₂ SO _3, specifically, processing is as follows: a) are mixed in ethanol and an equal volume of water by volume, and hydrolysis for 1 hour; b) is dissolved in a NaOH or Na ₂ SO ₃ to the hydrolysis solution; c) immersing the mixture in the mixture for 2 hours; And d) the natural fibers are washed with distilled water and dried at 100 DEG C for 12 hours.

In the present invention, changes in the physical properties of kenaf fiber / bundle fiber / PP bio-composite material including pearl fibers treated by four different kinds of manufacturing processes are examined.

As shown in FIG. 1, as a result of measuring the thermogravimetric analysis (TGA), the overall weight loss was found to be a function of moisture, impurities, wax component Weight loss occurs at about 100 ° C, which is the temperature at which the fibers are removed, and around 280 ° C to 320 ° C and 350 ° C to 360 ° C, respectively, where decomposition of hemicellulose and cellulose, which are representative components of natural fibers, / PP The thermal stability of the biocomposite material was highest when M-padded fiber was used.

In the present invention, as a result of measurement of the coefficient of thermal expansion (CTE) of the kenaf fiber / bundle fiber / polypropylene biocomposite, the linear thermal expansion coefficient of the biocomposite is 60 to 90 ° C., 0.45 to 0.76 μm / ° C. at 90 to 120 ° C., and 0.68 to 1.64 μm / ° C. at 130 to 150 ° C., and the kenaf fiber / MC2-fiber / PP Among the four types of biocomposites, biocomposite has the best dimensional stability, which is 1.90 μm / ° C at 50 ~ 70 ° C, 1.75 μm / ° C at 70 ~ 90 ° C, Which is lower than the thermal expansion coefficient of pure polypropylene which is -6.00 μm / ° C at 100-120 ° C, and shows that the thermal expansion coefficient is stable especially at high temperature.

In one embodiment of the present invention, the tensile strength and the tensile elastic modulus of four types of kenaf fiber / bundle fiber / polypropylene biocomposite were measured. The tensile strength and the tensile elastic modulus of each sample were measured. As a result, Similarly, the bio-composite has a tensile elastic modulus of 2600 to 3500 MPa and a tensile strength of 13 to 20 MPa. The bio-composites also have higher tensile modulus and tensile strength than polypropylene.

The tensile modulus of the biocomposite composed of the kenaf fiber and the NaOH-treated C-bundle fiber showed the highest tensile modulus at 3500 MPa and the tensile modulus of the biocomposite using the M-pod fiber and kenaf fiber as the reinforcing material was 2600 MPa Respectively.

4, changes in flexural strength and flexural modulus of the kenaf fiber / paddle fiber / polypropylene biocomposite of the present invention were examined. As a result, the bio-composite showed a flexural modulus of 2800 to 5000 MPa and a tensile strength of 22 to 40 MPa , And Kenaf fiber / C-paddle fiber / PP biocomposite using NaOH treated paddle fiber and kenaf fiber had the highest flexural modulus at 5000 MPa, and flexural modulus at the lowest value The biocomposite material is Kenaf fiber / M-padded fiber / PP biocomposite material with a value of 2800 MPa.

In the present invention, as shown in FIG. 5, the storage modulus of four kinds of kenaf fiber / bundle fiber / PP biocomposite material prepared by using different kinds of fiber and kenaf fiber as reinforcement materials ) And tan δ showed that the storage elastic modulus and tan δ value of kenaf fiber / paddle fiber / polypropylene biocomposite were highly dependent on the processing method of paddle fiber, The storage modulus shows a tendency similar to that of the tensile modulus.

The storage elastic modulus of Kenaf fiber / C-paddle fiber / PP biocomposite using NaOH-treated C-pendant fiber and kenaf fiber as reinforcement is 5900 MPa, which is the highest value, and that of kenaf fiber / The fiber / PP composites have the highest tensile modulus. The lowest kinetic behavior was observed for the Kenaf fiber / M-Budle fiber / PP biocomposite material, which was made only by mechanical treatment and used as reinforcement material, and it had a storage elastic modulus of about 4300 MPa.

Fig. 6 shows the results of scanning electron microscope of the fracture profiles of four types of kenaf fiber / bundle fiber / polypropylene biocomposite of the present invention, In the case of fiber / MC1-bundle fiber / PP biocomposite, there is a small gap between the kenaf fiber and the bundle fiber and the matrix PP interface. In the case of Kenaf fibers / M-padded fibers / PP biocomposites and kenaf fibers / MC2-padded fibers / PP biocomposites, the gap and fibers escaping from the kenaf fiber and the padded fiber- The bond strength between natural fiber and matrix PP is not good.

7 shows the results of measurement of wear of four kinds of kenaf fibers / bundle fibers / PP bio-composites using pearl fibers and kenaf fibers prepared by different treatment processes of the present invention as reinforcing materials, and kenaf fibers / C -Buddle fiber / PP biocomposite showed the lowest weight loss with 0.04%, the best abrasion resistance, and Kenaf fiber / M-burdle fiber / PP biocomposite showed the greatest weight loss with 0.19% Respectively.

Fig. 8 is a graph showing the results of 30 days of water absorption test for the paddy fiber / PP biocomposite of the present invention and showing a gentle curve up to 7 days except for Kenaf fiber / M-paddle fiber / PP biocomposite And absorbed moisture.

The lowest water uptake of about 7% is due to the good bond between the fiber and the matrix, as shown in the SEM photographs. The Kenaf fiber / M-paddle fiber / PP biocomposite with the highest water uptake of 19% shows the greatest amount of water uptake due to poor interfacial bonding between the stiffener and the matrix.

In another aspect, the present invention provides a method for producing a fiber-reinforced composite fiber, comprising the steps of: (a) drying kenaf fiber, parchment fiber and polypropylene fiber at 65 to 75 占 폚 for 11 to 13 hours; (b) 25 to 35 parts by weight of kenaf fibers, 15 to 25 parts by weight of bundle fibers, and 45 to 55 parts by weight of polypropylene (PP) fibers; And (c) compression molding at 185 to 200 DEG C at 950 to 1100 psi for 40 to 60 minutes. The present invention also relates to a method for producing a biocomposite material comprising the kenaf fiber / bundle fiber / polypropylene fiber.

In order to improve the mechanical properties of bio-composites, the shape of the reinforcing material is important, and the tensile strength and flexural strength are greatly influenced by the length of the reinforcing fiber.

The compression molding process is a method of manufacturing a material in a closed mold system in which a male mold and a female mold are precisely meshed with each other in a composite material molding. When the matrix is a thermoplastic resin, a fiber and a polymer When the mixed raw material with resin compounding is put into a mold and the temperature is increased to the melting point of the matrix or more, when the resin flows and it is judged that the reinforcing material is sufficiently impregnated, the composite material is formed through the cooling process after applying the pressure.

The pearl fiber of the present invention may be characterized by being a method for producing a bio-composite material having mechanical treatment, wherein the pearl fiber is treated with 10 to 30% NaOH or 10 to 30% NaOH and 2 to 7% Na ₂ SO ₃ The method of manufacturing a bio-composite material according to the present invention.

In addition, the present invention relates to a method for producing a bio-composite material, which comprises mechanical treatment, treatment with 10 to 30% NaOH or mechanical treatment, treatment with 10 to 30% NaOH and 2 to 7% Na ₂ SO ₃ can do.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for describing the present invention in more detail and that the scope of the present invention is not limited by these embodiments in accordance with the gist of the present invention .

Example 1: Preparation of kenaf fiber / bead fiber / PP biocomposite

The kenaf fiber, the pile fiber, and the PP fiber were dried in an oven at 70 ° C for 12 hours to remove moisture completely before use. The contents of kenaf, beads and PP were 30:20:50 wt%, respectively. The fibers were uniformly mixed by hand and put into a mold, and hot-pressed at 190 ° C for 45 minutes at 1000 psi pressure To prepare a kenaf fiber / bundle fiber / PP biocomposite having a size of 150 mm x 100 mm x 5 mm. The design according to the processing method of the paddle fiber is shown in Table 1 below.

Design according to the process method of fiber design Explanation density English Korean NaOH (%) Na ₂ SO ₃ (%) C-CTF C-pod fiber Chemically-treated
Fibrous fiber 20 - M-CTF M-pod fiber Physically Treated
Fibrous fiber - - MC1-CTF MC1- Physical and chemically treated pile fibers 1 20 - MC2-CTF MC2- Physical and chemically treated pile fibers 2 15 5

Example 2: Thermal Stability Analysis

 Thermal stability and pyrolysis behavior of the kenaf fiber / bead fiber / PP biocomposite material were investigated using a thermogravimetric analyzer (TGA Q500) from TA Instruments. The temperature was increased from room temperature to 500 ° C at a rate of 10 ° C / and was measured in a nitrogen atmosphere using an alumina pan in the form of can.

As a result, as shown in Fig. 1, the kenaf fiber / M-puddle fiber / PP biocomposite started to be decomposed at the lowest temperature, followed by MC2-puddle fiber, MC1-puddle fiber and C-puddle fiber The decomposition temperature was high. In the case of kenaf fiber / M-bundle fiber / PP biocomposite, the thermal stability increased to about 390 ° C due to the inclusion of kenaf fiber. The overall weight loss can be determined at around 100 ° C, which is the temperature at which water, impurities and wax components are removed, and around 280 ° C to 320 ° C and 350 ° C to 360 ° C, respectively, where degradation of hemicellulose and cellulose, have.

Example 3: Measurement of thermal expansion

The coefficient of thermal expansion (CTE) of the kenaf fiber / bead fiber / PP biocomposite was measured using a thermomechanical analyzer (TMA 2940, TA Instruments) at a measurement temperature ranging from 30 ° C. to 150 ° C. . The heating rate was 5 ° C per minute and a standard probe (expansion probe) was used. A nitrogen gas atmosphere (nitrogen introduction rate: 50 cc / min) was measured from a probe with a load of 0.05 N applied to the specimen.

As a result, as shown in Fig. 2, the coefficient of thermal expansion at each temperature interval was the highest in the case of the kenaf fiber / M-bundle fiber / PP biocomposite material, and the coefficient of thermal expansion in the Kenaf fiber / MC1- / C-bundle fiber / PP, kenaf fiber / MC2-bundle fiber / PP bio-composite material. Kenanfibre / MC2-paddle fiber / PP biocomposite showed the lowest change of thermal expansion coefficient. Therefore, among the four types of biocomposite materials, dimensional stability is the best. The CTE values of the four kinds of bundle fibers / PP according to the processing method of the bundle fibers are shown in Table 2 below.

Example  4: Tensile test

Tensile properties of four types of padded fiber / PP biocomposite material were measured by using UTM (Shimadzu JP / AG-50kNX) according to DIN534 55, load cell was 50 kN, crosshead speed was 5 mm / min, The gauge length was measured under the condition of 100 mm.

 As a result, as shown in FIG. 3, the tensile modulus of the biocomposite composed of the kenaf fiber and the Na-treated C-pod fiber was the highest at 3500 MPa, and the tensile modulus of the M- The tensile modulus of the biocomposites using wane fiber as a reinforcing material was 2600 MPa. The bio-composites made of kenaf fiber / MC2-poured fiber exhibited lower tensile modulus than Kenaf fiber / C-pod fiber / PP biocomposite, but Kenaf fiber / M-pod fiber / PP biocomposite The tensile modulus of elasticity is higher than the tensile elastic modulus.

   In the case of tensile strength, Kenaf fiber / C-padded fiber / PP biocomposite showed a relatively high value, and Kenaf / M-padded fiber / PP biocomposite including M-padded fiber and Kenaf fiber The tensile strength was the lowest value as well as the tensile modulus.

The tensile elongation at break was relatively high for Kenaf fiber / MC1-bullite fiber / PP biocomposite, and the Kenaf fiber / M-bullite fiber / PP biocomposite material had the same tensile modulus and tensile strength at break elongation The lowest value shows that the bond strength between kenaf fiber, M-pod fiber and PP matrix is the worst.

Example 5: Flexure test

 The change in the flexural properties of the kenaf fiber / bundle fiber / PP biocomposite was investigated using UTM (Shimadzu JP / AG-50kNX) and according to ASTM D790M-86, , the span-to-depth was 16: 1, and the crosshead speed was 1.7 mm / min. The flexural strength and the modulus of elasticity were obtained from averages by measuring 10 specimens in total.

As a result, as shown in Fig. 4, kenaf fiber / C-puddle fiber / PP biocomposite using NaOH treated pearl fiber and kenaf fiber exhibited the highest bending elastic modulus at 5000 MPa, The fiber / M-padded fiber / PP biocomposite has the lowest 2800 MPa. The flexural strength was the highest at 40 MPa for Kenaf fiber / C-paddle fiber / PP biocomposite, and the lowest flexural strength at 22 MPa for Kenaf fiber / M-padded fiber / PP biocomposite . These results indicate that the kenaf fiber / C-padded fiber / PP biocomposite has the best adhesion between the matrix and the stiffener, and the kenaf fiber / M-padded fiber / PP biocomposite is the least bonded.

Example 6: Analysis of kinetic thermal characteristics

 A dynamic thermal analyzer (DMA Q800, TA Instruments) was used to investigate the kinematic thermal properties such as storage modulus and tan δ of the kenaf fiber / bundle fiber / PP biocomposite. The experiment was carried out from -40 ℃ to 100 ℃. The size of each specimen was fixed to 60 mm × 12 mm × 3 mm, and the rate of temperature rise was 2 ° C. per minute. The specimens underwent a sinusoidally oscillating frequency dynamically in a dual cantilever mode. The frequency was fixed at 1 Hz and the oscillation amplitude was kept constant at 0.15 mm.

As a result, as shown in FIG. 5, the storage elastic modulus and the tan delta value of the kenaf fiber / bundle fiber / PP biocomposite material were highly dependent on the processing method of the fiber, and the storage elastic modulus tended to be similar to the result of the tensile elastic modulus .

The storage elastic modulus of the kenaf fiber / C-paddle fiber / PP biocomposite using NaOH-treated C-pendant fiber and kenaf fiber as reinforcement was the highest at 5900 MPa and the highest tensile modulus Respectively. The lowest dynamic properties were observed for the Kenaf fiber / M-bundle fiber / PP biocomposite, which was made only by mechanical treatment and fiber reinforced with kenaf fiber, and exhibited a storage elastic modulus of about 4300 MPa. The storage elastic modulus of Kenaf fiber / MC1-padded fiber / PP biocomposite and Kenaf fiber / MC2-padded fiber / PP biocomposite were 5200 MPa and 5800 MPa, respectively.

The tan δ peak intensity did not depend on the type of pearl fibers and the addition of kenaf fibers, and the position of the tan δ peak did not change much, but the Kenaf fiber / MC1-pearl fiber / PP biocomposite It was confirmed that a peak was observed at a temperature as low as 5 캜.

Example 7: Microstructure and fracture surface observation

Scanning Electron Microscope (SEM, JEOL JSM 6380) was used to observe the fracture surface and fiber-resin bonding state of the kenaf fiber / bundle fiber / PP biocomposite. In order to impart conductivity to the surface of all specimens used for the measurement, the surface of the specimen prepared by sputtering for a certain period of time was coated once with platinum (Pt) for about 3 minutes and observed. The fracture specimens of the kenaf fiber / bundle fiber / PP biocomposite were obtained after tensile test, and the fracture observation focused on one bundle of bundles of fibers wrapped by the PP matrix.

As a result, as shown in FIG. 6, in the case of Kenaf fiber / C-puddle fiber / PP biocomposite and Kenaf fiber / MC1-puddle fiber / PP biocomposite, Kneaf fibers / M-padded fibers / PP biocomposites and Kenaf fibers / MC2-padded fibers / PP biocomposites are formed on the interface between the kenaf fiber and the paddle fiber and the matrix PP. It was confirmed that the bonding strength between the natural fiber and the matrix PP is not good due to the fact that the gap and the fiber are missing.

Example 8: Measurement of abrasion resistance

 The abrasion resistance of the kenaf fiber / bundle fiber / PP biocomposite material was measured in accordance with ISO 2231. The exposed specimens were exposed to air in a constant temperature and humidity atmosphere at a temperature of 20 ° C and a humidity of 50% When the difference was less than 0.1%, the specimen was considered to be in equilibrium state. The abrasion tester of the QM600T model of Qmesys was used, and Taber's standard wear wheel H-10 was used. The weight of the weight applied to each specimen was measured to be 1000 g, the rotational speed was 30 rpm, and the number of revolutions was 900.

As a result, as shown in FIG. 7, the kenaf fiber / C-puddle fiber / PP biocomposite material having the best bending property and tensile property showed the lowest weight loss of 0.04% and the abrasion resistance was the best. Kenaf fiber / M-Budle fiber / PP biocomposite showed the biggest weight loss with 0.19%. Kenav fiber / MC1-padded fiber / PP biocomposite and Kenaf fiber / MC2-padded fiber / PP biocomposite showed a similar weight loss of 0.15%. This result shows that the kenaf fiber / M-padded fiber / PP biocomposite material is damaged due to mechanical damage due to mechanical treatment and is damaged by the abrasion load during the test. This means that the wear rate has increased due to the weight loss caused by falling off.

Example 9: Measurement of water absorption

To investigate the water absorption of the kenaf fiber / bead fiber / PP bio-composite material, the weight change was measured once a day and immersed in a 3000 mL beaker containing distilled water for a total of 30 days. The size of the immersed specimen was 135 mm in length, 15 mm in width, and 5 mm in thickness. The immersion beaker temperature was maintained at 25 ° C. throughout the measurement period. Moisture absorbency data are shown as averages of five specimens.

 As a result, as shown in Fig. 8, except for Kenaf fiber / M-pod fiber / PP biocomposite material, the curve showed a gentle curve until day 7 and absorbed moisture. Kenaf fiber / M-pod fiber / PP Biocomposites absorbed a great deal of water up to the third day and then absorbed water constantly. Kenaf fiber / C-budulite fiber / PP biocomposite absorbed 7% Water absorption. This result implies that the kenaf fiber has inherently lower water absorbency than the weft fiber.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereto will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (14)

Wherein the linear thermal expansion coefficient is in the range of 0.38 to 0.65 占 폚 / ° C, 90 to 120 占 폚 at 60 to 90 占 폚, 25 to 35 parts by weight of the kenaf fiber, 15 to 25 parts by weight of the bundle fibers, and 45 to 55 parts by weight of the polypropylene ° C, 0.68 to 1.64 μm / ° C at 130 to 150 ° C, a flexural modulus of 2800 to 5000 MPa, and a flexural strength of 22 to 40 MPa.
The bio-composite material according to claim 1, wherein the bundle fibers are mechanically treated to control the length and width of the fiber bundle.
The bio-composite material according to claim 1, wherein the bundle fibers are treated with 10 to 30% NaOH.
The bio-composite material according to claim 1, wherein the helix fiber is treated with 10 to 30% NaOH and 2 to 7% Na ₂ SO ₃ .
The bio-composite material according to claim 1, wherein the bundle fibers are mechanically treated to adjust the length and width of the fiber bundles and treated with 10 to 30% NaOH.
The bio-composite material according to claim 1, wherein the heptane fibers are mechanically treated to adjust the length and width of the fiber bundles, and are treated with 10 to 30% NaOH and 2 to 7% Na ₂ SO ₃ .
The bio-composites according to claim 1, wherein the bio-composites have a tensile modulus of 2600 to 3500 MPa and a tensile strength of 13 to 20 MPa.
delete A method for producing a bio-composite material comprising a kenaf fiber / bundle fiber / polypropylene fiber comprising the steps of:
(a) a paddle fiber, a kenaf fiber and a polypropylene fiber which are mechanically treated to control the length and width of the fiber bundle and treated with 10 to 30% NaOH and 2 to 7% Na ₂ SO ₃ at 65 to 75 ° C Drying for 11 to 13 hours; (b) 25 to 35 parts by weight of kenaf fibers, 15 to 25 parts by weight of bundle fibers, and 45 to 55 parts by weight of polypropylene (PP) fibers; And (c) compression molding at 185 to 200 DEG C for 9 to 1100 psi for 40 to 60 minutes. delete delete delete delete delete

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