KR101601225B1 - Resin composition for biocomposites, preparing the same, and molded product - Google Patents

Abstract

The present invention relates to a resin material comprising a polypropylene resin and a polylactic acid resin; And
A resin composition for a biocomposite material comprising an additive including natural fibers, wherein the natural fiber has O-Si-O bonds connected to the surface of the natural fiber from which lignin and hemicellulose contained therein are removed, and A process for producing the same, and a molded article produced therefrom.

Description

 TECHNICAL FIELD [0001] The present invention relates to a resin composition for a biocomposite, a method for producing the same,

The present invention relates to a resin composition for a biocomposite, a method for producing the same, and a molded article comprising the same.

Glass fiber reinforced plastics or polymer composites have been used to improve the properties of composites in automotive and industrial composite materials, but these materials are not environmentally friendly and are an important source of environmental pollution.

On the other hand, a composite material added with natural fibers is recently called a green composite material or a biocomposite material and is widely known to be widely applicable to automobile parts material, construction / civil engineering field, and life material field.

However, since the natural fibers are not easily mixed in the melt extrusion process used for producing a composite material with resin due to the extremely low density compared to the widely used fiberglass which is widely used in industry, the feeding of the material in the feeder during extrusion is quantitatively smoothly introduced So that normal extrusion processing can not be performed in many cases. Due to these problems, the physical properties of the final composite are very wide and there is a fundamental disadvantage that the filling amount of the fibers can not be increased. In addition, since the surface polarity of natural fibers is mostly hydrophilic, the surface adhesion with the resin material is very low, and the physical properties of the natural fibers are very poor in terms of impact strength and the like. In addition, the lignin components contained in the natural state include the problems of odor generation and the problem of water spraying in the final composite.

In the case of Korean Patent Laid-Open No. 10-2009-0058374, which relates to a method for producing a polylactic acid / natural fiber composite material, a polylactic acid / natural fiber composite board is produced by carding, web forming, , And a method of producing a poly (lactic acid) / natural fiber composite material in the form of a chip by cutting the same is disclosed in which a fibrous material is mixed and a board is formed by a compression molding method, followed by pulverizing it into pellets.

However, the composite material produced in the above-described manner has a physical property range that can not replace the currently widely used injection molded polypropylene composite material, and is costly in terms of cost because it has to be radiated in a fiber state.

In the case of Korean Patent Laid-Open No. 10-2010-0055335, a first polylactic acid resin; And natural fibers surface-treated with a second poly (lactic acid) resin, wherein the second poly (lactic acid) resin comprises isomers different from the first poly (lactic acid) resin, or quenched to a crystallization temperature at 240 & The present invention provides a natural fiber-reinforced poly (lactic acid) resin composition and a molded article using the same, wherein spherulite crystals are formed on the surface of a natural fiber before a surface of the natural fiber and have a higher growth rate at the time of observation, And a method of using the same. However, the technology described above is a technique in which the composition of the resin material is limited to polylactic acid, and the surface of the natural fiber is controlled by the polylactic acid, so that the natural fiber itself is not chemically treated and introduced. Therefore, The fundamental disadvantages of the fibers may not be solved.

One aspect of the present invention provides a resin composition for a biocomposite material in which chemically treated natural fibers are introduced to simultaneously satisfy physical properties of heat resistance, impact resistance, high tensile strength, and flexural strength.

Another aspect of the present invention provides a method for producing the resin composition for a biocomposite.

Another aspect of the present invention provides a molded article produced from the resin composition for a biocomposite.

One embodiment of the present invention relates to a resin material comprising a polypropylene resin and a polylactic acid resin; And

An additive comprising natural fibers,

The natural fiber is obtained by removing the lignin and hemicellulose contained therein, and provides a resin composition for a biocomposite including an O-Si-O bond connected to the surface of the natural fiber.

The O-Si-O bond connected to the surface of the natural fiber may exhibit hydrophobicity.

The lignin may be removed in an amount of 30 to 50% by weight based on the total amount of the natural fibers.

The hemicellulose may be 5 to 10% by weight of the total amount of the natural fibers.

The average length of the natural fibers may be 0.01 to 100 mm.

The average diameter of the natural fibers may be 0.001 to 50 mu m.

Wherein the resin material comprises 80 to 93% by weight of the polypropylene resin and 7 to 20% by weight of the polylactic acid resin,

The natural fibers may be included in an amount of 10 to 20 parts by weight based on 100 parts by weight of the resin material.

The polylactic acid resin and the natural fiber may contain 25 wt% or more of the total amount of the resin composition for a biocomposite.

The additive may further include at least one of an impact reinforcement, a compatibilizer, a stabilizer, a hydrolysis inhibitor, an antioxidant, a pigment, and a dye.

The impact reinforcing material may be a copolymer including a butyl (meth) acrylate monomer and a glycidyl (meth) acrylate monomer in a polyethylene skeleton.

The impact reinforcing material may be an ethylene copolymer having a skeleton represented by the following general formulas (1) and (2).

[Chemical Formula 1] < EMI ID =

In Formula 1, m and n are each independently a natural number.

The impact reinforcing material may be included in an amount of 3 to 7 parts by weight based on 100 parts by weight of the resin material.

The melt index (MI) of the impact reinforcing material may be 2 to 10 g / 10 min.

The compatibilizer may be a maleic anhydride graft polypropylene resin.

The maleic anhydride may be grafted to the polypropylene resin in an amount of 0.1 to 5% by weight.

The compatibilizing agent may be included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the resin material.

The poly (lactic acid) resin may be selected from L type poly (lactic acid) resin, D type poly (lactic acid) resin, and combinations thereof.

The polypropylene resin may have a melt index (MI) of 10 to 40 g / 10 min.

The melt index (MI) of the poly (lactic acid) resin may be 5 to 40 g / 10 min.

Another embodiment of the present invention is a method for producing a polypropylene resin, comprising the steps of: preparing a mixture of a polypropylene resin and a polylactic acid resin;

Treating the natural fiber with an alkali solution to remove lignin and hemicellulose contained in the natural fiber;

Washing the natural fiber from which the lignin and hemicellulose have been removed with water, neutralizing it by immersing it in an acid solution, removing the water contained therein, and drying the natural fiber; And

After the neutralized and dried natural fibers were coated with a silane compound and adsorbed thereon, 110 To a mixture of the polypropylene resin and the poly (lactic acid) resin, and a step of subjecting the dried natural fiber to a vacuum treatment at a temperature of 100 to 130 DEG C to induce a chemical reaction on the surface of the dried natural fiber, .

The concentration of the alkali solution may be from 5% to 15%.

The content of the natural fiber contained in the alkali solution 1L may be 10 g to 30 g.

The pH of the acid solution may be 3.5 to 4.5.

The acidic substance contained in the acid solution may be lactic acid.

The silane-based compound may be selected from aminosilane, vinylsilane, epoxy silane, and mixtures thereof.

Another embodiment of the present invention provides a molded article produced from the resin composition for a biocomposite as described above.

A chemically processed natural fiber is introduced, and a composition for a biocomposite material which is environmentally friendly and which simultaneously satisfies the physical properties of heat resistance, impact resistance, high tensile strength and bending strength can be realized, and a molded article manufactured therefrom can be realized.

FIG. 1 is a schematic view for explaining a method of manufacturing a composition for a biocomposite according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains.

The present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

As used herein, unless otherwise specified, "(meth) acrylate" means that both "acrylate" and "methacrylate" are possible. (Meth) acrylate " means " glycidyl acrylate "and" glycidyl (meth) acrylate "Quot; and " sidyl methacrylate "

The resin composition for a biocomposite according to one embodiment of the present invention is a resin composition for a biocomposite,

A resin material comprising a polypropylene resin and a polylactic acid resin; And

An additive comprising natural fibers,

The natural fiber may contain O-Si-O bonds connected to the surface of the natural fiber from which lignin and hemicellulose contained therein are removed.

The polylactic acid resin and the natural fiber are components derived from a biomass, and the resin composition for a biocomposite according to an embodiment of the present invention contains the biomass-derived component in an amount of 25 wt% or more of the total amount of the resin composition for a biocomposite Materials that meet the biomass plastic marking scheme can be implemented.

Biomass Plastics is a polymeric material made by chemically or biologically synthesizing substances derived from organisms such as plants and animals derived from living organisms and by-products associated therewith,

The biomass plastic mark system does not include prohibited substances separately determined from the total components of biomass plastics in order to emphasize the importance of prevention of global warming and reduction of consumption of fossil raw materials and contains biomass derived components in an amount of 25 wt% Is a system that gives a mark indicating that it is an eco-friendly material.

Hereinafter, each component included in the resin composition for a biocomposite according to one embodiment of the present invention will be described in detail.

Resin material

The resin material according to one embodiment of the present invention may include a polypropylene resin and a poly lactic acid resin.

Hereinafter, each resin component will be described in detail.

(A) Polypropylene resin

The polypropylene resin is a polymer synthesized from petroleum resources and is characterized by being homo or block copolymer. The melt index (MI) measured at 230 ° C under a load of 2.16 kg may be 10 to 40 g / 10 min . If the melt index is less than 10 g / 10 min, there is a problem of overhead of processing due to an increase in melt viscosity. If the melt index exceeds 40 g / 10 min, there is a problem in melt-blending extrusion processing due to a low melt point.

The polypropylene resin may be contained in an amount of 80 to 93% by weight of the total amount of the resin material. If the content of the polypropylene resin is less than 80% by weight, the mechanical properties may deteriorate. If the content is more than 93% The content of the biomass-derived component required is out of the range.

(B) Poly lactic acid  Suzy

The poly lactic acid resin is a biomass-derived component, and its main use until now is a disposable product using the biodegradability of polylactic acid, for example, a food container, a wrap, a film and the like.

The poly lactic acid resin may be selected from L type poly lactic acid resin, D type poly lactic acid resin, and a combination thereof.

The L-type poly (lactic acid) resin may be represented by the following formula (3), and the D-type poly (lactic acid) resin may be represented by the following formula (3).

(3)

In Formula 3, l is a natural number.

The polylactic acid resin may be a starch and biomass-derived polymer and has a melt index (MI) of 5 to 40 g / 10 min measured at 190 ° C under a load of 2.16 kg. If the melt index is less than 5 g / 10 min, there is a problem in overhead of processing due to an increase in melt viscosity. If the melt index exceeds 40 g / 10 min, there is a problem in melt-blending extrusion due to a low melt point.

The polylactic acid resin may be contained in an amount of 7 to 20% by weight based on the total amount of the resin material. If the content of the poly (lactic acid) resin exceeds 20% by weight, mechanical property deterioration may occur. If the content of the poly (lactic acid) resin is less than 7% by weight, the content of the biomass-

additive

The additive according to one embodiment of the present invention may include natural fibers in which lignin and hemicellulose contained therein are removed and O-Si-O bonds are present on the surface.

The additive may further include at least one of an impact reinforcement and a compatibilizing agent in addition to the above-mentioned natural fibers.

Hereinafter, each component contained in the additive will be specifically described.

(A) Natural fibers

The natural fiber has a specific gravity of about 1.1 to about 1.5, which is only about 50 to 60% of the glass fiber widely used in the industrial field, and can be completely biodegraded in nature. Therefore, when applied to a composite material, Can be pursued. In addition, natural fibers absorb large quantities of carbon dioxide present in the atmosphere during cultivation and growth and release oxygen, thereby contributing to the prevention of global warming. In particular, since natural fibers can be recycled unlike glass fibers and synthetic fibers, and they do not increase the atmospheric carbon dioxide concentration even after incineration, natural fiber-reinforced composite materials are more resistant to inorganic materials or metal- And it is expected to play a more efficient role.

Natural fibers grown in the natural state may include flax, hemp, jute, kenaf, ramie, curaua, and the like,

Cellulosic natural fibers such as jute, kenaf and the like of the natural fibers contain cellulose in an amount of 70% by weight or more, and the cell membrane of the fibrous cell is mainly composed of cellulose, lignin and hemicellulose, ≪ / RTI >

However, since the lignin component includes a problem of odor generation in the final composite material and a problem of the water-based granulation, it may cause a problem of discoloration of the final molded product due to pyrolysis in the molding process, and the hemicellulose component has a low reinforcing effect on rigidity, And the mechanical strength can be reduced.

In addition, since the natural fibers are not easily mixed in the melt extrusion process, which is used for producing a composite material with a resin due to a remarkably low density compared to glass fiber widely used in industry, the feed of the material in the feeder can be quantitatively introduced And the extrusion process can not be normally performed. In this case, the dispersion of physical properties of the final composite material is very wide, and there is a fundamental disadvantage that the filling amount of the fiber can not be increased. In addition, since the surface polarity of natural fibers is mostly hydrophilic, the surface adhesion with the resin material is very low, and the physical properties of the natural fibers are very poor in terms of impact strength and the like.

In order to overcome this problem, the natural fiber according to an embodiment of the present invention is treated with an alkali solution to remove lignin and hemicellulose contained therein, and the surface of the natural fiber is treated with a silane compound to remove O By forming the -Si-O bond, natural fibers having hydrophobicity induced on the surface of the natural fiber can be used.

That is, the natural fiber according to one embodiment of the present invention can be prepared by a method of chemically removing the lignin component and the hemicellulose component. Specifically, the lignin component is removed in an amount of 30 to 50 wt% based on the total amount of the natural fibers, and the hemicellulose component may be removed in an amount of 5 to 10 wt% based on the total amount of the natural fibers. When the content of lignin and hemicellulose is removed by the above amount, the problem of odor generation of the final composite material and the problem of discoloration of the molded product due to pyrolysis of lignin during molding are not caused, and the hemicellulose component having low stiffness reinforcing effect is removed from the final composite Ultimately, the cellulose content is increased, so that heat resistance and mechanical strength can be improved.

Subsequent steps can then be performed to chemically surface the natural fibers from which the lignin and hemicellulose components have been removed.

In general, since hydrophilic functional groups such as hydroxyl groups (-OH) are present on the surface of natural fibers, it is difficult to expect high adhesion strength with resin materials that are mostly hydrophobic.

The natural fiber according to the present invention can induce hydrophobicity on the surface of the natural fiber by treating a hydrophilic functional group present on the surface, such as a hydroxyl group, with a silane compound.

Specifically, the oxygen atom of the hydroxyl group present on the surface of the natural fiber becomes a mediator, and the surface of the natural fiber can be connected to the O-Si-O bond derived from the silane compound. The remaining two Si atoms in the O-Si-O bond may be hydrogen, a vinyl group, an epoxy group, or the like.

The natural fiber having hydrophobicity induced on the surface has a high surface adhesion with the resin material, so that the impact strength of the final composite material can be improved. Since the surface polarity is changed to be hydrophobic, moisture absorption is blocked, so that it is possible to obtain an advantageous effect also in terms of long-term storage.

The natural fiber may have an average length of 0.01 to 100 mm, and more specifically 0.1 to 10 mm. When the thickness is less than 0.01 mm, the effect of reinforcing the physical properties may be insufficient after the composite material is manufactured. If the thickness is 100 mm or more, the uniformity of properties after the final composite material may be lowered.

The natural fibers may have an average diameter of 0.001 to 50 탆, and more preferably 10 to 20 탆. When the average diameter is 0.001 탆 or less and 50 탆 or more, the dispersibility in the final composite material is lowered and the effect of improving the physical properties is insufficient.

That is, when the average length and the average diameter of the natural fibers are within the above ranges, improvement in mechanical strength such as tensile strength, flexural strength, flexural modulus and the like and excellent workability and appearance characteristics can be exhibited.

The natural fibers may be included in an amount of 10 to 20 parts by weight based on 100 parts by weight of the resin material.

If the content of the natural fiber is less than 10 parts by weight, improvement of mechanical properties and heat resistance is insufficient. If it exceeds 20 parts by weight, some stiffness is increased and non-uniformity of deteriorating some physical properties is increased, do. In particular, when the content of the natural fiber is the same as above, the 'content of the biomass-derived component' representing the content of the natural fiber and the polylactic acid resin in the total amount of the resin composition for a biocomposite according to an embodiment of the present invention is 25 weight %, It is possible to realize eco-friendly materials that conform to the biomass plastic mark system.

(B) Impact reinforcement

The impact modifier may include a butyl (meth) acrylate monomer and a glycidyl (meth) acrylate monomer in the polyethylene skeleton.

Specifically, it may be an ethylene copolymer containing a skeleton represented by the following general formulas (1) and (2).

[Chemical Formula 1] < EMI ID =

In the above formulas (1) and (2), m and n are each independently a natural number.

For example, the impact reinforcement may be poly (ethylene-n-butyl acrylate-glycidyl methacrylate, where the normal butyl acrylate is 7 to 15 wt% and the glycidyl methacrylate is 3 to 7 wt% %, Most specifically 10% by weight of n-butyl acrylate and 5% by weight of glycidyl methacrylate.

The impact stiffener may contain a butyl acrylate chain and a glycidyl methacrylate chain as a side chain in the polyethylene main chain as shown in the above formulas (1) and (2). The butyl acrylate enhances the interfacial adhesion between the impact modifier and the polypropylene. The glycidyl methacrylate improves the compatibility of the impact modifier with the poly (lactic acid) and enhances the compatibility with the glass fiber . Therefore, it is presumed that the impact stiffener has a property of increasing the interfacial adhesion between each composition of the composite material.

The impact reinforcing material may be included in an amount of 3 to 7 parts by weight based on 100 parts by weight of the resin material. If the content of the impact modifier is less than 3 parts by weight, the effect of improving the impact strength is remarkably reduced, so that it can not be applied to automobile parts. When the amount exceeds 7 parts by weight, the impact strength is excessively improved and the heat resistance is lowered. There is a disadvantage that the field is limited.

The melt index (MI) of the impact modifier measured at 190 占 폚 under a load of 2.16 kg may be 2 to 10 g / 10 min.

(C) a compatibilizer

The compatibilizing agent may be an additive which serves to strengthen the polylactic acid resin, the polypropylene resin, and the contact portion of the glass fiber, and may be a maleic anhydride graft polypropylene resin. Specifically, a polypropylene resin having a weight average molecular weight (Mw) of 50,000 to 250,000 g / mol, grafted with maleic anhydride units of 0.1 to 5% by weight can be used.

The compatibilizing agent may be included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the resin material. Specifically, it is preferable to use about 10 to 20 parts by weight per 100 parts by weight of the poly (lactic acid) resin. When the ratio is less than the minimum value, the appropriate interfacial adhesion can not be obtained. If the ratio exceeds the maximum value, the content of the maleic anhydride-grafted polypropylene resin having a different polarity from the polypropylene resin is increased, The physical properties may be deteriorated.

(D) Other additives

If necessary, it may further include at least one of stabilizers, hydrolysis inhibitors, antioxidants, pigments, and dyes in addition to the above additives.

A method for producing a resin composition for a biocomposite material according to another embodiment will be described in more detail below.

A resin composition for a biocomposite material, comprising: preparing a mixture of a polypropylene resin and a polylactic acid resin; Treating the natural fiber with an alkali solution to remove lignin and hemicellulose contained in the natural fiber; Washing the natural fiber from which the lignin and hemicellulose have been removed with water, neutralizing it by immersing it in an acid solution, removing the water contained therein, and drying the natural fiber; And applying and adsorbing a silane compound on the neutralized and dried natural fibers, followed by a vacuum treatment at a temperature of 110 to 130 ° C to induce a chemical reaction on the surface of the dried natural fibers, To the mixture of lactic acid resin.

Polypropylene resin, and polylactic acid resin may be prepared by melting and kneading at a temperature of 180 to 190 캜.

In the step of mixing the chemically treated natural fiber, the polypropylene resin, and the polylactic acid resin, additives other than natural fibers may be further mixed.

Specifically, additives such as natural fibers, impact reinforcements and compatibilizers chemically treated with a mixture of the polypropylene resin and the poly (lactic acid) resin are introduced using an extruder mixing head, a side feeding device and a continuous kneader, Lt; RTI ID = 0.0 > of < / RTI >

If the stirring and mixing temperature is less than 180 ° C, stirring and mixing may not be sufficiently performed. If the temperature exceeds 190 ° C, some natural fibers may be thermally decomposed.

In the chemical treatment method of the natural fibers, the concentration of the alkali solution may be 5% to 15%. When the concentration of the alkali solution is 5% or less, lignin and hemicellulose are not completely removed at the desired ratio, and if it is 15% or more, damage may occur to some surfaces of the cellulose.

The content of the natural fiber contained in the alkali solution 1L may be 10 g to 30 g. When the ratio of the alkali solution to the natural fiber is 10 g / L or less, damage is caused to a part of the surface of the cellulose. When the ratio is 30 g / L or more, lignin and hemicellulose are not completely removed at the desired ratio . On the other hand, the natural fibers can be treated in an alkali solution for about 2 to 4 hours.

The most specific example of the alkali solution includes, but is not limited to, a sodium hydroxide solution.

The alkaline solution-treated natural fiber can be immersed in the acid solution to neutralize the remaining alkali component, and at the same time, the alkaline components present in the natural fiber can be removed as much as possible. After the alkali solution treatment, washing with water before immersion in the acid solution may be carried out several times.

The pH of the acid solution may be 3.5 to 4.5. When the pH is less than 3.5, there is a problem that the acidity of the acid material in the fiber increases and the physical properties of the final composite material deteriorate. In contrast, when the pH is more than 4.5, the alkali component can not be sufficiently removed, May affect the physical properties of the final composite.

Examples of the acidic substance contained in the acid solution include acetic acid, hydrochloric acid, and lactic acid. Particularly, in the case of treatment with lactic acid, lactic acid is a basic substance to be used as a raw material of polylactic acid, so that when the lactic acid partially remains on the surface of the natural fiber, the interfacial adhesion force with the resin material in the composite material production step can be further improved.

However, the acidic substance contained in the acid solution is not limited thereto.

The surface of the natural fiber can be connected to the O-Si-O bond by inducing the chemical reaction between the hydroxyl group and the silane compound present on the surface of the natural fiber by applying and adsorbing the silane compound on the neutralized and dried natural fiber.

The silane-based compound may be selected from aminosilane, vinylsilane, epoxy silane, and mixtures thereof. Particularly, when epoxy silane is applied, the polylactic acid resin and the impact reinforcement contained in the resin material contain a methacrylate component, so that the interface interaction between the epoxy resin and the methacrylate is maximized due to the strong chemical reaction between the epoxy silane and the methacrylate So that epoxy silane is more preferable.

The silane compound may be applied alone or in a solvent such as ethanol to be applied and adsorbed.

The molded article according to another embodiment of the present invention can be produced by subjecting the above-described resin composition for a biocomposite material to a general injection molding machine by a specimen or a component injection molding.

(Chemical treatment of natural fibers)

Manufacturing example  One

25 g of jute as natural fiber was added to 1 L of 10% sodium hydroxide solution, stirred for 2 hours, and contacted. And then washed 2-3 times with water.

The alkali-treated natural fibers were washed three times with water and then neutralized by immersion in a solution of lactic acid at pH 3.5.

The treated natural fibers were dried while removing water contained therein. Then, the dried natural fibers are put into a reactor capable of controlling the vacuum and temperature to apply epoxy silane, Lt; 0 > C and a vacuum condition for about 2 hours. Since 100 Lt; 0 > C for about 20 hours to prepare chemically treated natural fibers.

The average length of the chemically treated natural fibers was 50 mm and the average diameter was 10 탆.

Manufacturing example  2

Natural fibers chemically treated were prepared in the same manner as in Preparation Example 1, except that kenaf was used instead of jute as a natural fiber.

Comparative Manufacturing Example  One

The natural fibers of Preparation Example 1 were used without chemical treatment of the natural fibers.

Comparative Manufacturing Example  2

25 g of jute as natural fiber was added to 1 L of 10% sodium hydroxide solution, stirred for 2 hours, and contacted. And then washed 2-3 times with water.

The alkali-treated natural fibers were washed with water three times, then immersed in a lactic acid solution of pH 3.5 to neutralize them, and then dried to prepare alkali-treated natural fibers.

(Production of Resin Composition for Biomaterials)

Example  One

80% by weight of a polypropylene resin (product name: BI830, product name: BI830) and 20% by weight of L-type polylactic acid resin (Nature Works, Ingeo 3251D) were kneaded in a dry state, Kneaded to prepare a mixture of polypropylene resin and poly (lactic acid) resin. Then, 5 parts by weight of an impact reinforcement (Elvaloy PTW) was added to 100 parts by weight of the mixture at the mixing head portion, 12 parts by weight , And 3 parts by weight of a compatibilizing agent (maleic anhydride-grafted polypropylene, product of Lotte Chemical Co., Ltd., product name: PH-200).

Example  2

A mixture was prepared using 85% by weight of a polypropylene resin (product of Samsung Total, product name: BI830) and 15% by weight of L-type poly (lactic acid) resin (Nature Works, Inc., Ingeo 3251D). 17 parts by weight of the natural fiber of Preparation Example 1 The composition was prepared in the same manner as in Example 1, except that the composition was used.

Example  3

A mixture was prepared using 90 weight% of a polypropylene resin (product of Samsung Total, product name: BI830) and 10 weight% of an L-type poly (lactic acid) resin (Nature Works, Inc., Ingeo 3251D), and 7 parts by weight of the above- A composition was prepared in the same manner as in Example 1, except that 20 parts by weight of the natural fiber of Example 1 was used.

Comparative Example  One

A composition was prepared in the same manner as in Example 3, except that the natural fiber of Comparative Preparation Example 1 was used.

Comparative Example  2

A composition was prepared in the same manner as in Example 3, except that the natural fiber of Comparative Preparation Example 2 was used.

The composition of the resin composition for a biocomposite is as shown in Table 1 below.

division Example Comparative Example One 2 3 One 2 Resin material
(weight%) (A) 80 85 90 90 90 (B) 20 15 10 10 10 additive
(Parts by weight) (C) 5 5 7 7 7 (D) - - - 20 - (E) - - - - 20 (F) 12 17 20 - - (G) 3 3 3 3 3

(A): polypropylene resin (product name: BI830 by Samsung Total Co., Ltd.)

(B): L-type polylactic acid resin (Nature Works, Ingeo 3251D)

(C): impact stiffener, poly (ethylene-n-butyl acrylate-glycidyl methacrylate) resin (Elvaloy, DuPont)

(D): natural fiber according to Comparative Production Example 1 (natural state jute)

(E): natural fiber according to Comparative Production Example 2 (jute with only alkali treatment)

(F): The natural fiber according to Production Example 1

(G): compatibilizer, maleic anhydride-grafted polypropylene resin (product name: PH-200 manufactured by Lotte Chemical Co., Ltd.)

( Evaluation example )

The compositions prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were injection-molded into the specimens shown in the following measurement methods (ASTM D 638, ASTM D 256, ASTM D 648) And the results are shown in Table 2 below. Tensile properties of specimens were dumbbell shaped specimens. Impact strength specimens used specimens with notched specimens.

1. Tensile properties measurement

Tensile strength was measured using a universal testing machine by making test specimens according to ASTM D 638 (Standard Test Method for Tensile Properties of Plastics).

(Tensile strength [Pa] = maximum load [N] / cross section area of initial sample [m ² ], elongation [%] = elongation to break point / initial length)

2. Impact strength measurement

A test specimen was prepared in accordance with ASTM D 256 (Standard Test Method for Tensile Properties of Plastics), and an impact strength was measured using an Izod impactor.

3. Heat resistance measurement

A test piece was prepared in accordance with ASTM D 648 (Standard Test Method for Deflection Temperature in Plastics Under Flexural Load in the Edgewise Position), and a heat distortion temperature was measured using a universal testing machine.

4. Flexural strength  Measure

In accordance with ASTM D790 (Standard Test Method for FLEXURAL Properties of Plastics), the test specimen is placed on two points separated by a certain distance and the test specimen is loaded at a constant speed under load in the vertical direction until fracture of the specimen occurs Stress and strain were measured.

(Bending strength = 3 P x L / ² b x d ² )

(P: applied force, L: length of support span, b: width of specimen, d: thickness of specimen)

division Mechanical properties The tensile strength
(MPa) Flexural strength
(MPa) Impact strength
(J / m) Heat resistance
(° C) Content of biomass-derived components (%) Example 1 24 39 70 98 25 or more Example 2 26 40 71 115 25 or more Example 3 29 42 70 120 25 or more Comparative Example 1 25 38 55 92 25 or less Comparative Example 2 24 37 54 93 25 or less

As shown in Table 2 above, it was confirmed that a mixture of a polypropylene resin and an L- or D-type poly (lactic acid) resin and an impact modifier poly (ethylene-glycidyl methacrylate) resin, lignin- It was confirmed that the biocomposite materials according to Examples 1 to 4 of the present invention had excellent workability and excellent mechanical properties such as tensile strength, flexural strength, flexural modulus, impact strength, and heat resistance as compared with Comparative Examples 1 and 2 have.

Claims (26)

80 to 93% by weight of a polypropylene resin, and 7 to 20% by weight of a polylactic acid resin; And
And an additive containing 10 to 20 parts by weight of natural fibers per 100 parts by weight of the resin material,
Wherein the natural fiber has O-Si-O bonds connected to the surface of the natural fiber from which lignin and hemicellulose contained therein are removed, and the resin composition for a biocomposite material. The method according to claim 1,
Wherein the O-Si-O bond connected to the surface of the natural fiber exhibits hydrophobicity. The method according to claim 1,
Wherein the lignin is removed by 30 to 50% by weight based on the total amount of the natural fibers. The method according to claim 1,
Wherein the hemicellulose is removed by 5 to 10% by weight based on the total amount of the natural fibers. The method according to claim 1,
Wherein the average length of the natural fibers is 0.01 to 100 mm. The method according to claim 1,
Wherein the natural fibers have an average diameter of 0.001 to 50 탆. delete The method according to claim 1,
Wherein the polylactic acid resin and the natural fiber are contained in an amount of 25% by weight or more based on the total amount of the biocomposite resin composition. The method according to claim 1,
Wherein the additive further comprises at least one of an impact reinforcement, a compatibilizer, a stabilizer, a hydrolysis inhibitor, an antioxidant, a pigment, and a dye. 10. The method of claim 9,
Wherein the impact reinforcing material is a copolymer comprising a butyl (meth) acrylate monomer and a glycidyl (meth) acrylate monomer in a polyethylene skeleton. 10. The method of claim 9,
Wherein the impact reinforcing material is an ethylene copolymer comprising a skeleton represented by the following formulas (1) and (2):
[Chemical Formula 1] < EMI ID =

In Formula 1, m and n are each independently a natural number. 10. The method of claim 9,
Wherein the impact reinforcing material is contained in an amount of 3 to 7 parts by weight based on 100 parts by weight of the resin material. 10. The method of claim 9,
Wherein the impact modifier has a melt index (MI) of 2 to 10 g / 10 min. 10. The method of claim 9,
Wherein the compatibilizer is a maleic anhydride graft polypropylene resin. 15. The method of claim 14,
Wherein the maleic anhydride is grafted to the polypropylene resin in an amount of 0.1 to 5 wt%. 10. The method of claim 9,
Wherein the compatibilizer is contained in an amount of 1 to 5 parts by weight based on 100 parts by weight of the resin material. The method according to claim 1,
Wherein the polylactic acid resin is selected from L-type polylactic acid resin, D-type polylactic acid resin, and a combination thereof. The method according to claim 1,
Wherein the polypropylene resin has a melt index (MI) of 10 to 40 g / 10 min. The method according to claim 1,
Wherein the polylactic acid resin has a melt index (MI) of 5 to 40 g / 10 min. delete delete delete delete delete delete A molded article produced from the resin composition for a biocomposite according to any one of claims 1 to 6, and 8 to 19.

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