Method for preparing biodegradable resin composition using composite compatibilizer and biomass-based biodegradable resin composition prepared thereby

Abstract

The present invention relates to a method for preparing a biomass-based biodegradable resin composition using a composite compatibilizer, and a biodegradable resin composition having an improved melt flow index and a biodegradable film having excellent mechanical properties produced thereby.

Description

Technical Field

[0001] The present invention relates to a method for preparing a biomass-based biodegradable resin composition, and more particularly, to a method for preparing a biomass-based biodegradable resin composition using a composite compatibilizer, and a biodegradable resin composition having improved melt fluidity and a biodegradable film having excellent mechanical properties manufactured therefrom. Background Art

[0002] Biodegradable polymers can be classified into petroleum-derived biodegradable polymers and bio-derived biodegradable polymers, and the interest in environmentally friendly and renewable bio-derived polymers is relatively high. Polymers that can be completely biodegradable in the earth environment contain functional groups that can be degraded by microorganisms in their main chain structure. Among these polymers, polyester-based polymers have been the most studied because they have excellent processability and biodegradability that is easy to control. For example, polylactic acid (PLA) is a bio-derived biodegradable polymer synthesized from lactic acid obtained by fermenting corn starch, and the global market size is about 100,000 tons, and its application fields are expanding to general plastics such as food packaging and containers, and electronic product housings. However, due to the lack of moldability, mechanical strength, and heat resistance of PLA resin, film products are prone to breakage. In addition, due to its low temperature resistance, molded products are deformed when the external temperature rises.

[0003] In addition, as the most commonly used petroleum-derived biodegradable polyester-based polymer, poly(butylene adipate-co-terephthalate) (PBAT) is a copolymer resin containing aliphatic and aromatic groups, and has relatively excellent mechanical properties and processability, but has disadvantages such as weak structural strength and high manufacturing cost. In order to solve the above-mentioned disadvantages of polyester resins, that is, to improve their poor physical properties and reduce the relatively high manufacturing cost compared with non-biodegradable polymers, various research methods for manufacturing composite materials by incorporating biomass (an environmentally friendly material) have been proposed.

[0004] To this end, developments have been made to reduce costs and improve biodegradability by mixing biodegradable resins with starch, which is a typical plant biomass. However, the application of starch in biodegradable resins generally has problems of limited starch addition amount and product quality degradation, which are caused by the inherent hydrophilicity of starch and poor processability resulting in a decrease in physical properties.

[0005] To solve the above problems, various attempts have been made to impart thermoplasticity by reacting starch with a plasticizer, etc., and to manufacture composite materials by mixing starch with biodegradable resins, but these attempts have not yet met the standards of the industrial field. Therefore, there is a need to develop environmentally friendly materials that can simultaneously satisfy biodegradability, mechanical properties, and economic efficiency. SUMMARY OF THE INVENTION

[0006] [Technical Problem]

[0007] The present invention aims to provide a method for preparing a biomass-based biodegradable resin composition having excellent melt fluidity.

[0008] The present invention also aims to provide a biodegradable resin composition having improved melt fluidity, which is prepared from a biomass composite containing starch by introducing two or more types of composite compatibilizers.

[0009] The present invention also aims to provide an environmentally friendly biodegradable film having excellent biodegradability and mechanical properties.

[0010] [Technical Solution]

[0011] To solve the above technical challenges, on the one hand, a method for preparing a biomass-based biodegradable resin composition is provided, the method comprising: preparing a biomass composite by reacting starch, a plasticizer, a compatibilizer containing two dicarboxylic acids, and a reaction initiator; and mixing the biomass composite with a biodegradable resin.

[0012] In one embodiment, the compatibilizer may include maleic anhydride and tartaric acid. In one embodiment, based on the total weight of the biomass composite, the content of maleic anhydride may be 0.3 wt% to 3 wt%, and the content of tartaric acid may be 0.1 wt% to 2 wt%. The compatibilizer may further include a styrene-unsaturated dicarboxylic acid copolymer or a styrene-unsaturated dicarboxylic anhydride copolymer in an amount of 0.05 wt% to 2.5 wt%.

[0013] In one embodiment, based on the total weight of the biomass composite, the content of starch may be 70 wt% to 90 wt%, the content of the plasticizer may be 5 wt% to 20 wt%, the content of the two types of composite compatibilizers may be 0.1 wt% to 5 wt%, and the content of the reaction initiator may be 0.1 wt% to 1 wt%.

[0014] In one embodiment, based on the total weight of the biomass composite, the content of starch may be 75 wt% to 90 wt%, the content of the plasticizer may be 5 wt% to 20 wt%, the content of the two types of composite compatibilizers may be 0.1 wt% to 5 wt%, and the content of the reaction initiator may be 0.1 wt% to 1 wt%.

[0015] According to one embodiment, the melt flow index of the biomass composite may be 0.01 g / min to 500 g / min at 200 °C.

[0016] According to one embodiment, 20 wt% to 40 wt% of a biomass composite may be mixed with 60 wt% to 80 wt% of a biodegradable resin to prepare a biomass-based biodegradable resin composition.

[0017] The plasticizer may be, for example, at least one selected from glycerol, ethylene glycol, sorbitol, and pentaerythritol, but is not limited thereto.

[0018] The starch may be, for example, at least one selected from corn starch, waxy corn starch, rice starch, potato starch, tapioca starch, wheat starch, sweet potato starch, and their modified starches, but is not limited thereto.

[0019] The reaction initiator may be, for example, at least one peroxide-based reaction initiator selected from benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, di-tert-butyl hydrogen peroxide, dibenzoyl peroxide, succinic peroxide, dilauroyl peroxide, didecanoyl peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, α-cumyl peroxyneodecanoate, 1,1-dimethyl-3-hydroxybutyl peroxy-2-ethylhexanoate, tert-amyl peroxybenzoate, tert-butyl peroxypivalate, 2,5-dihydroxyperoxy-2,5-dimethylhexane, cumene hydroperoxide, and 1,3-bis(tert-butylperoxyisopropyl)benzene, but is not limited thereto.

[0020] The biodegradable resin may be, for example, at least one selected from polylactic acid, poly(butylene adipate terephthalate), poly(butylene succinate), polycaprolactone, polyglycolic acid, polyhydroxyalkanoates, polyhydroxybutyrate, their copolymers, and their mixtures, but is not limited thereto.

[0021] According to one embodiment, the preparation of the biomass composite may further include extruding the biomass composite into pellets.

[0022] According to one embodiment, the mixing of the biomass composite pellets and the biodegradable resin may further include extruding the resin mixture into pellets.

[0023] On the other hand, a biomass-based biodegradable resin composition prepared by the above method is provided.

[0024] On another aspect, a biodegradable film manufactured using the above biomass-based biodegradable resin composition is provided.

[0025] According to one embodiment, the tensile strength of the biodegradable film may be 27 N / mm 2 to 30 N / mm 2 .

[0026] According to one embodiment, the tear strength of the biodegradable film can be from 96 N / mm to 131 N / mm.

[0027] According to one embodiment, the elongation at break of the biodegradable film can be from 580% to 670%.

[0028] [Beneficial effects]

[0029] In the compatibilization system optimized according to the present invention, the starch-containing biomass composite prepared by using the reactive extrusion technology can have improved melt fluidity compared with conventional thermoplastic starch. Therefore, when the biomass composite with excellent melt fluidity is mixed with the biodegradable resin to manufacture the flexible film, the mechanical properties of the film can be improved. Detailed embodiments

[0030] The present invention will be described in more detail below in conjunction with the embodiments. However, the following embodiments are provided only as examples to help understand the present invention and are not intended to limit the scope of the present invention. The present invention can be variously modified and can be implemented in many different forms, and it should be understood to include all modifications, equivalents or alternatives falling within the spirit and technical scope of the present invention.

[0031] In addition, unless otherwise defined, all terms used herein, including technical terms or scientific terms, have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. Unless clearly defined in the present application, terms, such as those defined in common dictionaries, should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense.

[0032] Specifically, according to one aspect of the present invention, a method for preparing a biomass-based biodegradable resin composition includes: preparing a biomass composite by reacting starch, a plasticizer, a composite compatibilizer containing two dicarboxylic acids, and a reaction initiator; and mixing the biomass composite with a biodegradable resin.

[0033] According to one embodiment, the composite compatibilizer can include maleic anhydride and tartaric acid. In one embodiment, based on the total weight of the biomass composite, the content of maleic anhydride is 0.3 wt% to 3 wt%, and the content of tartaric acid is 0.1 wt% to 2 wt%. In addition, the compatibilizer can further include 0.05 wt% to 2.5 wt% of a styrene-unsaturated dicarboxylic acid copolymer or a styrene-unsaturated dicarboxylic anhydride copolymer.

[0034] When the content of maleic anhydride is less than 0.1 wt%, the compatibilization effect is not significant, while when the content of maleic anhydride exceeds 3 wt%, the physical properties of the biomass composite, such as the melt flow index and color, change significantly.

[0035] When the tartaric acid content is less than 0.1 wt%, the compatibilization effect is not significant. When the tartaric acid content exceeds 2 wt%, the physical properties of the biomass composite, such as the melt flow index and color, change significantly. With the increase of the tartaric acid content, the processability of the biomass composite decreases, and the surface viscosity increases, resulting in a decrease in the mechanical properties of the film.

[0036] In addition to maleic anhydride and tartaric acid, the composite compatibilizer may also include a styrene-unsaturated dicarboxylic acid copolymer or a styrene-unsaturated dicarboxylic anhydride copolymer. For example, at least one selected from styrene-maleic acid copolymer, styrene-fumaric acid copolymer, styrene-acetylene dicarboxylic acid copolymer, styrene-glutaconic acid copolymer, styrene-2-decenedicarboxylic acid copolymer, styrene- traumatic acid copolymer, styrene-muconic acid copolymer, styrene-glutaric acid copolymer, styrene-citraconic acid copolymer, styrene-mesaconic acid copolymer, styrene-itaconic acid copolymer, styrene-maleic anhydride copolymer, styrene-fumaric anhydride copolymer, styrene-acetylene dicarboxylic anhydride copolymer, styrene-glutaconic anhydride copolymer, styrene-2-decenedicarboxylic anhydride copolymer, styrene- traumatic acid anhydride copolymer, styrene-muconic acid anhydride copolymer, styrene-glutaric anhydride copolymer, styrene-citraconic anhydride copolymer, styrene-mesaconic anhydride copolymer and styrene-itaconic anhydride copolymer can be used.

[0037] In one embodiment, based on the total weight of the biomass composite, the starch content can be 70 wt% to 90 wt%, the plasticizer content can be 5 wt% to 20 wt%, the content of two types of composite compatibilizers can be 0.1 wt% to 5 wt%, and the content of the reaction initiator can be 0.1 wt% to 1 wt%.

[0038] In another embodiment, based on the total weight of the biomass composite, the starch content can be 75 wt% to 90 wt%, the plasticizer content can be 5 wt% to 20 wt%, the content of two types of composite compatibilizers can be 0.1 wt% to 5 wt%, and the content of the reaction initiator can be 0.1 wt% to 1 wt%.

[0039] When using less than 70 wt% of starch, raw materials other than starch may be overused, which increases costs and makes it uneconomical. When using more than 90 wt% of starch, some starch may remain unplasticized, which reduces the physical properties in the manufacture of thermoplastic starch and biodegradable composite resins.

[0040] When using less than 5 wt% of plasticizer, the starch may not be sufficiently plasticized. When using more than 20 wt% of plasticizer, the plasticizer may be eluted due to overuse during the application of the film.

[0041] When the compatibilizer is used in a small amount of less than 0.1 wt%, the effect is not significant. While when the compatibilizer is used in an amount greater than 5 wt%, due to the excessive use, physical properties such as color and melt flow index change significantly.

[0042] When a reaction initiator of less than 0.1 wt% is used, the reactivity between raw materials may be insufficient. While when a reaction initiator of more than 1 wt% is used, unreacted initiator may remain, which will reduce the numerical limit of the biomass composite.

[0043] According to one embodiment, the melt flow index of the biomass composite may be from 0.01 g / min to 500 g / min at 200 °C.

[0044] When the melt flow index is less than 0.01 g / min at 200 °C, low fluidity is shown, and the processability of the biomass composite decreases significantly, making it impossible to manufacture. When the melt flow index exceeds 500 g / min at 200 °C, it is not suitable for extrusion molding and will reduce the mechanical properties of the film.

[0045] After preparing a biomass composite containing starch using two types of composite compatibilizers, the biomass composite is mixed with a biodegradable resin to prepare a biodegradable resin composition. In this case, a biomass-based biodegradable resin composition can be prepared by mixing 20 wt% to 40 wt% of the biomass composite with 60 wt% to 80 wt% of the biodegradable resin. When a biomass composite containing starch is prepared using two types of composite compatibilizers according to the present invention, the melt fluidity is improved, so the starch content in the resin composition can be increased, thus meeting the characteristics of environmentally friendly products.

[0046] By applying a compatibilization system capable of controlling melt fluidity, a higher level of melt fluidity than conventional thermoplastic starch and a similar level of melt fluidity to biodegradable resin (molecular weight: starch > biodegradable resin) can be ensured. High melt fluidity has a great impact on the mechanical strength of the film.

[0047] The plasticizer that can be used in the embodiment can be, for example, at least one selected from glycerol, ethylene glycol, sorbitol, and pentaerythritol, but is not limited thereto.

[0048] The starch that can be used in the embodiment can be, for example, at least one selected from corn starch, waxy corn starch, rice starch, potato starch, cassava starch, wheat starch, sweet potato starch, and their modified starches, but is not limited thereto.

[0049] The reaction initiators that can be used in the embodiments can be, for example, at least one peroxide-based reaction initiator selected from benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, di-tert-butyl hydroperoxide, dibenzoyl peroxide, succinic peroxide, dilauroyl peroxide, didecanoyl peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, cumyl α-neodecanoate peroxide, 1,1-dimethyl-3-hydroxybutyl peroxy-2-ethylhexanoate, tert-amyl benzoate peroxide, tert-butyl pivalate peroxide, 2,5-dihydroxyperoxy-2,5-dimethylhexane, cumene hydroperoxide, and 1,3-bis(tert-butylperoxyisopropyl)benzene, but not limited thereto.

[0050] The biodegradable resins that can be used can be, for example, at least one of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), polyglycolic acid (PGA), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), their copolymers, and their mixtures, but not limited thereto.

[0051] According to another embodiment of the present invention, the preparation of the biomass composite may further include extruding the biomass composite into pellets. In addition, the mixing of the biomass composite pellets and the biodegradable resin may further include extruding the resin mixture into pellets and then putting the obtained pellets into a film-forming machine to manufacture a biodegradable film.

[0052] According to another aspect of the present invention, there are provided a biomass-based biodegradable resin composition prepared by the above method and a biodegradable film manufactured using the biodegradable resin composition.

[0053] The present invention will be described in more detail below with reference to Examples and Comparative Examples.

[0054] [Example 1-1]

[0055] 1) Preparation of biomass composite

[0056] 85 parts by weight of corn starch was mixed with 15 parts by weight of glycerol and put into a heating mixer. Subsequently, maleic anhydride was added in an amount of 0.5 wt% relative to the weight of the mixture. The temperature of the heating mixer was raised to 50°C to 60°C, and then mixed for 4 hours.

[0057] Polylactic acid (PLA) was added to the mixture in an amount of 6 wt% relative to the weight of the mixture. The uniformly mixed composition was put into a twin-screw extruder. The temperature of the extruder barrel was 180°C to 185°C, the main screw speed was 300 rpm, and the raw material feeding speed was 20 rpm. The extrudate was granulated to prepare a biomass composite.

[0058] 2) Preparation of Biodegradable Resin Composition

[0059] Mix 30 parts by weight of the prepared biomass composite with 70 parts by weight of poly(butylene adipate-co-terephthalate) (PBAT). Feed the uniformly mixed composition into a twin-screw extruder. The temperature of the extruder barrel is 175°C to 180°C, the main screw speed is 415 rpm to 420 rpm, and the raw material feeding speed is 110 rpm to 120 rpm. Install a water channel to cool the extrudate ejected from the extruder die with water and granulate it.

[0060] Dry the pellets at 60°C for 24 hours or longer to prepare the biomass-based biodegradable resin composition.

[0061] 3) Manufacture of Biodegradable Film

[0062] Feed the biodegradable resin composition into a film-forming machine to manufacture a biodegradable film. The temperature of the film-forming machine is 150°C to 160°C, and the raw material feeding speed is 900 rpm to 1100 rpm.

[0063] [Example 1-2]

[0064] 1) Preparation of Biomass Composite

[0065] Mix 85 parts by weight of corn starch with 15 parts by weight of glycerol and feed it into a heating mixer. Subsequently, add benzaldehyde in an amount of 0.5 wt% based on the weight of the mixture. Raise the temperature of the heating mixer to 50°C to 60°C and then mix for 4 hours.

[0066] Add PLA to the mixture in an amount of 6 wt% based on the weight of the mixture. Feed the uniformly mixed composition into a twin-screw extruder. The temperature of the extruder barrel is 180°C to 185°C, the main screw speed is 300 rpm, and the raw material feeding speed is 20 rpm. Granulate the extrudate to prepare the biomass composite.

[0067] 2) Preparation of Biodegradable Resin Composition and 3) Manufacture of Biodegradable Film are carried out in the same manner as in Example 1.

[0068] [Example 1-3]

[0069] 1) Preparation of Biomass Composite

[0070] Mix 85 parts by weight of corn starch with 15 parts by weight of glycerol and feed it into a heating mixer. Subsequently, add tartaric acid in an amount of 0.5 wt% based on the weight of the mixture. Raise the temperature of the heating mixer to 50°C to 60°C and then mix for 4 hours.

[0071] The PLA was added to the mixture in an amount of 6 wt% relative to the weight of the mixture. The uniformly mixed composition was fed into a twin-screw extruder. The temperature of the extruder barrel was 180 °C to 185 °C, the main screw speed was 300 rpm, and the raw material feeding speed was 20 rpm. The extrudate was granulated to prepare the biomass composite.

[0072] 2) Preparation of the biodegradable resin composition and 3) Manufacture of the biodegradable film were carried out in the same manner as in Example 1.

[0073] [Example 1-4]

[0074] 1) Preparation of the biomass composite

[0075] 85 parts by weight of corn starch was mixed with 15 parts by weight of glycerol and fed into a heating mixer. Subsequently, maleic anhydride and tartaric acid were added in amounts of 0.5 wt% relative to the weight of the mixture, respectively. The temperature of the heating mixer was raised to 50 °C to 60 °C and then mixed for 4 hours.

[0076] The PLA was added to the mixture in an amount of 6 wt% relative to the weight of the mixture. The uniformly mixed composition was fed into a twin-screw extruder. The temperature of the extruder barrel was 180 °C to 185 °C, the main screw speed was 300 rpm, and the raw material feeding speed was 20 rpm. The extrudate was granulated to prepare the biomass composite.

[0077] 2) Preparation of the biodegradable resin composition and 3) Manufacture of the biodegradable film were carried out in the same manner as in Example 1.

[0078] [Example 1-5]

[0079] 1) Preparation of the biomass composite

[0080] 85 parts by weight of corn starch was mixed with 15 parts by weight of glycerol and fed into a heating mixer. Subsequently, maleic anhydride and tartaric acid were added in amounts of 0.5 wt% and 0.8 wt% relative to the weight of the mixture, respectively. The temperature of the heating mixer was raised to 50 °C to 60 °C and then mixed for 4 hours.

[0081] The PLA was added to the mixture in an amount of 6 wt% relative to the weight of the mixture. The uniformly mixed composition was fed into a twin-screw extruder. The temperature of the extruder barrel was 180 °C to 185 °C, the main screw speed was 300 rpm, and the raw material feeding speed was 20 rpm. The extrudate was granulated to prepare the biomass composite.

[0082] 2) Preparation of the biodegradable resin composition and 3) Manufacture of the biodegradable film were carried out in the same manner as in Example 1.

[0083] [Comparative Example 1]

[0084] 1) Preparation of biomass composite

[0085] Mix 85 parts by weight of corn starch with 15 parts by weight of glycerol and put them into a heating mixer. Subsequently, add maleic anhydride and benzaldehyde in amounts of 0.5 wt% and 0.1 wt% respectively relative to the weight of the mixture. Raise the temperature of the heating mixer to 50°C to 60°C and then mix for 4 hours.

[0086] Add PLA to the mixture in an amount of 6 wt% relative to the weight of the mixture. Put the uniformly mixed composition into a twin-screw extruder. The temperature of the extruder barrel is 180°C to 185°C, the main screw speed is 300 rpm, and the raw material feeding speed is 20 rpm. Granulate the extrudate to prepare the biomass composite.

[0087] 2) Preparation of biodegradable resin composition

[0088] Mix 30 parts by weight of the prepared thermoplastic starch with 70 parts by weight of PBAT. Put the uniformly mixed composition into a twin-screw extruder. The temperature of the extruder barrel is 175°C to 180°C, the main screw speed is 415 rpm to 420 rpm, and the raw material feeding speed is 110 rpm to 120 rpm. Cool the extrudate ejected from the extruder die with water and granulate it by installing a water channel.

[0089] Dry the pellets at 60°C for 24 hours or longer to prepare the biomass-based biodegradable resin composition.

[0090] 3) Manufacture of biodegradable film

[0091] Put the biodegradable resin composition into a film-forming machine to manufacture a biodegradable film. The temperature of the film-forming machine is 150°C to 160°C, and the raw material feeding speed is 900 rpm to 1100 rpm.

[0092] [Comparative Example 2]

[0093] 1) Preparation of biomass composite

[0094] Mix 85 parts by weight of corn starch with 15 parts by weight of glycerol and put them into a heating mixer. Subsequently, add maleic anhydride and benzaldehyde in amounts of 0.5 wt% and 0.1 wt% respectively relative to the weight of the mixture. Raise the temperature of the heating mixer to 50°C to 60°C and then mix for 4 hours.

[0095] PBAT was added to the mixture in an amount of 6 wt% relative to the weight of the mixture. The uniformly mixed composition was fed into a twin-screw extruder. The temperature of the extruder barrel was 180 °C to 185 °C, the main screw speed was 300 rpm, and the raw material feeding speed was 20 rpm. The extrudate was granulated to prepare the biomass composite.

[0096] 2) Preparation of the biodegradable resin composition and 3) Manufacture of the biodegradable film were carried out in the same manner as in Comparative Example 1.

[0097] [Example 2-1]

[0098] 1) Preparation of the biomass composite

[0099] 85 parts by weight of corn starch was mixed with 15 parts by weight of glycerol and fed into a heating mixer. Subsequently, maleic anhydride and tartaric acid were added in amounts of 0.3 wt% and 0.2 wt% relative to the weight of the mixture, respectively. The temperature of the heating mixer was raised to 50 °C to 60 °C and then mixed for 4 hours.

[0100] PBAT was added to the mixture in an amount of 6 wt% relative to the weight of the mixture. The uniformly mixed composition was fed into a twin-screw extruder. The temperature of the extruder barrel was 180 °C to 185 °C, the main screw speed was 300 rpm, and the raw material feeding speed was 20 rpm. The extrudate was granulated to prepare the biomass composite.

[0101] 2) Preparation of the biodegradable resin composition and 3) Manufacture of the biodegradable film were carried out in the same manner as in Example 1.

[0102] [Example 2-2]

[0103] 1) Preparation of the biomass composite

[0104] 85 parts by weight of corn starch was mixed with 15 parts by weight of glycerol and fed into a heating mixer. Subsequently, maleic anhydride and tartaric acid were added in amounts of 0.2 wt% and 0.3 wt% relative to the weight of the mixture, respectively. The temperature of the heating mixer was raised to 50 °C to 60 °C and then mixed for 4 hours.

[0105] PBAT was added to the mixture in an amount of 6 wt% relative to the weight of the mixture. The uniformly mixed composition was fed into a twin-screw extruder. The temperature of the extruder barrel was 180 °C to 185 °C, the main screw speed was 300 rpm, and the raw material feeding speed was 20 rpm. The extrudate was granulated to prepare the biomass composite.

[0106] 2) Preparation of the biodegradable resin composition and 3) Manufacture of the biodegradable film were carried out in the same manner as in Example 1.

[0107] [Example 2-3]

[0108] 1) Preparation of biomass composite

[0109] Mix 85 parts by weight of corn starch with 15 parts by weight of glycerol and put them into a heating mixer. Subsequently, add maleic anhydride and tartaric acid in amounts of 0.4 wt% and 0.2 wt% relative to the weight of the mixture, respectively. Raise the temperature of the heating mixer to 50°C to 60°C, and then mix for 4 hours.

[0110] Add PBAT to the mixture in an amount of 6 wt% relative to the weight of the mixture. Put the uniformly mixed composition into a twin-screw extruder. The temperature of the extruder barrel is 180°C to 185°C, the main screw speed is 300 rpm, and the raw material feeding speed is 20 rpm. Granulate the extrudate to prepare the biomass composite.

[0111] 2) Preparation of biodegradable resin composition and 3) Manufacture of biodegradable film are carried out in the same manner as in Example 1.

[0112] [Example 2-4]

[0113] 1) Preparation of biomass composite

[0114] Mix 85 parts by weight of corn starch with 15 parts by weight of glycerol and put them into a heating mixer. Subsequently, add maleic anhydride and tartaric acid in an amount of 0.3 wt% relative to the weight of the mixture. Raise the temperature of the heating mixer to 50°C to 60°C, and then mix for 4 hours.

[0115] Add PBAT to the mixture in an amount of 6 wt% relative to the weight of the mixture. Put the uniformly mixed composition into a twin-screw extruder. The temperature of the extruder barrel is 180°C to 185°C, the main screw speed is 300 rpm, and the raw material feeding speed is 20 rpm. Granulate the extrudate to prepare the biomass composite.

[0116] 2) Preparation of biodegradable resin composition and 3) Manufacture of biodegradable film are carried out in the same manner as in Example 1.

[0117] [Example 2-5]

[0118] 1) Preparation of biomass composite

[0119] Mix 85 parts by weight of corn starch with 15 parts by weight of glycerol and put them into a heating mixer. Subsequently, add maleic anhydride and tartaric acid in amounts of 0.2 wt% and 0.4 wt% relative to the weight of the mixture, respectively. Raise the temperature of the heating mixer to 50°C to 60°C, and then mix for 4 hours.

[0120] PBAT was added to the mixture in an amount of 6 wt% relative to the weight of the mixture. The uniformly mixed composition was fed into a twin-screw extruder. The temperature of the extruder barrel was 180 °C to 185 °C, the main screw speed was 300 rpm, and the raw material feeding speed was 20 rpm. The extrudate was granulated to prepare a biomass composite.

[0121] 2) Preparation of the biodegradable resin composition and 3) Manufacture of the biodegradable film were carried out in the same manner as in Example 1.

[0122] [Example 2-6]

[0123] 1) Preparation of the biomass composite

[0124] 85 parts by weight of corn starch was mixed with 15 parts by weight of glycerol and fed into a heating mixer. Subsequently, maleic anhydride and tartaric acid were added in amounts of 0.3 wt% and 0.4 wt% relative to the weight of the mixture, respectively. The temperature of the heating mixer was raised to 50 °C to 60 °C, and then mixed for 4 hours.

[0125] PBAT was added to the mixture in an amount of 6 wt% relative to the weight of the mixture. The uniformly mixed composition was fed into a twin-screw extruder. The temperature of the extruder barrel was 180 °C to 185 °C, the main screw speed was 300 rpm, and the raw material feeding speed was 20 rpm. The extrudate was granulated to prepare a biomass composite.

[0126] 2) Preparation of the biodegradable resin composition and 3) Manufacture of the biodegradable film were carried out in the same manner as in Example 1.

[0127] [Evaluation Example]

[0128] The compositions of the biomass-based biodegradable resin compositions prepared in the examples and comparative examples and the mechanical properties of the films manufactured using the resin compositions are shown in Table 1 below.

[0129] Various mechanical properties of the biodegradable film were measured as follows. The biodegradable film was cut into 10-mm-wide pieces according to the KSS M1008 standard to prepare specimens, and the film thickness was recorded using a thickness gauge. The tensile strength, elongation at break, and tear strength of the prepared specimens were measured using an Instron tensile testing machine. The conditions of the tensile test included a grip distance of 60 mm and a test speed of 500 mm / min.

[0130] [Table 1]

[0131]

[0132]

[0133] -MA: Maleic anhydride, BA: Benzaldehyde, TA: Tartaric acid

[0134] [Table 2]

[0135]

[0136] -MA: Maleic anhydride, BA: Benzaldehyde, TA: Tartaric acid

[0137] As shown in the above table, it can be confirmed that the mechanical properties such as tensile strength and tear strength of the biodegradable film manufactured using the composite compatibilizer of maleic anhydride and tartaric acid according to Examples 2-1 to 2-4 are significantly improved, and the water immersion elution results are also improved.

Claims

1. A method for preparing a biomass-based biodegradable resin composition, comprising: Preparing a biomass composite by reacting starch, a plasticizer, a compatibilizer comprising two types of dicarboxylic acids, and a reaction initiator; And Mixing the biomass composite with a biodegradable resin.

2. The method according to claim 1, wherein The compatibilizer comprises maleic anhydride and tartaric acid.

3. The method according to claim 2, wherein, Based on the total weight of the biomass composite, The content of maleic anhydride is 0.3 wt% to 3 wt%, and The content of tartaric acid is 0.1 wt% to 2 wt%.

4. The method according to claim 1, wherein Based on the total weight of the biomass composite, The content of the starch is 75 wt% to 90 wt%, The content of the plasticizer is 5 wt% to 20 wt%, The content of the two types of composite compatibilizer is 0.1 wt% to 5 wt%, and The content of the reaction initiator is 0.01 wt% to 1 wt%.

5. The method according to claim 1, wherein The melt flow index of the biomass composite is 0.01 g / min to 500 g / min at 200 °C.

6. The method according to claim 1, wherein 20 wt% to 40 wt% of the biomass composite is mixed with 60 wt% to 80 wt% of the biodegradable resin.

7. The method according to claim 1, wherein The plasticizer is one or more selected from glycerol, ethylene glycol, sorbitol, and pentaerythritol.

8. The method according to claim 1, wherein, The starch is one or more selected from corn starch, waxy corn starch, rice starch, potato starch, cassava starch, wheat starch, sweet potato starch, and their modified starches.

9. The method according to claim 1, wherein The reaction initiator is one or more peroxide-based reaction initiators selected from benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cumene hydroperoxide, di-tert-butyl hydrogen peroxide, dibenzoyl peroxide, succinic peroxide, dilauroyl peroxide, didecanoyl peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, α-cumyl peroxyneodecanoate, 1,1-dimethyl-3-hydroxybutyl peroxy-2-ethylhexanoate, tert-amyl peroxybenzoate, tert-butyl peroxyneopentanoate, 2,5-dihydroxyperoxy-2,5-dimethylhexane, cumene hydroperoxide, and 1,3-bis(tert-butylperoxyisopropyl)benzene.

10. The method according to claim 1, wherein The biodegradable resin is one or more selected from polylactic acid, polycaprolactone, poly(butylene adipate terephthalate), poly(butylene succinate), polyglycolic acid, polyhydroxyalkanoates, polyhydroxybutyrate, their copolymers, and their mixtures.

11. The method according to claim 1, wherein, The preparation of the biomass composite further comprises extruding the biomass composite into pellets.

12. The method according to claim 1, wherein The mixing of the biomass composite pellets with the biodegradable resin further comprises extruding the resin mixture into pellets.

13. A biomass-based biodegradable resin composition prepared by the method according to claim 1.

14. A biodegradable film made using the biomass-based biodegradable resin composition according to claim 13.

15. The biodegradable film according to claim 14, wherein, The tensile strength of the membrane is 27 N / mm 2 to 30 N / mm 2 .

16. The biodegradable film according to claim 14, wherein, The tear strength of the film is 96 N / mm to 131 N / mm.

17. The biodegradable film according to claim 14, wherein, The elongation at break of the film is 580% to 670%.

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