Preparation and application of turpentine-based terpene terpolymer

Abstract

This invention relates to a method for preparing and applying a turpentine-based terpolymer. First, turpentine (5.6-7.94 parts), glycidyl methacrylate (2.3-3.78 parts), and vinyl acetate (1.2-2.32 parts) are mixed. Then, 0.07 parts of azobisisobutyronitrile (AIBN) are added as an initiator. The mixture is refluxed at 70-80°C for 4 hours. The resulting solid product is then washed three times with anhydrous ethanol to obtain the turpentine-based terpolymer. Further, the turpentine-based terpolymer is added to starch, glycerol, and lactic acid, and then extruded using an extruder to obtain a thermoplastic starch plastic modified with the turpentine-based terpolymer. This invention marks the first time that a terpolymer of natural turpentine, glycidyl methacrylate, and vinyl acetate has been prepared using a bulk polymerization method. The polymerization process is simple and controllable. Furthermore, the thermoplastic starch plastics prepared using this terpolymer as a modifier exhibit excellent hydrophobicity, with surface water contact angles exceeding 90° (up to a maximum of 104.9°), and also possess good mechanical properties (tensile strength up to 8.9 MPa and elongation at break up to 184.1%). The turpentine-based terpene terpolymer prepared by this method also shows broad application prospects in other plastics, rubbers, fibers, and composite materials.

Description

Technical Field

[0001] This invention belongs to the field of forest product chemistry and processing, specifically relating to a method for preparing a turpentine-based terpolymer and its application in thermoplastic starch plastics. Background Technology

[0002] Bio-based polymer materials are novel polymer materials manufactured using renewable biomass raw materials (such as plants and microorganisms) through biological, chemical, or physical methods. Their core value lies in replacing increasingly depleted fossil resources and reducing carbon footprint, making them a crucial force driving the materials industry towards a green and sustainable direction. Currently, bio-based polymer materials are mainly divided into two categories: natural polymer materials and synthetic bio-based polymer materials. Natural polymer materials are widely used in applications such as the preparation of bioplastics and composite materials, including cellulose, lignin, hemicellulose, starch, proteins, and modified bio-based polymers. Synthetic bio-based polymer materials are mainly derived from various small-molecule biomass, such as vegetable oils, fatty acids, furans, terpenes, rosin acids, and amino acids.

[0003] Starch, with its wide availability, low price, and short recycling cycle, is considered one of the most promising bio-based biodegradable polymer materials. However, the large number of hydrophilic hydroxyl groups in the starch molecule leads to significant drawbacks in starch-based plastics, such as poor surface hydrophobicity and water intolerance. This is especially problematic when starch-based plastics are used in hot beverage or high-humidity environments, where they are prone to absorbing water, swelling, and even dissolving. This deficiency stems from the hydrophilic nature of starch's numerous hydroxyl groups. Furthermore, the mechanical strength and water vapor barrier properties of starch-based plastics are far lower than those of traditional petroleum-based plastics, making them unsuitable for the practical needs of food packaging and other fields.

[0004] Turpentine is a major forest chemical product. my country ranks first in the world in annual turpentine production. Using turpentine as a raw material to produce high-value-added fine chemical products aligns with the sustainable development strategy and has significant economic and research value. The main components of turpentine are a mixture of bicyclic monoterpenes (α-pinene 65-86%, β-pinene 3-36%). Copolymers synthesized using turpentine as monomers are called terpene copolymers. Patent CN121758673A reports a method for preparing terpene copolymers and their applications: turpentine and glycidyl methacrylate (1:1 molar ratio) are mixed, and azobisisobutyronitrile (AIB) is added as an initiator. The mixture is refluxed at 80°C to generate the terpene copolymer. The addition of this copolymer improves the surface water contact angle of thermoplastic starch plastics to 91°–100.7°, but the mechanical properties are poor (tensile strength only 1.689–3.273 MPa), indicating a significant gap from practical applications. Summary of the Invention

[0005] To address the technical problem of insufficient mechanical properties in existing thermoplastic starch plastics, the inventors unexpectedly discovered that a copolymer prepared by ternary copolymerization of turpentine, glycidyl methacrylate, and vinyl acetate, as a modifier, can significantly improve the mechanical properties of thermoplastic starch plastics while maintaining good surface hydrophobic properties. Based on this discovery, the present invention was completed.

[0006] Therefore, the present invention provides a method for preparing a turpentine-based terpolymer.

[0007] Specifically, the turpentine-based terpene terpolymer of the present invention is composed of the following components by weight ratio:

[0008] Turpentine oil 5.6-7.94 parts

[0009] Glycidyl methacrylate 2.3-3.78 parts

[0010] Vinyl acetate 1.2 parts - 2.32 parts

[0011] This terpolymer can be used as a modifier to improve the mechanical and surface hydrophobic properties of thermoplastic starch plastics.

[0012] Specifically, the turpentine-based terpene terpolymer-modified thermoplastic starch plastic of the present invention is composed of the following components by weight ratio:

[0013] 75 parts starch

[0014] 20 parts glycerin

[0015] Lactic acid 5.0 parts

[0016] 1.0 part of turpentine-based terpene copolymer

[0017] The specific method used in this invention is as follows:

[0018] 1) Preparation of turpentine-based terpolymer

[0019] Turpentine oil (5.6-7.94 parts), glycidyl methacrylate (2.3-3.78 parts), and vinyl acetate (1.2-2.32 parts) were mixed, and then 0.07 parts of azobisisobutyronitrile were added as an initiator. The mixture was refluxed at 70-80°C for 4 hours. The solid product was then washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer.

[0020] 2) Preparation of thermoplastic starch plastics modified with turpentine-based terpolymer

[0021] Take 75 parts of starch, add 25 parts of glycerol, 5 parts of lactic acid and 1.0 part of turpentine-based terpolymer, mix evenly, and extrude a sample in a single-screw extruder. The barrel temperature is 105-110℃, the die temperature is 100-105℃, and the rotation speed is 30-40 r / min. Inject into an injection molding machine at temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, and an injection pressure of 70 MPa to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

[0022] The advantages of this invention are:

[0023] 1) This turpentine-based terpene terpolymer polymerization method is a bulk polymerization, and the polymerization process is simple and controllable;

[0024] 2) Turpentine oil and starch are widely available and have low costs, making them promising for market applications;

[0025] 3) The thermoplastic starch plastic prepared by adding this turpentine-based terpene terpolymer exhibits excellent mechanical and surface hydrophobic properties, and its surface...

[0026] The contact angle can reach over 90°. Attached Figure Description

[0027] Figure 1 Preparation mechanism of terpolymer of turpentine oil, glycidyl methacrylate and vinyl acetate

[0028] Figure 2 Infrared spectra of turpentine oil, glycidyl methacrylate, vinyl acetate, and turpentine-based terpolymer

[0029] As attached Figure 2 Turpentine-based terpene copolymer at 1717 cm⁻¹ -1 A strong peak appears at 1251 cm⁻¹, which is attributed to the C=O stretching vibration of glycidyl methacrylate; -1 The peak at 990 cm⁻¹ represents the non-coaxial stretching of the COC of the glycidyl methacrylate epoxy ring; -1 904cm -1 840cm -1 The presence of multiple strong peaks at these locations indicates that a ternary copolymerization reaction has occurred between turpentine oil, glycidyl methacrylate, and vinyl acetate.

[0030] Figure 3 Water contact angle diagrams of the surfaces in each embodiment and comparative example.

[0031] As attached Figure 3In each embodiment, the surface water contact angle reaches more than 90°, showing high surface hydrophobicity. Detailed Implementation

[0032] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0033] In the following examples and comparative examples, the starch plastic film obtained by hot pressing was cut into standard samples of 40×10×0.6mm and tested using an E44.304 electronic universal testing machine from MTS Industrial Systems (China) Co., Ltd., with a tensile rate of 50mm / min.

[0034] Comparative Example 1:

[0035] Mix 75 parts starch, 20 parts glycerol, and 5 parts lactic acid evenly in a container; extrude and granulate in a single-screw or twin-screw extruder, with each temperature zone of the extruder at 110℃ and a rotation speed of 25–35 r / min; then inject the mixture into an injection molding machine, with each temperature zone of the injection molding machine at 145℃, 140℃, 135℃, 130℃, and 130℃, and an injection pressure of 70 MPa, to obtain thermoplastic starch plastic.

[0036] Example 1:

[0037] 1) Preparation of turpentine-based terpolymer

[0038] 6.4 g turpentine oil, 2.5 g glycidyl methacrylate, and 1.2 g vinyl acetate were mixed, and 0.07 g azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80 °C for 1 hour, and then the solid product was washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer.

[0039] 2) Preparation of thermoplastic starch plastics modified with turpentine-based terpolymer

[0040] 75g of starch, 25g of glycerol, and 1.0g of turpentine-based terpolymer were uniformly mixed in a container; the mixture was then extruded and granulated in a single-screw or twin-screw extruder at a temperature of 110℃ in all extruder zones and a rotation speed of 25–35 r / min; the mixture was then injection molded in an injection molding machine at temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, with an injection pressure of 70 MPa, to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

[0041] Example 2:

[0042] 1) Preparation of turpentine-based terpolymer

[0043] 5.6 g of turpentine oil, 2.3 g of glycidyl methacrylate, and 2.1 g of vinyl acetate were mixed, and 0.07 g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80 °C for 2 hours, and then the solid product was washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer.

[0044] 2) Preparation of thermoplastic starch plastics modified with turpentine-based terpolymer

[0045] 75g of starch, 25g of glycerol, and 1.0g of turpentine-based terpolymer were uniformly mixed in a container; the mixture was then extruded and granulated in a single-screw or twin-screw extruder at a temperature of 110℃ in all extruder zones and a rotation speed of 25–35 r / min; the mixture was then injection molded in an injection molding machine at temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, with an injection pressure of 70 MPa, to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

[0046] Example 3:

[0047] 1) Preparation of turpentine-based terpolymer

[0048] 5.7g of turpentine oil, 2.6g of glycidyl methacrylate, and 1.7g of vinyl acetate were mixed, and 0.07g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 4 hours, and then the solid product was washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer.

[0049] 2) Preparation of thermoplastic starch plastics modified with turpentine-based terpolymer

[0050] 75g of starch, 25g of glycerol, and 1.0g of turpentine-based terpolymer were uniformly mixed in a container; the mixture was then extruded and granulated in a single-screw or twin-screw extruder at a temperature of 110℃ in all extruder zones and a rotation speed of 25–35 r / min; the mixture was then injection molded in an injection molding machine at temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, with an injection pressure of 70 MPa, to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

[0051] Example 4:

[0052] 1) Preparation of turpentine-based terpolymer

[0053] 5.9 g of turpentine oil, 2.8 g of glycidyl methacrylate, and 1.4 g of vinyl acetate were mixed, and 0.07 g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80 °C for 4 hours, and then the solid product was washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer.

[0054] 2) Preparation of thermoplastic starch plastics modified with turpentine-based terpolymer

[0055] 75g of starch, 25g of glycerol, and 1.0g of turpentine-based terpolymer were uniformly mixed in a container; the mixture was then extruded and granulated in a single-screw or twin-screw extruder at a temperature of 110℃ in all extruder zones and a rotation speed of 25–35 r / min; the mixture was then injection molded in an injection molding machine at temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, with an injection pressure of 70 MPa, to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

[0056] Example 5:

[0057] 1) Preparation of turpentine-based terpolymer

[0058] 7.74 g turpentine oil, 3.64 g glycidyl methacrylate, and 1.51 g vinyl acetate were mixed, and 0.07 g azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80 °C for 4 hours, and then the solid product was washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer.

[0059] 2) Preparation of thermoplastic starch plastics modified with turpentine-based terpolymer

[0060] 75g of starch, 25g of glycerol, and 1.0g of turpentine-based terpolymer were uniformly mixed in a container; the mixture was then extruded and granulated in a single-screw or twin-screw extruder at a temperature of 110℃ in all extruder zones and a rotation speed of 25–35 r / min; the mixture was then injection molded in an injection molding machine at temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, with an injection pressure of 70 MPa, to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

[0061] Example 6:

[0062] 1) Preparation of turpentine-based terpolymer

[0063] 6.8 g of turpentine oil, 3.6 g of glycidyl methacrylate, and 2.13 g of vinyl acetate were mixed, and 0.07 g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80 °C for 4 hours, and then the solid product was washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer.

[0064] 2) Preparation of thermoplastic starch plastics modified with turpentine-based terpolymer

[0065] 75g of starch, 25g of glycerol, and 1.0g of turpentine-based terpolymer were uniformly mixed in a container; the mixture was then extruded and granulated in a single-screw or twin-screw extruder at a temperature of 110℃ in all extruder zones and a rotation speed of 25–35 r / min; the mixture was then injection molded in an injection molding machine at temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, with an injection pressure of 70 MPa, to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

[0066] Example 7:

[0067] 1) Preparation of turpentine-based terpolymer

[0068] 7.22 g turpentine oil, 2.84 g glycidyl methacrylate, and 2.32 g vinyl acetate were mixed, and 0.07 g azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80 °C for 4 hours, and then the solid product was washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer.

[0069] 2) Preparation of thermoplastic starch plastics modified with turpentine-based terpolymer

[0070] 75g of starch, 25g of glycerol, and 1.0g of turpentine-based terpolymer were uniformly mixed in a container; the mixture was then extruded and granulated in a single-screw or twin-screw extruder at a temperature of 110℃ in all extruder zones and a rotation speed of 25–35 r / min; the mixture was then injection molded in an injection molding machine at temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, with an injection pressure of 70 MPa, to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

[0071] Example 8:

[0072] 1) Preparation of turpentine-based terpolymer

[0073] 7.94 g turpentine oil, 3.78 g glycidyl methacrylate, and 1.29 g vinyl acetate were mixed, and 0.07 g azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 4 hours, and then the solid product was washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer.

[0074] 2) Preparation of thermoplastic starch plastics modified with turpentine-based terpolymer

[0075] 75g of starch, 25g of glycerol, and 1.0g of turpentine-based terpolymer were uniformly mixed in a container; the mixture was then extruded and granulated in a single-screw or twin-screw extruder at a temperature of 110℃ in all extruder zones and a rotation speed of 25–35 r / min; the mixture was then injection molded in an injection molding machine at temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, with an injection pressure of 70 MPa, to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

[0076] Table 1

[0077]

[0078] Table 1 above shows the mechanical property data of the comparative examples and various embodiments. The test data shows that the mechanical properties of the thermoplastic starch plastic modified by the turpentine-based terpolymer of the present invention are significantly improved, and the tensile strength and elongation at break can be improved simultaneously.

Claims

1. A method for preparing a turpentine-based terpene terpolymer and its application, characterized in that: The preparation of the turpentine-based terpene terpolymer and its application in thermoplastic starch plastics are achieved according to the following steps: Turpentine oil (5.6-7.94 parts), glycidyl methacrylate (2.3-3.78 parts), and vinyl acetate (1.2-2.32 parts) were mixed, and then 0.07 parts of azobisisobutyronitrile were added as an initiator. The mixture was refluxed at 70-80°C for 4 hours. The resulting solid product was then washed three times with anhydrous ethanol to obtain a turpentine-based terpolymer. Take 75 parts of starch, add 20 parts of glycerol, 5 parts of lactic acid and 1.0 part of turpentine-based terpolymer, and mix evenly; extrude a sample in a single-screw extruder with a barrel temperature of 105-110℃, a die temperature of 100-105℃, and a rotation speed of 30-40 r / min; inject the sample into an injection molding machine with temperatures of 145℃, 140℃, 135℃, 130℃, and 130℃, and an injection pressure of 70 MPa to obtain turpentine-based terpolymer-modified thermoplastic starch plastic.

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