Preparation and application of terpene copolymer

Abstract

The invention relates to a preparation method and application of a terpene copolymer, which comprises the following steps: mixing turpentine and glycidyl methacrylate in a molar ratio of 1: 1, adding azodiisobutyronitrile (1.5 wt%) as an initiator, carrying out reflux reaction at 80 DEG C for 14 hours, and drying the obtained solid product at 70 DEG C for 2 hours to obtain the terpene copolymer; and further adding the terpene copolymer into a certain amount of starch and glycerol, and extruding by using an extruder to obtain the terpene copolymer modified thermoplastic starch plastic. The copolymer of natural turpentine and glycidyl methacrylate is prepared based on a bulk polymerization method for the first time, and the polymerization process is simple and controllable; meanwhile, the thermoplastic starch plastic prepared after the terpene copolymer is added is excellent in hydrophobicity, the surface water contact angle can reach 90 degrees or above, the mechanical property is obviously improved, and especially on the premise that the tensile strength is improved, the fracture toughness can be effectively improved at the same time. The terpene copolymer prepared by the method also has wide application prospects in the fields of other plastics, rubber, fibers and composite materials.

Description

Technical Field

[0001] This invention belongs to the field of forest chemical products, specifically relating to a method for preparing a terpene copolymer and its application in thermoplastic starch plastics. Background Technology

[0002] Bio-based polymer materials are novel polymer materials manufactured using renewable biomass raw materials through biological, chemical, and physical methods, and are an important component of bio-based materials. The main function of bio-based polymer materials is to replace non-renewable materials such as steel, cement, and petroleum-based plastics to the greatest extent possible, possessing characteristics such as being green and environmentally friendly, using renewable raw materials, and being biodegradable. The global bio-based polymer materials industry is currently in a transitional stage from laboratory research to industrial production and large-scale application. Biomass terpene copolymer materials synthesized using abundant natural agricultural and forestry biomass and its residues have advantages such as renewable raw materials, biodegradability, and environmental compatibility.

[0003] Turpentine oil is an important source of forest chemical products. my country ranks first in the world in annual turpentine oil production. Using turpentine oil as a raw material to produce high-value-added fine chemical products is in line with the strategy of sustainable development and has significant economic value and research significance. The main components of turpentine oil are a mixture of bicyclic monoterpenes (α-pinene 65-86%, β-pinene 3-36%), and the copolymers synthesized from it are called terpene copolymers.

[0004] Patent CN119080983B discloses a molecular weight controllable terpene resin and its preparation method: β-pinene is mixed with ethylene glycol to obtain a mixture; toluene and catalyst are mixed until homogeneous at -5 to -5℃; the mixture is added dropwise and kept at 5 to 10℃ for 1 to 3 hours; the catalyst is removed; toluene is desoluble and the product is discharged, with a toluene to β-pinene mass ratio of (1-1.15):1, the catalyst dosage being 3.5-5% of the β-pinene mass, and the ethylene glycol dosage being 0.04-0.07% of the β-pinene mass. This patented preparation process requires control of temperature, proportions, and operating steps, making the process relatively complex; the water content of β-pinene needs to be controlled below 250 ppm, requiring high purity of the raw materials; the reaction needs to be carried out at specific temperatures and vacuum levels, placing high demands on the equipment. Patent CN116874716B discloses a method for preparing a terpene-type epoxy polyurethane prepolymer: α-terpinene, maleic anhydride, a catalyst, and a polar solvent are mixed and reacted to generate a terpene maleic anhydride compound; epichlorohydrin and the terpene maleic anhydride compound are reacted in a polar solvent with a catalyst to generate a terpene-type epoxy resin; isocyanate is added to the terpene-type epoxy resin to obtain the terpene-type epoxy polyurethane prepolymer. This patent involves complex and cumbersome experiments to generate the terpene-type epoxy resin, and the process flow is not simple enough.

[0005] Against the backdrop of dwindling global oil resources and soaring prices, the development and application of biomass resources such as starch have attracted widespread international attention. Starch-based bioplastics, due to their degradability and renewability, are considered an effective way to solve plastic pollution and have become an environmentally friendly alternative to petroleum-based plastics. Starch has advantages such as wide availability, low price, and short recycling cycle, making it considered one of the most promising biodegradable materials. However, the large number of hydrophilic hydroxyl groups in the starch molecule structure leads to core problems such as poor hydrophobicity and poor water resistance in starch-based plastics, severely limiting their application value in humid environments such as food packaging and catering utensils. When starch-based plastics are used in hot beverage or high-humidity environments, the material is prone to water absorption, swelling, and even dissolution. This defect stems from the hydrophilic nature of starch's polyhydroxyl groups; the crystalline regions formed by hydrogen bonding between its molecular chains are easily destroyed in water. More importantly, the mechanical properties and water resistance of starch-based plastics are far lower than those of traditional petroleum-based plastics, making them difficult to meet the practical needs of food packaging and other fields. Summary of the Invention

[0006] To address the technical problems of complex terpene polymer processing and insufficient mechanical and water resistance properties of thermoplastic starch plastics in existing technologies, the inventors unexpectedly discovered that using a copolymer generated from the copolymerization of natural turpentine and glycidyl methacrylate as an additive can effectively improve the surface hydrophobicity of thermoplastic starch plastics, while simultaneously increasing their elongation at break and tensile strength. Based on these findings, this invention was thus completed.

[0007] Therefore, the present invention provides a method for preparing terpene copolymers.

[0008] The present invention will also provide applications of terpene copolymers as reinforcements and tougheners for thermoplastic starch plastics, as well as for their high hydrophobicity.

[0009] Specifically, the terpene copolymer-reinforced and toughened thermoplastic starch of the present invention is composed of the following components by weight ratio:

[0010] 75 parts starch

[0011] 25 parts glycerin

[0012] Terpene copolymer 1.0 part to 5.0 parts

[0013] The specific method used in this invention is as follows:

[0014] 1) Preparation of terpene copolymers

[0015] Turpentine oil and glycidyl methacrylate were mixed in a molar ratio of 1:1, and then 0.3 parts of azobisisobutyronitrile were added as an initiator. The mixture was refluxed at 70-80°C for 1-4 hours, and then the solid product was dried at 70°C for 2 hours to obtain a terpene copolymer.

[0016] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0017] Take another 75 parts of starch, add 25 parts of glycerol and 1.0 to 5.0 parts of terpene copolymer, mix evenly, and extrude a sample in a single screw extruder. The barrel temperature is 115 to 125°C, the die temperature is 105 to 115°C, and the rotation speed is 30 to 40 r / min. Hot press at 110 to 120°C to obtain a reinforced, toughened, and highly hydrophobic thermoplastic starch plastic.

[0018] The specific method used in this invention is as follows:

[0019] The advantages of this invention are:

[0020] 1) This terpene copolymer polymerization method is bulk polymerization, the polymerization process is simple, and the reaction conditions are easy to achieve;

[0021] 2) Turpentine oil and starch are widely available and have low costs, making them promising for market applications;

[0022] 3) The thermoplastic starch plastics prepared after adding this terpene copolymer have excellent hydrophobicity, all reaching above 90°. Attached Figure Description

[0023] Figure 1 Schematic diagram of the preparation principle of bulk polymerization of turpentine oil and glycidyl methacrylate

[0024] Figure 2 Infrared spectra of turpentine oil, glycidyl methacrylate and terpene copolymer

[0025] As attached Figure 2 1717cm of terpene copolymer -1 A strong peak appears at this point, which may be due to the C=O stretching vibration of glycidyl methacrylate; terpene copolymer at 1251 cm⁻¹. -1 The peak here may be due to the non-symmetrical stretching of the COC of the epoxy ring in glycidyl methacrylate; terpene copolymer 1635 cm⁻¹ -1 A weak peak appears at [location], which may belong to the double bond within the ring of turpentine (α-pinene); terpene copolymer [value] 990 cm⁻¹ -1 904cm -1 840cm -1 The presence of multiple strong peaks at these locations likely corresponds to characteristic regions of the terpene ring. These absorption peaks suggest a high probability of copolymerization between turpentine oil and glycidyl methacrylate.

[0026] Figure 3 Water contact angle diagrams of the surfaces in each embodiment and comparative example.

[0027] As attached Figure 3 In each embodiment, the surface water contact angle reaches more than 90°, demonstrating high surface hydrophobicity. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] Comparative Example 1:

[0031] Mix 75 parts starch and 25 parts glycerol evenly in a container; extrude and granulate in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot press in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0032] Example 1:

[0033] 1) Preparation of terpene copolymers

[0034] 10.2g of turpentine oil and 10.6g of glycidyl methacrylate were mixed, and 0.3g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 1 hour, and then the solid product was dried at 70°C for 2 hours to obtain a terpene polymer.

[0035] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0036] 75g of starch, 25g of glycerol and 1.5g of terpene copolymer were uniformly mixed in a container; granulation was carried out in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot pressing was carried out in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0037] Example 2:

[0038] 1) Preparation of terpene copolymers

[0039] 10.2g of turpentine oil and 10.6g of glycidyl methacrylate were mixed, and 0.3g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 2 hours, and then the solid product was dried at 70°C for 2 hours to obtain the terpene polymer.

[0040] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0041] 75g of starch, 25g of glycerol and 1.5g of terpene copolymer were uniformly mixed in a container; granulation was carried out in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot pressing was carried out in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0042] Example 3:

[0043] 1) Preparation of terpene copolymers

[0044] 10.2g of turpentine oil and 10.6g of glycidyl methacrylate were mixed, and 0.3g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 3 hours, and then the solid product was dried at 70°C for 2 hours to obtain the terpene polymer.

[0045] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0046] 75g of starch, 25g of glycerol and 1.5g of terpene copolymer were uniformly mixed in a container; granulation was carried out in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot pressing was carried out in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0047] Example 4:

[0048] 1) Preparation of terpene copolymers

[0049] 10.2g of turpentine oil and 10.6g of glycidyl methacrylate were mixed, and 0.3g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 4 hours, and then the solid product was dried at 70°C for 2 hours to obtain the terpene polymer.

[0050] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0051] 75g of starch, 25g of glycerol and 1.5g of terpene copolymer were uniformly mixed in a container; granulation was carried out in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot pressing was carried out in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0052] Example 5:

[0053] 1) Preparation of terpene copolymers

[0054] 10.2g of turpentine oil and 10.6g of glycidyl methacrylate were mixed, and 0.3g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 4 hours, and then the solid product was dried at 70°C for 2 hours to obtain the terpene polymer.

[0055] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0056] 75g starch, 25g glycerol and 1.0g terpene copolymer were uniformly mixed in a container; extruded and granulated in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot-pressed in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0057] Example 6:

[0058] 1) Preparation of terpene copolymers

[0059] 10.2g of turpentine oil and 10.6g of glycidyl methacrylate were mixed, and 0.3g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 4 hours, and then the solid product was dried at 70°C for 2 hours to obtain the terpene polymer.

[0060] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0061] 75g of starch, 25g of glycerol and 2.0g of terpene copolymer were uniformly mixed in a container; extruded and granulated in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot-pressed in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0062] Example 7:

[0063] 1) Preparation of terpene copolymers

[0064] 10.2g of turpentine oil and 10.6g of glycidyl methacrylate were mixed, and 0.3g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 4 hours, and then the solid product was dried at 70°C for 2 hours to obtain the terpene polymer.

[0065] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0066] 75g starch, 25g glycerol and 3.0g terpene copolymer were uniformly mixed in a container; extruded and granulated in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot-pressed in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0067] Example 8:

[0068] 1) Preparation of terpene copolymers

[0069] 10.2g of turpentine oil and 10.6g of glycidyl methacrylate were mixed, and 0.3g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 4 hours, and then the solid product was dried at 70°C for 2 hours to obtain the terpene polymer.

[0070] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0071] 75g starch, 25g glycerol and 4.0g terpene copolymer were uniformly mixed in a container; extruded and granulated in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot-pressed in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0072] Example 9:

[0073] 1) Preparation of terpene copolymers

[0074] 10.2g of turpentine oil and 10.6g of glycidyl methacrylate were mixed, and 0.3g of azobisisobutyronitrile was added as an initiator. The mixture was refluxed at 80°C for 4 hours, and then the solid product was dried at 70°C for 2 hours to obtain the terpene polymer.

[0075] 2) Preparation of terpene copolymer-reinforced and toughened highly hydrophobic thermoplastic starch

[0076] 75g starch, 25g glycerol and 5.0g terpene copolymer were uniformly mixed in a container; extruded and granulated in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot-pressed in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0077] Comparative Example 1:

[0078] Mix 75 parts starch and 25 parts glycerol evenly in a container; extrude and granulate in a single-screw or twin-screw extruder, with the temperature of each zone of the extruder at 120℃ and the rotation speed at 25-35 r / min; hot press in a hot press at 110℃ to obtain thermoplastic starch plastic.

[0079] Table 1

[0080]

[0081] Table 1 above shows the mechanical property data of each embodiment and comparative example. The test data shows that the mechanical properties of the thermoplastic starch plastic prepared by the terpene copolymer of the present invention are significantly improved, especially the tensile strength and fracture toughness are also improved.

Claims

1. A process for the preparation of terpene copolymers and their use, characterized in that: The preparation of the terpene copolymer and its application in thermoplastic starch plastics are obtained according to the following two steps: (1) mixing turpentine and glycidyl methacrylate according to the molar ratio of 1:1, then adding 0.3 parts of azobisisobutyronitrile as initiator, refluxing at 70-80℃ for 1-4h, then drying the solid product at 70℃ for 2 hours to obtain the terpene copolymer; (2) taking 75 parts of starch, adding 25 parts of glycerol and 1.0-5.0 parts of terpene copolymer, mixing uniformly, extruding the sample in a single screw extruder, the barrel temperature is 115-125℃, the die temperature is 105-115℃, the rotating speed is 30-40r / min, hot pressing in a hot press at 110-120℃ to obtain the high hydrophobic thermoplastic starch plastic which is reinforced and toughened.

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