Enzyme-treated plant fiber reinforced degradable composite material and preparation process thereof

Abstract

The invention relates to the field of modified degradable composite materials, in particular to an enzyme-treated plant fiber reinforced degradable composite material and a preparation process thereof.The enzyme-treated plant fiber reinforced degradable composite material is prepared from, by weight, 80%-99% of degradable high-molecular polymer and 1%-20% of modified plant fiber, and the preparation process comprises the steps that waste plant fiber is subjected to high-temperature water bath heat treatment in a constant-temperature water bath kettle; the temperature is controlled to be 80-100 DEG C, and the time is controlled to be 2-2.5 h; putting the obtained plant fibers into a constant-temperature water bath stirring pot containing an enzyme solution, and carrying out enzyme treatment for 5-6 hours at the temperature of 50-55 DEG C and the rotating speed of a stirrer of 300-500 r / min; the obtained plant fibers are washed with distilled water for 2-3 min and then dried, and modified plant fibers are obtained; uniformly mixing the obtained dried modified plant fibers with a high-molecular polymer in proportion; and putting the obtained mixture into a mold, and preparing the composite material through a plate vulcanizing machine. The resource utilization of the waste plant fibers is realized, and the environmental pollution is reduced.

Description

Technical Field

[0001] The invention relates to the field of modified degradable composite materials, and in particular to an enzyme-treated plant fiber-reinforced degradable composite material and a preparation process thereof. Background Art

[0002] At present, the methods for treating agricultural by-products mainly include direct incineration, composting, feed and straw return to the field. Among them, incineration is particularly common and is a common cleaning method in rural areas. However, these current treatment methods have certain limitations. Direct incineration will produce a lot of smoke and harmful gases, and even cause fire risks; the composting process is slow and is greatly affected by climatic conditions, making it difficult to meet the needs of large-scale treatment; the feed utilization rate is low, and not all straw is suitable as feed; and in the process of returning straw to the field, excessive return to the field may lead to soil environmental deterioration and the occurrence of pests and diseases. Therefore, it is of great practical significance to find a more environmentally friendly and efficient method for treating agricultural by-products. From the perspective of materials, natural fiber is a natural plastic reinforcement material. If it can be simply processed and fully and effectively utilized, it will not only protect the ecological environment but also have great significance for the development of a green circular economy. Summary of the invention

[0003] In order to solve the above problems, an enzyme-treated plant fiber reinforced biodegradable composite material and a preparation process thereof are provided. By treating waste plant fibers to obtain modified plant fibers, the modified plants fibers are mixed with biodegradable high molecular polymers and made into reinforced biodegradable composite materials, thereby realizing resource utilization of waste plant fibers and reducing environmental pollution.

[0004] In order to solve the problems of the prior art, the present invention provides an enzyme-treated plant fiber reinforced degradable composite material, characterized in that it comprises 80% to 99% of a degradable high molecular polymer and 1% to 20% of modified plant fiber in weight percentage.

[0005] Preferably, the modified plant fiber is obtained by subjecting waste plant fiber to high-temperature water bath treatment and enzyme treatment.

[0006] Preferably, the waste plant fibers include fibers from plant roots, stems, leaves or husks.

[0007] Preferably, the waste plant fiber is one or more of straw fiber, peanut shell fiber and coconut shell fiber.

[0008] Preferably, the degradable high molecular polymer is one or more of polylactic acid and polybutylene succinate.

[0009] A method for preparing an enzyme-treated plant fiber-reinforced degradable composite material comprises the following steps: Step (1), subjecting the waste plant fibers to a high-temperature water bath heat treatment in a constant temperature water bath, with the temperature controlled at 80°C to 100°C and the time controlled at 2h to 2.5h; Step (2), placing the plant fiber obtained in step (1) into a constant temperature water bath stirring pot containing an enzyme solution, the temperature is set at 50°C to 55°C, the speed of the stirrer is 300r / min to 500r / min, and the enzyme treatment is carried out for 5h to 6h; Step (3), washing the plant fiber obtained in step (2) with distilled water for 2 to 3 minutes and then drying it to obtain modified plant fiber; Step (4), uniformly mixing the dried modified plant fiber obtained in step (3) with the high molecular polymer in proportion; Step (5), placing the mixture obtained in step (4) into a mold and subjecting it to a flat vulcanizer to prepare a composite material.

[0010] Preferably, the temperature of the plate vulcanizer is set between 175° C. and 185° C., the pressure is set between 2 MPa and 4 MPa, the exhaust is performed 2-3 times, and the molding time is 12 min to 15 min.

[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention directly utilizes waste plant fibers, does not require excessive requirements for waste plant fibers, and has a wide range of applications. At the same time, the high-temperature water bath step can not only remove impurities on the surface of the plant fibers, but also inactivate the plant fiber cells and accelerate the reaction efficiency of the enzyme solution and the plant fibers. This method reduces manufacturing costs and improves production efficiency.

[0012] (2) The present invention uses waste plant fibers as reinforcing materials for composite materials, which can not only reduce the high price of biodegradable polymers in composite materials, but also turn waste into treasure, providing a way to achieve resource recycling.

[0013] (3) The present invention will not cause any pollution to the environment throughout the entire process. At the same time, the prepared composite material can also replace traditional non-degradable materials, providing a new method for protecting the natural environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention provides a comparative diagram of tensile strength test data of three groups of embodiments and comparative examples of an enzyme-treated plant fiber reinforced degradable composite material.

[0015] Figure 2 The present invention provides a comparative diagram of bending strength test data of three groups of embodiments and a comparative example of an enzyme-treated plant fiber reinforced degradable composite material.

[0016] Figure 3The present invention provides a comparative diagram of impact strength test data of three groups of embodiments and a comparative example of an enzyme-treated plant fiber reinforced degradable composite material. DETAILED DESCRIPTION

[0017] In order to further understand the features, technical means, specific objectives and functions of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0018] An enzyme-treated plant fiber reinforced degradable composite material, characterized in that it comprises 80% to 99% of a degradable high molecular polymer and 1% to 20% of modified plant fiber in weight percentage.

[0019] The modified plant fiber is obtained by treating the waste plant fiber with a high temperature water bath and an enzyme. Specifically, the waste plant fiber is pretreated in a high temperature water bath environment. The waste plant fibers include fibers from plant roots, stems, leaves or fruit shells.

[0020] The waste plant fiber is one or more of straw fiber, peanut shell fiber and coconut shell fiber.

[0021] The degradable high molecular polymer is one or more of polylactic acid and polybutylene succinate.

[0022] A method for preparing an enzyme-treated plant fiber-reinforced degradable composite material comprises the following steps: Step (1), subjecting the waste plant fibers to a high-temperature water bath heat treatment in a constant temperature water bath, with the temperature controlled at 80°C to 100°C and the time controlled at 2h to 2.5h; Step (2), placing the plant fiber obtained in step (1) into a constant temperature water bath stirring pot containing an enzyme solution, the temperature is set at 50°C to 55°C, the speed of the stirrer is 300r / min to 500r / min, and the enzyme treatment is carried out for 5h to 6h; Step (3), washing the plant fiber obtained in step (2) with distilled water for 2 to 3 minutes and then drying it to obtain modified plant fiber; Step (4), uniformly mixing the dried modified plant fiber obtained in step (3) with the high molecular polymer in proportion; Step (5), placing the mixture obtained in step (4) into a mold and subjecting it to a flat vulcanizer to prepare a composite material.

[0023] The temperature of the flat vulcanizer is set between 175° C. and 185° C., the pressure is set between 2MPa and 4MPa, the exhaust is performed 2-3 times, and the molding time is 12min to 15min.

[0024] Example 1 Step 1: Heat-treat the coconut shell fiber in a constant temperature water bath at 90°C for 2 hours.

[0025] Step 2: Place the plant fiber obtained in step 1 into a constant temperature water bath stirring pot containing 5% amylase solution, set the temperature to 55°C, and the speed of the stirrer to 400 r / min for enzyme treatment for 5 hours.

[0026] Step 3: Rinse the plant fiber obtained in step 2 with distilled water for 2 to 3 minutes and then dry it.

[0027] Step 4: The dried plant fiber obtained in step 3 is mixed according to the mass fraction, 2% plant fiber and 98% polylactic acid, and the mixture is placed in a mold and prepared by a flat vulcanizer. The temperature of the flat vulcanizer is set to 180° C., the pressure is set to 2MPa-4MPa, the exhaust is performed 3 times, and the molding time is 14.5 min to obtain an enzyme-treated plant fiber reinforced composite material.

[0028] Example 2 The difference from Example 1 is that 4% of plant fiber and 96% of polylactic acid are mixed.

[0029] Example 3 The difference from Example 1 is that 6% of plant fiber and 94% of polylactic acid are mixed.

[0030] Comparative Example 1 The difference from Example 1 is that no enzyme solution treatment is performed.

[0031] Comparative Example 2 The difference from Example 2 is that no enzyme solution treatment is performed.

[0032] Comparative Example 3 The difference from Example 3 is that no enzyme solution treatment is performed.

[0033] The composite materials prepared in the examples and comparative examples were prepared into samples according to GB / T 1446-2002, the tensile strength of the composite materials was tested according to GB / T1040-2006, the flexural strength of the composite materials was tested according to GB / T1449-2005, and the impact strength of the composite materials was tested according to GB / T1451-2005. Figure 1 , Figure 2 and Figure 3 They are comparison charts of test data respectively.

[0034] Experimental data summary table: project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile strength MPa 22.57 33.39 23.54 3.65 7.22 14.89 Bending strength MPa 55.04 76.78 44.74 15.56 16.59 30.87 Impact strength KJ / m2 22.33 17.90 16.41 7.16 10.04 14.88 The above embodiments only express one or several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. An enzyme-treated plant fiber reinforced biodegradable composite material, characterized in that: The composition comprises 80% to 99% of degradable macromolecular polymer and 1% to 20% of modified plant fiber in terms of weight percentage.

2. The enzyme-treated plant fiber reinforced degradable composite material according to claim 1, characterized in that: The modified plant fiber is obtained by subjecting waste plant fiber to high-temperature water bath treatment and enzyme treatment.

3. The enzyme-treated plant fiber reinforced degradable composite material according to claim 1, characterized in that: The waste plant fibers include fibers from plant roots, stems, leaves or fruit shells.

4. The enzyme-treated plant fiber reinforced degradable composite material according to claim 3, characterized in that: The waste plant fiber is one or more of straw fiber, peanut shell fiber and coconut shell fiber.

5. The enzyme-treated plant fiber reinforced degradable composite material according to claim 1, characterized in that: The degradable high molecular polymer is one or more of polylactic acid and polybutylene succinate.

6. A method for preparing an enzyme-treated plant fiber-reinforced degradable composite material, characterized in that: The steps include: Step (1), subjecting the waste plant fibers to a high-temperature water bath heat treatment in a constant temperature water bath, with the temperature controlled at 80°C to 100°C and the time controlled at 2h to 2.5h; Step (2), placing the plant fiber obtained in step (1) into a constant temperature water bath stirring pot containing an enzyme solution, the temperature is set at 50°C to 55°C, the speed of the stirrer is 300r / min to 500r / min, and the enzyme treatment is carried out for 5h to 6h; Step (3), washing the plant fiber obtained in step (2) with distilled water for 2 to 3 minutes and then drying it to obtain modified plant fiber; Step (4), uniformly mixing the dried modified plant fiber obtained in step (3) with the high molecular polymer in proportion; Step (5), placing the mixture obtained in step (4) into a mold and subjecting it to a flat vulcanizer to prepare a composite material.

7. The method for preparing an enzyme-treated plant fiber-reinforced degradable composite material according to claim 6, characterized in that: The temperature of the flat vulcanizer is set between 175° C. and 185° C., the pressure is set between 2MPa and 4MPa, the exhaust is performed 2-3 times, and the molding time is 12min to 15min.

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