Porous cellulose PLA composite material and preparation method thereof
Technical Field
The invention relates to the technical field of composite materials, and particularly relates to a porous cellulose PLA composite material and a preparation method thereof.
Background
Plant fiber is a natural renewable resource, widely exists in agricultural and forestry resources and processing wastes thereof, is often not fully utilized and is abandoned as garbage in the nature. However, the plant fiber contains a large amount of hemicellulose, pectin, lignin and minerals besides a large amount of natural cellulose components, and the components can affect the performance of the composite material, so that the performance of the wood-plastic composite material is limited and difficult to be improved continuously. The cellulose has higher strength as a main component in the plant fiber, and can be used for preparing a composite material with more excellent performance. Meanwhile, the natural cellulose can be used for preparing cellulose derivatives such as methylcellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose and the like, and can be further applied to the fields of medical treatment, building materials, high-strength composite materials and the like to improve the application value again.
The plant fiber and the thermoplastic composite material are blended to prepare the environment-friendly composite material with certain biochar content, and then the plant fiber in the material contains a large amount of lignin and other components which have negative effects on the improvement of mechanical properties. If the cellulose in the plant fiber can be extracted and compounded with thermoplastic composite material, especially PLA which can be degraded by full biomass, the composite material with higher physical and mechanical properties can be prepared.
Disclosure of Invention
The invention aims to provide a porous cellulose PLA composite material aiming at the defects in the prior art, the purity of plant fibers is high, and the physical and mechanical properties of the composite material are improved.
Another object of the present invention is to provide a method for preparing the above porous cellulose PLA composite material.
The purpose of the invention is realized by the following technical scheme:
a porous cellulose PLA composite comprising the following components: porous cellulose: 20-50 parts of PLA: 40-70 parts of PBAT: 20-40 parts of antioxidant 1010.25-0.3 part, and 0.25-0.3 part of antioxidant 1076.
Further, the porous cellulose is at least one of straw fiber, wood fiber or bamboo fiber.
A preparation method of the porous cellulose PLA composite material comprises the following steps:
s1, placing plant fibers into an alkali solution for treatment, then ultrasonically cleaning the plant fibers with clear water, and drying the plant fibers to obtain porous cellulose;
s2, placing the porous cellulose, PLA, PBAT and antioxidant into a high-speed mixer to be mixed uniformly;
s3, putting the mixture obtained in the step S2 into a co-rotating parallel twin-screw extruder for extrusion and granulation to obtain the porous cellulose PLA composite material.
Further, in the step S1, the alkali solution is a NaOH solution with a pH of 10-12.
Further, the treatment time of the alkali solution in the step S1 is 4-12 hours.
Further, the temperature setting of the co-rotating parallel twin-screw extruder in step S3 is from blanking to die: 155-160-165-175-185-190 ℃.
Compared with the prior art, the invention has the following beneficial effects:
the invention mixes and granulates the porous cellulose processed by alkali liquor with PLA and PBAT to prepare the fully-degradable composite material, and the resin matrix can penetrate into the micropores of the porous cellulose to form the physical and mechanical properties of the special-shaped microstructure reinforced composite material due to the existence of the porous fiber.
Detailed Description
In order to facilitate understanding of the present invention, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the following specific examples.
Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.
Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.
Example 1
The embodiment provides a preparation method of a porous cellulose PLA composite material, which comprises the following steps:
s1, placing 30-mesh bamboo fibers into a NaOH solution with the pH value of 10 to be treated for 4 hours, and then ultrasonically cleaning the bamboo fibers with clear water and drying the bamboo fibers to obtain porous cellulose;
s2, placing the porous cellulose, PLA, PBAT and the antioxidant into a high-speed mixer to be uniformly mixed, wherein the dosage of each component is as follows: porous cellulose: 30 parts and PLA: 50 parts of PBAT: 25 parts of antioxidant 1010: 0.3 part of antioxidant: 1076:0.3 parts;
s3, putting the mixture obtained in the step S2 into a co-rotating parallel double-screw extruder for extrusion granulation, wherein the temperature is set from blanking to a die: 155-160-165-175-190 ℃ to obtain the porous cellulose PLA composite material.
The tensile strength of the composite material prepared in this example was 28.6MPa, and the flexural strength was 39.2 MPa.
Example 2
The embodiment provides a preparation method of a porous cellulose PLA composite material, which comprises the following steps:
s1, putting 30-mesh straw fibers into a NaOH solution with the pH value of 12 for treatment for 10 hours, and then ultrasonically cleaning the straw fibers with clear water and drying the straw fibers to obtain porous cellulose;
s2, placing the porous cellulose, PLA, PBAT and the antioxidant into a high-speed mixer to be uniformly mixed, wherein the dosage of each component is as follows: porous cellulose: 40 parts of PLA: 60 parts, PBAT: 30 parts of antioxidant 1010:0.25 part of antioxidant: 1076:0.25 parts;
s3, putting the mixture obtained in the step S2 into a co-rotating parallel double-screw extruder for extrusion granulation, wherein the temperature is set from blanking to a die: 155-160-165-175-190 ℃ to obtain the porous cellulose PLA composite material.
The tensile strength of the composite material prepared in this example was 27.3MPa, and the flexural strength was 42.8 MPa.
Example 3
The embodiment provides a preparation method of a porous cellulose PLA composite material, which comprises the following steps:
s1, placing 30-mesh straw fibers and wood fibers into a NaOH solution with the pH value of 12 for treatment for 12 hours, wherein the ratio of the two fibers is 1:1, and then ultrasonically cleaning the two fibers with clear water and drying the two fibers to obtain porous cellulose;
s2, placing the porous cellulose, PLA, PBAT and the antioxidant into a high-speed mixer to be uniformly mixed, wherein the dosage of each component is as follows: porous cellulose: 20 parts of PLA: 70 parts, PBAT: 20 parts of antioxidant 1010: 0.3 part of antioxidant: 1076:0.25 parts;
s3, putting the mixture obtained in the step S2 into a co-rotating parallel double-screw extruder for extrusion granulation, wherein the temperature is set from blanking to a die: 155-160-165-175-190 ℃ to obtain the porous cellulose PLA composite material.
The tensile strength of the composite material prepared in this example was 26.5MPa, and the flexural strength was 44.7 MPa.
It should be understood that the above examples are only for clearly illustrating the technical solutions of the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.