Production of composite materials using biodegradable resin and reed cellulose

Reed (scientific name: phragmites comunis (cave.) trin. exoud.) is a perennial aquatic or wetland tall grass with well-developed rhizomes. The stem is upright, 1-3 meters high, with over 20 nodes. Reed is a diverse species widely distributed worldwide. Born along rivers, lakes, marshes, ponds, ditches, and low-lying wetlands. For example, in the Bosten Lake in Xinjiang, there are a large number of reeds that have been abandoned, causing problems such as eutrophication of the water body; Reed contains a large amount of reed cellulose, which is one of the good raw materials for preparing biomaterials.

The development of organic polymer materials has played an important role in human society, but most organic polymer materials have almost no biodegradability, making environmental pollution increasingly serious. Therefore, there is an urgent need to design biodegradable materials. It is difficult to balance the performance of biodegradable materials while designing and emphasizing their degradability, or in some cases, sacrificing the performance of materials may be necessary. This makes it difficult for existing biodegradable material systems to meet the needs of multiple surfaces simultaneously. At the same time, considering cost, biodegradable materials are difficult to be widely used.

Reed is a naturally growing plant with readily available raw materials and low prices. Therefore, using reed as a biodegradable composite material is a new research direction and rotation. However, in the research and development process of this reed biodegradable composite material, the following technical challenges need to be addressed:

1. The molecular types and polarities of biodegradable resins and reed cellulose in the production of composite materials have significant differences, and the forces between the two are difficult to convert into covalent or ionic bond forces in chemical changes. Moreover, due to the large gaps between the materials, Newtonian gravity is far from meeting the requirements of product strength. Therefore, by making the intermolecular forces between the two substances as strong as possible in the microscopic space, better product performance can be achieved.

2. The affinity between fully biodegradable substances and whole substances is poor. Taking starch, reed, and polybutylene succinate (PBS) as examples, the former is a strongly polar molecule, while the latter is a non-polar molecule. The two are not compatible or compatible, but rather hydrophobic and separable, with a single form of intermolecular force and extremely small force.

Technical implementation elements: The purpose of the present invention is to provide a reed biodegradable composite material. To achieve the above objectives, one embodiment of the present invention provides a reed biodegradable composite material, comprising the following raw material components in a mass fraction ratio: 15 to 50 parts of reed crushed material, with an average diameter of 5 to 15 micrometers after reed crushing; 15 to 30 parts of modified starch; 10 to 50 parts of biodegradable resin; 0.5 to 1 part of coupling agent; 1 to 10 parts of active agent; 1 to 3 parts of degradation complex enzyme; 1 to 3 parts of degradation cycle regulator; The degradation complex enzyme is selected from one or a mixture of oxidoreductases, lyases, transferases, isomerases, synthases, sucrases, glutamate dehydrogenases, amylases, or dehydroascorbic acid; The degradation cycle regulator is selected from a mixture of one or more of diisopropylbenzene oxide (dcp), methyl ethyl ketone peroxide (mekp), 2,2,2, di (tert butyl peroxide) butane (dbpb), or tert butyl benzoate peroxide (bpb).

In the optimization scheme of the present invention, the reed biodegradable composite material comprises the following raw material components in a mass fraction ratio: 30 parts of reed crushed material, with an average diameter of 10 microns after reed crushing; 25 parts of modified starch; 35 parts of biodegradable resin; 0.6 parts of coupling agent; 5 parts of active agent; 2 parts of degradation complex enzyme; 2 parts of degradation cycle regulator. Preferably, the raw material components also include initiators and auto oxidants. The preferred modified starch is a mixture of one or more modified starches from corn modified starch, potato modified starch, wheat modified starch, and cassava modified starch. The preferred biodegradable resin is one or more mixtures of polyurethane resin, polycaprolactone resin, polylactic acid resin, polybutylene succinate resin, and polyhydroxybutyrate. The preferred coupling agent is one or a mixture of silane coupling agent or titanate coupling agent. The preferred active agents are dodecyl betaine, oleic acid, laurel dimethyl amine oxide, or lauric acid.

The use of each component in the present invention:

1. The reed of the present invention, as a filling agent, can naturally decompose and be crushed and refined during use. The crushed reed material with a mesh size of 800 to 2000 mesh is obtained through mesh classification; The moisture content in processed reeds is less than or equal to 3%.

2. The starch of the present invention can be naturally degraded, and the present invention causes the physical properties of the entire material to collapse through the biodegradation of starch, leading to the exposure of a large number of end groups and oxidative degradation.

3. The coupling agent of the present invention is a type of substance with two different functional groups, and its molecular structure is characterized by the presence of two groups with different chemical properties in the molecule. One is a group that is hydrophilic to inorganic substances and easily reacts with the surface of inorganic substances; The other is an organic group that can react chemically or form hydrogen bonds with synthetic resins or other polymers and dissolve in them. Therefore, the addition of coupling agents in the present invention can improve the interfacial properties of degradable resins, inorganic fillers, and reinforcing materials, and can enhance the interfacial interaction between inorganic and organic substances, thereby greatly improving the performance of composite materials, such as physical properties, electrical properties, thermal properties, optical properties, etc.

4. The active agent of the present invention can improve the dispersibility of the mixed materials, making the phase of the mixed materials uniform.

5. The biodegradable resin of the present invention can be completely degraded in the environment through the combined action of oxidation, light, and biology, without causing pollution to the environment.