CN100355561C - Biodegradable waterproof artificial floating island - Google Patents

Abstract

A biodegradable waterproof artificial floating island material made of wheat straw and rice straw as the main raw material is characterized in that maleic anhydride is used as a degreasing agent, tung oil or polyurethane waterproof coating is used as a waterproofing agent, and diphenylmethane diisocyanate is Adhesive, lime and cement are plasticizers, which are made after paving and hot pressing. It is a new type of medium material for artificial floating islands, which is suitable for use in water bodies, has good safety and is easy to popularize.

Description

A biodegradable waterproof artificial floating island material

1. Technical field

The invention belongs to the field of development of new materials for waterproofing and water pollution control, and the product relates to the processing technology of wood-based panels or similar materials, and at the same time relates to the processing and utilization technology of crop straws.

2. Background technology

In recent years, as people have paid more and more attention to environmental issues, the surrounding natural environment, especially the natural landscape of the waterside, has also received more and more attention. Artificial floating island technology for sexual ecosystems also holds great promise. The main functions of artificial floating islands can be summarized into four aspects:

1. Water purification;

2. Create living space for creatures (birds, fish);

3. Improve the landscape;

4. Wave dissipation effect, the artificial floating island can protect the shore base.

Therefore, artificial floating island technology is currently widely used in reservoirs with large fluctuations in water level, or in lakes and marshes where it is difficult to restore the aquatic vegetation belt on the shore due to waves, or in closed waters such as ponds with landscape requirements.

In the selection of floating carriers and substrates for artificial floating islands, the mainstream materials used at home and abroad are usually natural materials such as wood, bamboo, polystyrene, polyurethane foam or sponge, or polymer organic synthetic materials.

Artificial floating islands can be divided into dry type and wet type according to different needs. Due to the fact that the plants do not directly contact the water body, the dry floating island can cultivate large woody and horticultural plants. Through the combination of different woody plants, a good habitat for birds is formed, and the landscape is also beautified; the direct contact between the water body and the plants is It is a wet artificial floating island, and the wet artificial floating island can be divided into two types: framed and frameless. For the wet floating island with frame, its frame can generally be made of materials such as wood, bamboo, fiber reinforced plastic, stainless steel plus expanded polystyrene, special expanded polystyrene plus special synthetic resin, salinized vinyl synthetic resin, and concrete. Frameless wet floating islands can generally be woven with coconut fiber. Because the edges are softer, they are not afraid of mutual impact and damage to the shore base, and their durability is also good. Synthetic fiber is also used as the base plate of the plant, and then wrapped with synthetic resin, fixed into an engineering example of a frameless wet floating island.

Due to the low price and abundant sources, polystyrene foam materials are widely used in the floating carriers of artificial floating islands. However, polystyrene foam will precipitate toxic substances when heated, and if it is placed in water for a long time, it will cause great harm to the health of people and aquatic organisms in contact with water. In the natural environment, even after hundreds of years, polystyrene foam cannot be biodegraded and participate in the biological cycle, thus becoming a new source of pollution.

In recent years, some companies have studied the use of natural materials such as coconut shells and ceramsite as floating materials for floating islands. However, due to resource and cost constraints, it is more difficult to fully promote. Therefore, the development and production of low-cost, easy-to-use, and biodegradable artificial floating island materials has practical environmental protection significance, and the reuse of agricultural organic waste is meeting this requirement.

Now, using natural polymers such as starch, cellulose, chitosan and konjac glucomannan as the main raw materials to develop biodegradable sheets, pellets and film materials has been listed as a field of degradable plastics by many countries in the world. research focus. American Warner & Lambert Company announced in 1995 that w (starch) > 90% biodegradable polymers had been developed through the isomerization of starch. Later, researchers at the University of Illinois in the United States developed a new biodegradable material-corn plastic; Japan also developed excellent film materials using modified starch and konjac powder as raw materials. In 2002, Teng Cuiqing and others in my country used cheap straw as a reinforcing material and starch as a matrix material to prepare disposable biodegradable flowerpots through compression molding; Wu Jun et al. used dry modified starch as the main raw material in 2001. V (glycerol): V (ethylene glycol) = 1: 2 composite plasticizer plasticization, adding enhancer PX and solubilizer EAA, after blending, starch-based thermoplastic biodegradable plastics can be developed. Studies have shown that w (modified starch) in the plastic is 50% to 70%, and other additives can also be biodegradable and have good mechanical properties.

In recent years, there has been a lot of research on the production of biodegradable plastics by using transgenic plants. Poly-β-hydroxybutyric acid (PHB) and spidroin are all biodegradable plastics and have broad application prospects. Although the use of transgenic plants to produce biodegradable plastics has made great progress, the content of biodegradable plastics synthesized in transgenic plants is still very low, far from meeting the requirements of commercial production, and there are still a series of problems. Side effects for plant growth.

At present, most of the wood-based panel materials that use wood as the main raw material are only suitable for use in dry environments. Once placed in water bodies, they will quickly undergo serious deformation or even rot; It is easy to deform even in a humid environment. Therefore, the existing wood-based panel products cannot meet the increasing needs of water environment treatment materials.

Therefore, it is an urgent task to develop and research new artificial floating island medium materials that are suitable for use in water bodies, safe, and easy to promote.

3. Contents of the invention

The purpose of the present invention is to develop a biodegradable water tank made of crop waste--straw as the main raw material in order to meet the special requirements for the floating carrier and matrix material of the artificial floating island in the improvement and beautification project of the water environment. Waterproof artificial floating island material.

The technical solution of the present invention is: using wheat straw and rice straw as the main raw materials, through improving the selection of adhesive formula, the selection of additives and the pretreatment of materials in the existing wood-based panel production technology, a new type of The biodegradable waterproof artificial floating island material is characterized by:

a. Adopt maleic anhydride as the degreasing agent of raw material;

b. Use tung oil or polyurethane waterproof coating as waterproofing agent;

c. Using diphenylmethane diisocyanate as the adhesive;

d. The surface layer 1 uses cut short wheat straw, and the core layer 2 uses crushed straw.

In order to improve the strength of the finished product, an appropriate amount of lime or cement can be added as a plasticizer to the surface and core materials.

4. Description of drawings

Fig. 1 is a schematic diagram of the assembly structure of the biodegradable waterproof artificial floating island material. In the figure, 1 is the surface layer, which is made of cut short wheat straw (about 1 to 3 cm long) mixed with glue and paved; 2 is the core layer, which is made of crushed straw mixed with glue and paved.

5. Specific implementation

Example 1:

Stir and soak the straw and wheat straw with maleic anhydride (chemically pure) aqueous solution of 5-15% by weight for 8-24 hours; remove, air-dry, and dry at 103±2°C until the water content is ≤8 %. Use a pulverizer to crush the straws into fragments, fine enough to pass through a 10-20 mesh sieve; use a shearer to cut the wheat straws into short straws with a length of 1-3 cm.

Put 1 kg of short wheat straw into the blender, add 5-10% tung oil (industrial grade) according to the weight of the straw, and stir well, then add 3%-5% diphenylmethane according to the weight of the straw Diisocyanate (MDI) (chemically pure); after fully stirring, turn it out for later use.

Put 5kg of straw scraps into the blender, add 3% to 5% of tung oil according to the weight of the straw scraps, and stir well, then add 5% to 10% of diphenylmethane according to the weight of the straw scraps Diisocyanate (MDI), after fully stirring, transfer out for later use.

The slab surface layer 1 is paved with short wheat straw after sizing, and the slab core layer 2 is paved with straw scraps after sizing. The pressing process parameters are: hot pressing temperature: 160~180°C; hot pressing pressure: unit pressure 5~8MPa; hot pressing time: 20~45s/mm. After the hot pressing is completed, the biodegradable waterproof artificial floating island material can be obtained by cooling, trimming and grinding.

Example 2:

In order to improve the strength of the finished product, when the dried raw material is mixed with tung oil, 2-5% by weight of powdered dry lime or cement can be added as a plasticizer at the same time.

All the other are with embodiment 1.

Example 3:

As described in Example 1, tung oil can be replaced by an equal amount of two-component asphalt-modified polyurethane waterproof coating (reference standard: JC500-1992 "polyurethane waterproof coating").

The main physical performance indicators of the biodegradable waterproof artificial floating island material provided by the present invention are as follows:

1. Thickness: 0.50～150mm

2. Density: 0.40～0.95g/ ^cm3

3. 24 hours immersion expansion rate: 2% ~ 10%

4. Internal bonding strength: ≥0.60MPa

Because the biodegradable waterproof artificial floating island material provided by the present invention, its main raw material straw straw and wheat straw are natural biodegradable materials, therefore, it can be used as artificial floating carrier and The matrix not only has high strength and good waterproof performance, but also avoids pollution to water bodies and the environment.

Claims (5)

1. one kind is the biodegradable waterproof artificial floating island that primary raw material is made with wheat straw stalk, straw, is made of surface layer 1 and sandwich layer 2, it is characterized in that:

A. adopt the degreasing agent of maleic anhydride as raw material;

B. adopt tung oil or polyurethane water-proof paint as waterproofing agent;

C. adopting methyl diphenylene diisocyanate is adhesive;

D. surface layer 1 uses the short wheat straw stalk that cuts off, and sandwich layer 2 uses the straw of pulverizing.

2. biodegradable waterproof artificial floating island as claimed in claim 1, when it is characterized in that wheat straw stalk, straw carried out degreasing and soak, the weight percent concentration of its aqueous solution is 5%～15%, stirring soak time is 8～24 hours.

3. biodegradable waterproof artificial floating island as claimed in claim 1, when it is characterized in that preparing surface layer 1, adding is 5%～10% tung oil or polyurethane water-proof paint by weight in the wheat straw stalk after degreasing, drying, the cut-out; During preparation sandwich layer 2, adding is 3%～5% tung oil or polyurethane water-proof paint by weight in the straw after degreasing, drying, the pulverizing.

4. biodegradable waterproof artificial floating island as claimed in claim 1, when it is characterized in that preparing surface layer 1, adding is 3%～5% methyl diphenylene diisocyanate by weight in the wheat straw stalk after degreasing, drying and the cut-out; During preparation sandwich layer 2, adding is 5%～10% methyl diphenylene diisocyanate by weight in the straw after degreasing, drying and the pulverizing.

5. biodegradable waterproof artificial floating island as claimed in claim 1 is characterized in that in surface layer and core material adding percentage by weight and is 2～5% powdery dry lime or cement and makes plasticizer.

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