Length materials and appliances
Specimens (insects, plants, etc.) ), formaldehyde, urea, glacial acetic acid, 25% NaOH solution, colored ink, balance (or scale), electric stove (or other heat source), water bath pot (or ordinary pot), iron shelf, iron clip, medicine spoon, measuring cylinder, conical flask, warm juice, glass rod, plastic mold and dryer.
2. Method steps
(1) May ~ 10 should be selected every year, when the ambient temperature is high and the resin synthesis speed is fast.
(2) Prepare urea-formaldehyde monomer, take 63g urea and 180ml formaldehyde, put them in a conical flask, and add 5 drops of 25% NaOH solution to stir. Heat quickly in a water bath. When the temperature rises to 90℃, add 30 drops of glacial acetic acid. When the temperature rises to 100℃, stop heating. Keep the reaction temperature (above 95℃) for 5min, and then continue heating. Immerse the liquid in clear water with a glass rod. When the liquid drops disperse in a cloud shape, immediately add 30 drops of 25% NaOH solution and stop heating. Add 1 drop of color ink to make color urea-formaldehyde monomer. Urea-formaldehyde monomer is far away from strong acid and alkali. Storage time shall not exceed 50 days.
(3) Synthetic resin Take 20 parts of urea-formaldehyde monomer, add 1 part of glacial acetic acid, mix and fully stir to polymerize into urea-formaldehyde resin. Dolphin aldehyde resin should be synthesized the day before pouring the bottom plate, embedding the specimen or covering the top plate. Let it stand for one day after synthesis to remove bubbles and impurities.
(4) The pouring bottom plate should be made of a plastic mold with a certain hardness that does not react with urea-formaldehyde resin, and the surface of the mold should be smooth. The size of the mold depends on the size of the specimen, which is slightly larger than the specimen. Wipe the mold clean before pouring the bottom plate. When casting, the urea-formaldehyde resin synthesized the day before was poured into the mold along the glass rod. The thickness shall not exceed 5mm, and the bottom plate shall be put into the dryer after pouring.
(5) On the third day after the embedded samples are poured on the bottom plate, the fresh samples (such as insects, plants, etc.) collected in advance are soaked in the newly prepared urea-formaldehyde resin. Attention should be paid to posing in time, and plant specimens should be color-preserved before embedding. On the fourth day, the bottom plate in the mold hardened. At this point, put the above specimen on the bottom plate and then put it back in the dryer. After 2 days, the specimen was firmly adhered to the bottom plate, and then the specimen was embedded. It is advisable to pour the resin no more than 5mm at a time, and put it into the dryer after pouring. After 3 days, when the resin hardens, the second and third layers are poured again ... This process is repeated until all specimens are embedded. But if it is a LEPIDOPTERA specimen, the dam must be embedded at one time.
(6) After all specimens of the top cover are sealed and buried, the upper resin hardens, then the top layer of 5mm is poured and put into the dryer. When the specimen is hardened and pressed without imprint, the amber specimen is taken out of the mold.
(7) Tissue Specimens Amber specimens made by this method are crystal clear and lifelike. Generally, you only need to modify the edges slightly. Conditional mold polishing effect is better.
(8) Save the specimen. Store amber in a special specimen box. Avoid contact with strong acid and alkali during storage and keep the air dry.