Plastic experiment ① (Making plastic / plastic fiber from milk, etc.)
Plastic has become a necessity due to its durability and ease of molding. On the other hand, the difficulty of processing is a problem. This time, we will make casein plastic, which is one of the biodegradable plastics.
Experiment 1: Casein plastic made from milk
you need : 200 ml of milk, 20 ml of vinegar, gauze, microwave
Heat 200 ml of milk to 60-70 ° and add 20 ml of vinegar to denature the proteins in the milk. The cottage cheese is made by rubbing this.
Biodegradable casein plastic is made by heating this cottage cheese in a microwave oven several times and hardening it. It is strong enough and has the advantage that it will be decomposed if it is buried in the soil.
I should go with congratulations and congratulations, but there are a lot of problems. The cost is high when actually using it. Biodegradable plastics, which had been multiplied several times around 2000, now have a cost difference of several tens of percent depending on the product. Also, many biodegradable plastics are made from starch in grains such as corn. Carbon dioxide emissions and food issues must also be considered during the manufacturing process. PVA is a petroleum-derived plastic, but it is biodegradable. It is being researched from various directions.
Experiment 2: Let's take out the fiber from the plastic.
you need : PP (polypropylene) straw, tapered glass tube, tweezers
Tape the glass tube. Lightly burn with a burner. Put a PP straw there, and when the tip comes out, pull it with tweezers at once. It stretches lightly for 5 or 6 m. This encourages students to think about how useful plastic is, as well as to look at current problems and think about how to solve them. For recycling, please go to other Plastic Experiment .
Experiment 3: Compressed wood that can be used like plastic
Wood can be deformed quite freely when heated. It is one toy that uses it.
you need : disposable chopsticks (wood), beaker, hot water, 5-yen coin, needle-nose pliers
Make an arrow shape out of wood. Soak in hot water for a minute or two to soften it. Pass it through the 5-yen coin while crushing it with needle-nose pliers. done. Originally, it is softened with steam in consideration of drying. Compressed wood is 1/4 the original size. Due to its excellent resistance and increased strength, it is used in various places such as places where wood cannot be used originally. Conifers in particular are stronger. After all the problem is cost.
Example of using compressed wood
Due to its properties, compressed wood can be used like tiles or withstand long-term outdoor use. Therefore, I want to think flexibly, not plastic.
Nagoya Lumber Co., Ltd. Woody Craft Co., Ltd.