Learning with homemade soap Chemistry course that is really friendly to the environment and health
Early 2015 Nagoya Environmental University Co-education lecture Kiyoyuku (May, Heisei 20)
Learning here is about not only about soap but also basic knowledge of chemistry for greases and environments that are widely useful for health.
1) Science and the environment
There is only one earth, plants, animals, and humans live. Activity is also indispensable for human life by obtaining food with agriculture. The farming is also done on a worldwide basis, not a local pond disappearing like the old, but many foods are imported from abroad. Also, when you consume them you get garbage. For such human life, grease and soap to wash it are essential items.
1-1) Food self-sufficiency rate
While there are food exporting countries whose main countries' food self-sufficiency ratio exceeds 100%, Japan has fallen to a very low self-sufficiency rate of around 39%. It is also manifesting as a figure of reality self-sufficiency that fields and rural landscapes have disappeared from personal belongings. A decline in the self-sufficiency rate means that imports of food from overseas are increasing.
1-2) Food mileage
Here I will explain the concept of food mileage. Food mileage is the number of food consumed (weight) × distance traveled (Km). It is an indicator of how far from the local production pond disappears how far you are eating the food you have brought from far. Looking at the figure below, Japan knows that food mileage is also very big in the world. There are also many population living in a narrow country. Food mileage is also big in South Korea where the country is narrow, but it is not as much as Japan. France, which is an agricultural country, has a small value. The country is small UK, Germany, which is an industrialized country, also has a smaller food mileage than Japan.
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2) Chemistry of soap
Now that I have found the outline of Japanese food situation, the next is about fat and oil of soap material. Soap materials are oil and caustic soda and water. In addition to natural fats and oils, oils and fats can also be used as fatty acids derived from petroleum. Caustic soda is a strong alkaline chemical among the "acid / alkali" categories. Sodium bicarbonate is representative in alkali in daily life. Sodium bicarbonate and caustic soda contain the same mineral as sodium.
2-1) Carbon
Mixing grease, caustic soda and water produces a byproduct of soap and glycerin. Carbon C (carbon) is indispensable when considering the chemical formula of oils and fats. As you can see from the fact that charcoal (soot) can be produced by burning fats and oils, it is made up of gatherings of carbon and others. Carbon occupies most of the body of plants that have taken up carbon dioxide in the air. Let's remember carbon is the material of plants and animals.
2-2) Caustic soda
Well, another material of soap was caustic soda. Caustic is a word meaning that the skin becomes rough, and soda is sodium. Sodium is a mineral component of salt. It is an essential mineral contained in seawater and the body. It has properties which are easily soluble in water. The reaction of mixing hydrochloric acid and caustic soda is a reaction of acid alkali. I can make salt and water. It is strange a little.
2-3) Oil and fat
Fats and oils refer to the oil in general, which is used everyday, including liquid oil and fat solidified at room temperature. Materials such as soybean oil, palm oil, rapeseed oil, etc. are produced in large quantities. Especially olive oil and Laurel oil etc are used in Europe for a long time and are also famous as a material for soap. Petroleum and coal are said to have originated from the carcass of plants and animal carcasses in the soil. Petroleum coal refining oil and rapeseed oil oil have the same chemical structure. Nevertheless, rapeseed is much better than oil that can be regenerated in the sunlight in a year, petroleum coal has been in the past several hundred million years
There is also a difference that it uses the oil of animals and plants that have been exposed to sunlight for many years such as momentarily. Any oil will mix unpurified impurities. It is called impurities or trace ingredients. Anxiety remains in such impurities in petroleum and coal derived oils. On the other hand, it is said that some trace components of renewable vegetable oil such as olive oil can be expected to have a good scent and a good effect on the skin, which is heavily used.
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2-4) Plantation
Palm oil and the like are oils like representatives of renewable energy which can be harvested 12 times a year in vegetable oils and has high production volume. However, it opened up a rainforest in Southeast Asia such as Malaysia and Indonesia and created a huge plantation that cultivates only a single variety called plantation. Global warming has been accelerated by the plantation. Local life farmers' lives have not necessarily become wealthy. There are aspects that press the circumstances of European and American developed countries to Southeast Asia and others.
3) Health and the environment
3-1) Oils and fats and health
Well, if we look at this oil in relation to health, it is the balance of the three major nutrients, P protein, F fat, C sugar. Dietary habits such as America and France take too much fat and in Vietnam and Thailand it seems like taking too much sugar. I think that it can be said that the balance of protein, fat, and saccharide is superior in Japan's dietary life.
3-2) Soap and environment
Talk to soap and think about the relationship with the environment. Soap removes grease so it is essential to life. The soap-containing water flows back into the river and then returns to the original water after biodegradation by microorganisms. Microorganisms eat soap and break down. Synthesis in soap
Soap LAS is what used to be. With synthetic soap, the shape of the molecule did not branch and it was linear soap. It turns out that in the graph, it takes time to be biodegraded. This was also improved by making branched synthetic soap.
Also, the soap of natural ingredients is easy to biodegrade and looks good to the environment. This is also a numeric magic, it is certain that soap is easily decomposed when the same amount is melted, but soap is difficult to foam, it will be used a lot. In other words, it is often used in a lot of dissolved in water.
3-3) Soap and environment
Molecular structure of soap generally has a molecular structure in which a part soluble in water and a part soluble in oil adhere to each other as shown in the figure. There is sodium in the water-soluble part. Oil and friends are originally derived from oil and have a structure of about 12 to 20 carbons in a row. Longer carbons are good friends with oils, and if they are short, they become more soluble in water. The detergency of soap is built on these balances.
For soap and detergents, it is most important to reduce the amount used as much as possible.
3-4) Soap and water
In order to reduce the amount of soap used, the point to think is on the side of the water. There are water that is easy to foam using soap or water that is not foamable. They are trace minerals in water, that is, the amount of magnesium and calcium in the water varies from country to country. It is called hardness of water.
The figure shows mineral water arranged in order of soft water to hard water. The water in Japan is soft water. Water in Europe, especially the Alps, is hard water.
3-5) Hard water
Soap is easy to dissolve in water, so foams have detergency. However, magnesium and
When calcium is high, soap and soap combine to form soap scum and metal soap that do not foam. These will reduce the feeling of use of soap. Also foaming falls, so the amount used will increase. It is a chelating agent that prevents it. A chelating agent called EDTA (edetic acid) is the representative. Chelate means scissors in the crab and it works to catch magnesium and calcium inside the chelating agent as shown in the figure. Thanks to that, soap lather is greatly improved. I think that it is good to limit the use to very small amounts.
3-6) Hard water in Europe
In the hard water of Europe, it is often that the same soap as in Japan has poor foaming and can not be used. In Japan, solid soap containing sodium is common, but liquid soap containing potassium instead of sodium is common in Europe. Potassium liquid soap is used in washing places of public toilets, etc. in a melon-like round container etc even in Japan. If that liquid soap, you can remove dirt with hard water.
4) Summary
To summarize so far the story of the soap and the environment, soap is not good for river environment either synthetic or natural. It is important to wash with a small amount of soap. And I think that it is important to consider the environment of the production process.
4-1) Environmentally-friendly fats and oils
Given the conditions of good oil for use in soap, you will find that there are conditions such as being mass cheaply available, being gentle to the skin, easy to biodegrade. What is oil and grease good for the environment and health? It seems that the production amount of animal and vegetable oils and fats in the present world is less than 80 million tons. Soybeans and palm account for 50% of them. They are mainly used for food. It is also used for industrial use.
理工学、経済、実験、電池に関するコラムニスト。