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V International Student Research and Creative Competition Start in Science

The co-author of this article is Meredith Juncker. Meredith Junker is a graduate student working on her PhD in biochemistry and molecular biology at the University of Louisiana Medical Center. Her research focuses on proteins and neurodegenerative diseases.

The number of sources used in this article is 13. You will find a list of them at the bottom of the page.

If you want to show your students or children a fun and safe experiment, which can then be easily removed and which allows you to show a truly impressive result, then you came to the address. Using a small amount of milk and vinegar, you can create a plastic-like material in minutes. This experiment is absolutely safe, and the resulting plastic can be put into any business.

The author of the work was awarded a diploma of the winner of the I degree

INTRODUCTION

All people use items made of plastic. Over the years, new types of plastics have been invented that have different properties. Nowadays, synthetic plastic is produced at enterprises using oil refining. I learned that since ancient times, people used casein-based plastic. This protein plastic is called halalite. Buttons, handles for cutlery, combs and much more were made from it. I was interested in the manufacturing process of such plastic. I found out that anyone can cook milk plastic at home.

Relevance of the selected topic: Milk plastic has good qualities: it is easy to make, it does not cause allergies, it can decompose and is not electrified.

Goal: obtaining, manufacturing and researching the properties of milk plastic products.

Object of study: milk.

Subject of study: the process of turning milk into plastic.

Hypothesis: milk can turn into plastic at home.

Research Method: questioning, experiment.

Tasks:

a) expand knowledge of the properties of milk and halite,

b) collect and study information on milk plastic from additional sources,

c) conduct an experiment to turn milk into plastic at home (use various types of milk and acid),

d) develop instructions "How to get natural plastic from milk at home?"

e) to conduct a survey among students in grades 2 A and 4 B, in order to find out how much they know about milk, its properties and how to turn milk into plastic.

  1. THEORETICAL PART
    • Milk is an ordinary miracle

On the globe, there are more than 6,000 mammals that feed their young with milk [7, p. 117]. In addition to the cows and goats known to us, these are also horses, camels, cats, whales, hares, hedgehogs. Their milk is different in taste, fat content and in the composition of the substances that enter it. But everyone has it white. White color gives milk milk protein. About 110 grams of solid nutrients are found in every liter of milk. These are fatty oil, casein, milk sugar and minerals.

Cow's milkPerhaps one of the most important products for the inhabitants of Europe. It is satisfying: a liter of milk in its nutrition is equal to 500 g of beef, while milk protein is better absorbed than protein of meat or fish. Cow's milk has everything that is needed for the body - proteins, fats, carbohydrates, mineral salts, vitamins, enzymes, trace elements.

In goat milk more vitamins and minerals than in cow's milk. With a fat content of 4%, it is absorbed almost completely. It is recommended to drink it with joint diseases, asthma, insomnia, anemia, loss of vision, stomach diseases, diathesis. But he also has drawbacks. This is a specific smell and an unpleasant aftertaste.

Mare's milk - it is a white with a blue tint liquid, tart to the taste. Koumiss is made from this milk. Koumiss is recognized as a useful tonic. Koumiss is drunk for various diseases of the liver, lungs, and stomach.) In koumiss, there are much more vitamins and minerals than in cow. In the mid-19th century, kumis successfully treated soldiers with tuberculosis.

Camel milk (shubat) is a traditional oriental drink. (Central Asia, the Middle East, the Arab countries of the Arabian Peninsula). Camel milk is drunk there every day, cheese, ice cream, and cocoa are prepared from it. For Arabs, shubat is both food and medicine. They use shubat for diseases: asthma, tuberculosis, inflammation of the liver, diabetes, psoriasis. In the West, they rarely drink camel milk: it has a specific taste, sharp and salty, which is called "for everybody." Camel milk has three times more vitamins C and D than cow's milk, but less milk sugar - lactose.

Deer milk The peoples of the North drink. Three times more protein and 5 times more fat in cow’s milk in reindeer milk. Reindeer milk is usually diluted with water.

Buffalo milk used in India, Indonesia, Egypt, Georgia, Azerbaijan, Armenia, Italy and in the south of Russia (for example, in Dagestan, in the Kuban). Buffalo milk has a delicate taste, practically no smell. In buffalo milk there is more fat, protein, calcium, vitamins A, C and group B than in cow.

The most valuable, most useful is considered donkey milk. The ancient Romans washed their face. It was believed that such a procedure will maintain youthfulness and elasticity of the skin. And the stories tell about the rejuvenating baths of donkey milk.

When did a person begin to drink milk and prepare butter and cheese from it?

Animal milk is the fluid that forms in the mammary glands of mammalian females to feed babies after birth [6, p. 418]. Man began to eat animal milk in the 8-9th millennium BC. e., when the peoples of the Middle East domesticated sheep and goats [6, p. 251]. In the 7th millennium in the territory of modern Turkey, people began to graze cows and drink milk. The mention of milk is still in the Bible. It has many references to milk. Abel, the son of Adam, grazed sheep and probably drank milk. The Bible says in Jacob’s prediction that Judas’s teeth are white with milk. The land of Canaan was a land of milk and honey. In 1500 BC Job often referred to cheese.

At all times, people highly appreciated the healing properties of milk [4, p. 211]. They called milk "juice of life", "elixir of life."

Ancient philosophers did not know the composition and properties of milk, but saw its effect on the body and called it white blood. BC, doctors of Egypt, Ancient Rome and Greece treated with milk sick patients with consumption, gout, anemia.

The famous doctor Hippocrates believed that milk is a medicine, Avicenna argued that milk is the best food for humans, Academician Pavlov, that milk is food prepared by nature.

The most beautiful women in the world used milk to preserve their beauty and youth for many years: the Queen of Egypt Cleopatra took milk baths, and the wife of Nero Poppea took 500 donkeys with her to travel to take milk baths that improve skin. Animal milk saved people from death in the famine.

  • History of origin and properties of halalite

The discovery of the chemical treatment of cottage cheese was first mentioned in 1885 in a German patent issued by Emery Walds [3, p. 118]. However, the discovery was not put into practice. 12 years have passed until the manufacture of artificial mass from cottage cheese was used to produce white slate boards. In 1897, the question was raised in Germany about the need to make a white board for writing on it with a pencil. The publishing and lithographic company Edler and Kirsch became interested in this matter. Among the different ways to get such a board, this company has tried the use of cottage cheese. However, experiments with cottage cheese for the production of a writing board on it with a pencil failed. To solve this problem, the company invited the chemist Adolf Spitieler. He was not able to make a white board for writing, but he prepared a putty from cottage cheese, which, when dried, looked very much like a horn. The chemist Spitiler and his master, Kirsch, understood very well that they had made an important discovery, and therefore they obtained a patent that protected their invention both at home, in Germany, and abroad. After the first discovery of artificial plastic mass from cottage cheese, it took another two years of work for various improvements and improvements, before it was possible to begin the organization and construction of the plant. To build the plant, firstly, a lot of capital was required, and, secondly, the help of technicians and engineers was needed. Therefore, the inventors were forced to agree with a German rubber company manufacturing rubber products regarding the production of their plastic mass at the company's factory in Hamburg. In this case, it was possible to use the equipment used in the manufacture of rubber. In 1900, an agreement was concluded between the inventors and German and French entrepreneurs on the organization of production of the plastic mass invented by Spitter, and it was given the name “galalit”.

The name “galalit” comes from the Greek words γάλα (milk) and λιθος (stone) and in Russian means “milk stone”, but this material most resembles plastic [3, p. 116]. Buttons, combs, buckles, handles for knives, forks and razors were made from halalite. Many necessary and beautiful things could be made from galalite. Products made of halalite turned out to be very beautiful, since in the manufacture of the mass you can add various paints, gold and silver powders, as well as substances that make galalite transparent, like glass. With the help of machines, patterns were displayed on products.

In 1928, the First State Plant was founded, founded near Moscow in the village of Mnevniki (the Galalit plant).

They decided to put on production of halalite in order to free themselves from the need to buy abroad raw materials and semi-finished products going to the manufacture of various items. Another plus is that you don’t have to buy anything abroad to produce halalite. The main raw material is casein, which was prepared from cow's milk; it was in sufficient quantities in the USSR. The beauty of halalite, the simplicity of its production methods, widespread use in the country's economy and a rich raw material base stimulated the expansion of its production.

But over time, new types of synthetic plastic began to be invented, which displaced halalite from production.

  1. PRACTICAL PART

2.1. What do we know about milk and its properties?

To answer this question, I conducted a survey among students of our 2 A class. The survey was attended by 26 students. For comparison, I conducted a survey in 4 B class, in which 29 people took part (see Appendix 1).

Some guys chose several answers to questions. After the questionnaire, I concluded that students in grades 2 A and 4 B possess some information about milk and its properties, but I introduced them to more accurate facts about milk. The guys listened carefully to me, and after the report they asked questions. Most students did not know that milk can make milk plastic so easily. What happens when you add acid to milk? No one knew the answer to this question. I think that for all students the knowledge gained about milk, its properties and milk plastic will be useful.

2.2. Production and research of milk plastic at home

I spent the summer holidays in the Perm region in the village of my grandparents. I helped to take care of animals and I really liked to get cream from milk using a separator. Once, my grandmother was making cheese from home-made cottage cheese. At first he reminded me of plasticine, the same plastic. After some time, the cheese hardened. This process interested me. To find out more, I went to the library. From literature I learned how not only cottage cheese and cheese can be made from milk, but also that when acid is added, original products are obtained, such as key rings, souvenirs, magnets [2, p. 36]. I learned that since ancient times, people used casein-based plastic. This protein plastic is called halalite (formaldehyde-treated casein). I was interested in the manufacturing process of such plastic. I found out that anyone can cook milk plastic at home. Casein coagulates in milk when acid is added.

I decided to experiment with various milk and acids. Acid: vinegar 9%, citric acid (dry powder), lemon juice, calcium chloride. The fact that when calcium chloride is added to milk, one can get casein or cottage cheese from the literature [5, p. 494]. And about what else you can add lemon juice or citric acid to milk and get cottage cheese, I learned from my grandmother. In this way, she cooked me cottage cheese in the morning. Natural casein is found in cottage cheese and cheese. Thanks to him, cheese seems to us so “rubber". Casein is a complex protein, a substance that builds and repairs human muscles [1, p. 163].

I used different milk: milk with a fat content of 3.2%, skim, fat content of 2.5%, natural cow and goat milk.

First you need to prepare everything you need for the experiment:

- rubber gloves, safety glasses and a bathrobe.

- Casserole, spoon, glass, gauze, paper napkins, water-soluble dyes, gouache, paints, sparkles, sandpaper, plastic, silicone molds.

And so, we begin to investigate (Appendix 2). Gently pour 1 cup of cow's milk in a saucepan, with a fat content of 3.2%. Constantly stir the milk so as not to burn. I warm it until the bubbles go. I turn it off. No need to boil milk. I add 1 tablespoon of 9% vinegar, carefully mix the resulting mixture. Milk coagulates; it is a chemical process of acetic acid and protein in milk. I wait until it cools, so as not to get burned in contact with the saucepan. Slowly filter through cheesecloth and a sieve so that the milk that has curdled (casein) is separated from the liquid (whey). The resulting substance is like cottage cheese. Now you need to squeeze and put the mixture on a napkin, soak all the remaining liquid. I spread it in silicone or plastic molds and leave to dry. The more milk you use, the more solids you get. For each new glass of milk, you need to add an additional tablespoon of acid. After 12 hours, the mixture was soft. I made a hole, because I wanted to make a keychain. After another 12 hours, it became denser and was already drying around the edges. After 48 hours, the mixture obtained from milk turned into plastic. Now this plastic is impossible to wrinkle, it has taken its final shape. In its structure, it resembles plastic. I sanded it with sandpaper and painted it with gouache. Then I did the same with other types of milk, and replaced vinegar with citric acid, lemon juice and calcium chloride. The results of the experiments I entered in the table (Appendix 3). The best crafts were made from milk with a fat content of 3.2% and 2.5% and 9% vinegar. This means that the mixture prepared with citric acid, lemon juice and calcium chloride is not suitable for the manufacture of crafts, but it is more useful to eat it.

2.3. The study of the properties of milk plastic

I conducted a study of the properties of milk plastic and synthetic plastic (Appendix 4).

Plastic made of milk is not toxic, does not emit harmful substances and does not smell.

It can decompose, because made of milk protein - casein.

Milk plastic is not electrified. When rubbing with a synthetic bag, the hair is electrified, but if rubbed with milk plastic - no. So you can make a comb out of it.

The resulting plastic can be easily painted with gouache or paints, and it is curled up on synthetic plastic.

All these properties have the advantage of milk plastic over synthetic plastic. But due to its higher strength, synthetic plastic has supplanted natural plastic from production. If dropped, my plastic will not collapse, but when hit with a hammer - it will break. It would be possible to make it durable with the help of formaldehyde, then a real halalite would be obtained. But formaldehyde is a very dangerous and toxic agent. It is forbidden to use at home!

CONCLUSION

As a result of studying the literature, I learned about the properties of milk and made milk plastic. I conducted a survey and concluded that students in grades 2 A and 4 B have some information about milk and its properties, but I introduced them to more accurate facts about milk.

I did an experiment where conditions were created for obtaining plastic from milk. And I found out that casein, prepared with the help of citric acid, lemon juice and calcium chloride, is not suitable for making crafts, but it is more useful to eat it. And the best thing was products made from milk with a fat content of 2.5%, 3.2% and 9% vinegar. I conducted a study of the properties of milk plastic. This plastic has good qualities: it is easy to manufacture, it is non-toxic, it does not cause allergies, it does not electrify, it can be painted with gouache or dyes during manufacture and it can decompose. Я думаю этот экологически чистый продукт был бы актуальным решением проблемы загрязнения атмосферы. Так как обычная синтетическая пластмасса разлагается от 100 лет и более.

Продуктом моей работы является инструкция «Как получить натуральный пластик из молока в домашних условиях?» с выработанными мной рекомендациями (приложение 5).

Гипотеза подтвердилась – молоко может превратиться в пластик при создании определенных условий.

Я изготовил из молочного пластика брелоки для ключей, магнитики, сувениры и подарил их своим родственникам и друзьям. They can replace clay and modeling dough when you make different crafts. In the future I will continue my experiments. I plan to try with apple cider vinegar, ascorbic acid, dried, coconut, mare's milk.

Having worked on this topic, I learned that you can not only drink milk, but also make necessary, useful things out of it, and that we can replace the usual synthetic plastic with milk plastic.

LIST OF USED LITERATURE

  1. Aniashvili K.S. Illustrated book of scientific experiments and experiments without special props / K.S. Aniashvili. - M .: AST, 2015 .-- 208 p.
  2. Bolushevsky S.V. Funny scientific experiments for children and adults. Chemistry / S.V. Bolushevsky. - M .: EKSMO, 2013. -72 p.
  3. Grigoriev P.G. Technology of protein plastic masses / P.G. Grigoryev. - M.: ONTI, 1935 .-- 219 p.
  4. Kovalev V.M. Russian cuisine: traditions and customs / V.M. Kovalev, N.P. Grave. - M.: “Soviet Russia”, 1990. - 256 p.
  5. Lagutina T.V. Baby food / T.V. Lagutina. - M .: RIPOL classic, 2009 .-- 640 p.
  6. Shalaeva G.P. All about everything. Volume 1. Popular encyclopedia for children / G.P. Shalaeva, E.A. Kashinskaya. - M .: "WORD", 1993. - 512 p.
  7. Shalaeva G.P. All about everything. Volume 7. Popular encyclopedia for children / G.P. Shalaeva, E.A. Kashinskaya. - M .: "WORD", 1994. - 448 p.

Questionnaire for students of grade 2 A

  1. What kind of animal milk does a person eat?

  1. How to turn milk into plastic?

Not answered - 26 people

  1. What amazing experiments can be done with milk?

Dry - 2 people

Make plastic - 12 people

To make oil - 1 person

Get cream - 1 person

Make starch - 1 person

Make material - 1 person

Did not answer - 8 people

  1. What happens if you add acid (acetic, citric) to warm milk?

A) the color will change - 4 people

B) milk will curl - 15 people

C) nothing - 5 people

Not answered - 2 people

  1. What is the name of the mixture obtained by adding acid to milk?

A) kefir - 13 people

B) mineral - 2 people

C) casein - 8 people

Not answered - 3 people

Questionnaire for students of grade 4 B

1. What kind of animal milk does a person eat?

  1. How to turn milk into plastic?

Freeze - 1 person

Add chemicals - 1 person

Not answered - 27 people

  1. What amazing experiments can be done with milk?

To make oil - 5 people

Get cream - 3 people

Make chocolate - 2 people

Make cheese - 2 people

Cook kefir - 8 people

Make ice cream - 3 people

Dye with dyes - 1 person

Make yogurt - 1 person

Add Coca-Cola - 4 people

Draw with milk - 1 person

Add vinegar - 1 person

Add soda - 1 person

Add sunflower oil - 1 person

Did not answer - 7 people

  1. What happens if you add acid (acetic, citric) to warm milk?

A) the color will change - 2 people

B) milk will curl - 27 people

B) nothing - 0 people

  1. What is the name of the mixture obtained by adding acid to milk?

B) mineral - 3 people

C) casein - 19 people

Experiment

Table "Experimental Results"

Natural cow's milk

Cow's milk 3.2%

Cow's milk 2.5%

10.10.17g. Loose mass, enough for 2 forms. Serum separated 150 ml. Crafts are not even and greasy.

03/08/18 The mass is thick, enough for 2 forms. Serum separated 140 ml. Crafts are smooth and beautiful.

01/30/18 The mass is thick, enough for 4 forms. Serum separated 200 ml. Crafts are smooth and beautiful.

01/27/18 The mass is dry, crumbly, enough for 1 form. Serum separated 190 ml. Craft cracked

10/08/17 The mass is liquid, similar to the dough, spread on gauze, enough for 2 forms. Serum separated 150ml. Crafts are deformed, a little greasy.

10.10.17g. The mass is liquid, similar to the dough, spread on gauze, enough for 3 forms. Serum separated 150 ml. Crafts are greasy, stratified.

03/08/18 The mass is liquid, similar to the dough, spread on gauze, enough for 1 form. Serum separated 150 ml. The craft was deformed.

02/02/18 The mass is liquid, similar to the dough, spread on gauze, enough for 1 form. Serum separated 180 ml. The craft is flat, a little greasy.

01/27/18 The mass is porridge-like, enough for 2 forms. Serum separated 180 ml. Crafts are flat and dry.

10.10.17g. The mass is liquid, similar to the dough, spread on gauze, enough for 2 forms. Serum separated 150 ml. Crafts are greasy, cracked.

01/21/18 The mass is thick, enough for 3 forms. Serum separated 170 ml. Crafts are smooth but greasy.

01/14/18 The mass is thick, enough for 1 form. Serum separated 150 ml. The craft is beautiful, but oily.

01/30/18 The mass is liquid, similar to the dough, spread on gauze, enough for 2 forms. Serum separated 180 ml. Crafts are smooth but greasy.

01/30/18 The mass is thick, enough for 2 forms. Serum separated 180 ml. Crafts cracked, dry.

01/21/18 The mass is liquid, similar to the dough, spread on gauze, enough for 2 forms. Serum separated 150 ml. Crafts are deformed, greasy.

10/15/17 The mass is thick, enough for 3 forms. Serum separated 140 ml. Crafts were deformed, cracked.

10/15/17 The mass is thick, enough for 3 forms. Serum separated 150 ml. Crafts are not greasy, they are slightly deformed.

02/02/18 The mass is porridge-like, enough for 1 large form. Serum separated 200 ml. Craft oily, cracked.

01/27/18 The mass is thick, enough for 1 large form. Serum separated 150 ml. The craft cracked and crumbled.

08.21.17g. The experiment did not work, the milk did not curl.

The study of the properties of milk plastic

Instruction "How to get natural plastic from milk at home?"

  1. Conduct an experiment in the presence of adults.
  2. Use vinegar carefully, as pairs of acetic acid irritate the mucous membrane of the respiratory tract.
  3. Be careful when working on the stove.
  4. Use rubber gloves, safety glasses and a bathrobe.
  5. Prepare everything you need for the manufacture of milk plastic:

Milk with a fat content of 3.2% or 2.5% - 1 cup.

Vinegar 9% - 1 tablespoon.

Saucepan, spoon, glass, gauze, paper napkins, sieve, glass.

Molds are plastic, silicone.

Water-soluble dyes, gouache, paints, sparkles.

After everything you need is ready for the experiment and familiarized with safety precautions, you can get to work.

Gently pour 1 cup of milk into the saucepan. Stir the milk constantly so that it does not burn. Warm until bubbles go. Turn off the stove. No need to boil milk. If necessary, you can add food coloring. Add 1 tablespoon of 9% vinegar, mix thoroughly the resulting mixture. Milk coagulates; it is a chemical process of acetic acid and protein in milk.

Wait until it cools down so as not to burn yourself when it comes into contact with the saucepan. Slowly strain the mixture through cheesecloth and sieve so that the milk that has curdled (casein) is separated from the liquid (whey). The resulting substance is like cottage cheese. Now you need to squeeze and put the mixture on napkins, dry all the remaining liquid. The mixture is similar to plasticine. Put it in silicone or plastic molds and leave to dry. The more milk you use, the more solids you get. For each new glass of milk, you need to add an additional tablespoon of acid.

After 48 hours, the mixture obtained from milk turned into plastic. Now this plastic is impossible to wrinkle, it has taken its final shape. In its structure, it resembles plastic. If necessary, you can sand it with sandpaper and paint it with gouache. In such an easy way, you can make milk plastic yourself.

Plastic preparation process

Self cooking method galalite plastics even a person who does not know chemistry will perform. With the help of milk and vinegar, this product is prepared. From the plastic mass, you can create the desired shape, and outwardly it resembles moistened cheese. Usually after 10 or 15 minutes the mass is ready. It reaches a solid state in two days.

In terms of strength, the resulting product is quite good. Although it can be broken into two parts, but if it falls, it can remain intact. But if you hit hard with a hammer, then it will easily split. Self-made plastic is not suitable for serious purposes. But you can replace expensive factory plastic with it.

Galalit is prepared using milk and vinegar. The use of two cups, a plastic spoon, gauze, a stack of paper napkins is a necessary set of additional items. Also needed: aluminum foil to give the product specific shapes. A rolling pin is a sheet of flat shape. The wax paper is lined and the procedures for creating and rolling the plastic mass are done on it. It is easy to remove liquid from it and casein does not stick to it.

In a glass with milk add one teaspoon. This volume of milk is enough to make a plastic piece, which has a thickness of 3 millimeters and a diameter of 5 centimeters. Boil milk and stir constantly. Fire is reduced if it burns. Boiled milk is removed from the fire and pour vinegar. The appearance of casein particles immediately becomes apparent. Within 30 seconds, this mixture is mixed.

Strain this milk through cheesecloth, pouring into another cup. Most of the particles of casein will remain on gauze. If casein is in the sewer, then this will lead to the fact that it will have to be cleaned. Therefore, milk is poured into another cup. After squeezing the gauze, the casein mass should turn into one lump. Then it is placed on wax paper.

Napkins need to continue the extraction of water from this plastic mass. They are applied to plastic, and excess moisture is easily absorbed into them. In order to not have, in the future, difficulties with sculpting, it is necessary to spin not all the moisture; otherwise, this will lead to the drying of the plastic. A slightly moistened shapeless mass needs to be rolled out with a rolling pin to a flat state.

The finished sheet should not be brittle. Drying speed and strength will depend on the thickness of this sheet. A load is placed on it so that the plastic does not deform during the drying process. First, wax paper is put on the mass, and then pressed on top with a load. Products with complex shapes are fixed with plastic foil. It is possible to proceed to grinding and painting the mold only after the final transformation of the mass into a solid form.