Science | Although drinking water is good, will you choose a plastic cup?
Plastics can be seen everywhere in our real life. For example, we commonly include plastic bags, plastic wraps, plastic bowls, etc., and plastic ingredients gathered in furniture, clothing, shoes, television and radio products. Plastic starts to replace other types of materials such as wood, glass and fabrics. So why is plastic so well -sold in our society?
1. The development of plastic
In fact, all plastic stems from a small thing, it is not even made of plastic -billiards. For centuries, billiards have been made of ivory, but over -hunting in the 19th century has led to a decrease in the number of elephants, and billiard manufacturers have begun to find replacement to obtain greater benefits. Therefore, as early as 1863, a name was named. The Americans called John Wesley Hyatt accepted this challenge. In the next five years, he invented a new material called “Celluloid”. However, he also quickly found that “Celluroid” could not be used as raw materials for billiard substitutes. This material was not heavy enough, and the rebellious was not very good.
But it can color and add patterns to imitate expensive materials, such as: coral, 玳瑁, amber, and pearl mother, which creates the first plastic. The word “plastic” can be used to describe any material composed of polymers. The polymer is a macromolecular composed of the same duplicate subtype. When people mention plastic, they refer to synthetic materials. The commonality of these materials is that they were very soft, ductantly, and can be shaped into specific shapes.
Figure 1. Plastic development line (derive from the Internet)
However, although “Celluloid” is considered the first plastic produced by the official, it is flammable, which makes it risk in the production process. Therefore, the inventor began to look for alternatives. In 1907, a chemist combined the coal taron phenol and formaldehyde together to create a durable polymer called “Bakelite” . “Bakelite” is not flammable than “Celluloid”, and it is easier to make its raw materials. However, “Bakelite” is only the beginning. Sponge plastic. No later, polystyrene, also known as ethylene, is also known as ethylene. It is both flexible and patient. Micharic glass is used to use acrylic acid. After the 1930s, nylon occupied the central position. It was a polymer that imitated silk, but the intensity was several times that of silk. Since 1933, polyethylene has become one of the most widely used plastics, and it has been made into a variety of items, such as the water cups we mentioned today.
Water cups are the main things that people cannot lack in life. We use plastic cups to be attracted by the strong nature of “plastic”. They are flexible and patient, convenient and low in cost. But what kind of plastic water to drink is sanitary and safe? Although the water cup is the most common daily necessities, the more ordinary things will cause us to ignore the safety. Choosing a cup is not a simple matter, because it will be related to your life. At this stage, there are all kinds of very beautiful plastic cups in the market, but do you know if your plastic cup has reached food safety level? When we drink hot water, do our plastic cups release toxic substances? This article will provide some suggestions for you to choose a plastic cup.
Figure 2. Various cups (derive from the Internet)
2. Classification of plastic water cup materials
For the material of the water cups we use for us, we can open the bottom of each plastic container. Generally, there will be a numeric triangle symbol logo. And the logo, this logo also allows us to know what the plastic is used and use it under the environment. Let’s learn them together!
Figure 3. Material label (derive from the Internet)
No. 1 PET material: Polyzhe acidic acid, the original use is as artificial fibers, tapes, etc., only for mineral water bottle in 1976;
No. 2 HDPE material: Also known as high -density polyethylene, shower gel, shampoo bottle are all such materials, most of these materials are opaque to feel wax;
No. 3 PVC material: polyvinyl chloride, mostly used to make water pipes, raincoats, schoolbags, building materials, etc.
LDPE No. 4: Low -density polyethylene is a plastic wrap, plastic bag that we can see everywhere;
No. 5 PP material: scientific name polypropylene, often used as a pacifier material for baby bottle or the material of the current best -selling microwave oven heating box;
No. 6 PS material: polystyrene, which is often used in toys, stationery, instant noodle boxes, disposable tableware, etc.;
PC materials in other species No. 7: polycarbonate, used to make bottle, space cup, etc., but they are argued because they are rich in bisphenol A.
Tritan material: It is a water cup made of Tritan. Tritan is directly translated with concentration fiber, which has hygiene, environmental protection, safety, heat resistance, and durability, so it is also used on baby supplies.
Third, the scientific basis for selection of plastic water cups
The plastic cup is dazzling in the mall, which is dazzling, so you need to provide some reference basis for this article. We first need to see what material it is, search for its glass conversion temperature. What is glass conversion temperature?
First of all, plastic belongs to amorphous polymer. It has three mechanical states. They are glass, high -elastic and adhesive. When the temperature is low, the material is similar to the glass shape and the glass, and this state is the glass state; when the temperature continues to rise to a certain range, the deformation of the material increases significantly, and the subsequent temperature interval is relatively stable. This state is a high -elastic state, the temperature continues to rise and gradually increases, and the material gradually becomes a sticky fluid. At this time, the shape cannot be recovered. This state is a sticky state. We usually change the transformation between the glass and the high elastic state.
Why look at the temperature of the glass? Because the glass transformation temperature is the upper limit temperature used by non -crystalline thermoplastic plastic, which is the lower limit temperature used by rubber. We must use within the range of this temperature, or we will produce toxic substances during the deformation process. The reference data can be shown in Figure 3.
Figure 4. The material selection basis 1
You also need to look at thermal deformation temperature. If we want to hold hot water, we must pay attention to thermal deformation temperature. The thermal deformation temperature is a parameter that expresses the relationship between heating and deformation of the measured object. It is a amount of measuring the heating resistance of polymers or polymer materials . It is also necessary to pay attention to its transparency, but this is not a necessary condition. Some friends like the material with high transparency, and some are the opposite. They choose according to their preferences. Figure 4 below provides plastic materials for everyone to choose from.
Figure 5. The material selection basis 2
Fourth, the difference between different materials plastic
(1) Products commonly used in different materials in life
Figure 6. Common items of plastic material life (derive from the Internet)
(2) From the perspective of thermal deformation temperature
The thermal deformation temperature of PC, Tritan, and PP is ranked among the top three. Among them, PC has super high and low temperature capabilities. The material of PC itself is non -toxic. It is possible to release bisphenol A (BPA) toxic and easily cause cancer.
Bisphenol A (BPA): Scientific name 2,2-two (4-hydroxyl phenyl) propine, referred to as diopenol-based propane. White crystal, melting point 156 ~ 158 ℃. It is an important organic chemical raw material. The industrial bisphenol A series is made of phenol and acetone in an acidic medium. According to the data, bisphenol A is a low toxic chemical, and the official website of the Ministry of Health was announced on April 20, 2011 that the Ministry of Health was soliciting opinions on the “Prohibition of Bisphenol A for the Announcement of Food container for infants and young children”. Since June 1, 2011, the production of polycarbonate infant bottles and other infant A bottle with bisphenol A.
Compared with PC materials, PP materials are safer and further into the vision of the masses. It is currently the only plastic shell that can be placed in a microwave oven, which is a semi -crystalline thermoplastic plastic. It has high impact resistance, strong mechanical properties, anti -various organic solvents and acid -base corrosion, and Australian coins are also made of polypropylene. However, PP’s transparency is very poor, only about 65.7%, which is lacking in a beautiful perspective when making cups.
Let’s look at Tritan materials again. Tritan translates directly as a cluster fiber. It is a new generation of materials developed by the U.S. Eastman Group, and has obtained JHOSPA food -grade certification. Its thermal deformation temperature is also very high, high -temperature resistant, and does not contain bisphenol A (BPA). It has good impact resistance, good resistance, hydrolysis, and easy to form. It can also be said that it can replace PC s material.
(3) From the perspective of transparency
PET, PVC, PS, PC, Tritan’s transparency is more than 80%. However, in terms of PET materials, its thermal deformation temperature is only 70 ° C, so cups using this material are not easy to load hot water. Although it is oil -resistant, fat, thinner, dilute, and dilute, and most solvents, PET plastic may release harmful substances after 10 months of use.
DEHP: It is a type of phthalate, which is made of glycol or vascol (2-EH) and phtharaic acid, so it is called DEHP. It is usually used as a plasticizer. The DEHP effect of the plasticizer is similar to artificial hormones. Long -term accumulation of high doses in the body may cause children to chaos gender and endanger male reproductive ability. Although it cannot be proved to be carcinogenic to humans, it can cause carcinogenic reactions to animals.
Looking at the PVC materials, most of them are used to make water pipes, raincoats, schoolbags, building materials, etc., which are cheap for excellent plasticity, but it is easy to decompose when high temperature water and oil and fat. PVC materials also contain stabilizers, lubricants, tough agents, plasticizers and other additives in addition to the PVC resin in the formula. The heating and decomposition will definitely produce hydrogen chloride gas. It is dissolved in water and is hydrochloride. Big, at the same time, it will release the two evil heroes, which are poisonous.
Two Evil: that is, 1,4-epoxy miscellaneous rings, which is a single ring organic compound. Such substances are very stable, high melting point, extremely difficult to dissolve in water, and can be dissolved in most organic solvents. The tasteless fat -soluble substance, so it is very easy to accumulate in the organism, which is harmful to the human body. Two evils are the representative of environmental endocrine interference. They can interfere with the endocrine of the body. Evil British can cause female animal ovarian dysfunction, inhibit the effect of estrogen, and make female animals infertility, decreased fetal nibi, and abortion. It has obvious immune toxicity, which can cause animal thymus atrophy, cellular immune and body fluid immune function.
PS material: polystyrene, which is often used in toys, stationery, instant noodle boxes, disposable tableware, etc., which are both heat -resistant and cold, but do not put it in a microwave, because high temperatures are easy to break down benzene substances. Do not use it to put strong acids (such as orange juice) and strong alkali, because it is easy to dissolve polystyrene that is not good for the body. It must be paid special attention to some microwave lunch boxes. The box body is made of 05 PP, but the lid is made of 06 PS (polystyrene), but it is not heat -resistant. Put in the microwave oven together.
Comprehensive analysis, we should pay attention to two points when choosing a plastic cup. First: Whether it is resistant to high temperature, will be toxic substances when holding hot water. Second: Whether hygiene, environmental protection, recycled use, whether to meet the national food safety use standards. Now that Yan Tian is here, people’s drinking water is doubled. What cup do you use to drink water? If it is wrong, you may damage your physical and mental health, then will you choose a cup now?
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