Have you ever wondered why plastic containers are most commonly used for storing chemicals? It goes well beyond the variety of shapes and sizes they come in, or the environmental benefits they offer, although these are major bonuses. Storing a chemical in the right container is the first way to ensure safety when handling strong acids and bases. A material that is likely to react with the chemical it holds, like a metal container, or break easily when dropped, like a glass container, isn’t going to be suitable for a substance like nitric acid, for example. This why there are a variety of plastic materials used for storing acids and bases so that each container can accommodate the unique properties of individual chemicals
Three Types of Plastic Containers
Polyethylene (PE)
Polyethylene was first synthesised in Germany in 1898 when chemist Hans von Pechmann prepared it by complete accident. Since then, PE has become the most common and widely produced plastic in the world. It can be used in three forms, which demonstrate its versatility and ability to be incorporated into a wide range of applications.
LDPE (Low-Density Polyethylene) is used to produce grocery bags. HDPE (High-Density Polyethylene) has a higher crystalline structure and can be recognised in your garbage bins and drainpipes. Ultrahigh Molecular Weight PE has higher performance applications and is even used to produce bulletproof vests. With this in mind, it’s easy to see why PE is an ideal material to store chemicals in. High-Density Polyethylene creates corrosion resistant plastic containers, and its thermoplastic properties mean that it can withstand temperatures, be cooled, and reheated again without any significant degradation. The diversity of PE variants means that it is compatible with most strong acids and bases. Like with the bulletproof vests, PE is noted for its high impact strength. This makes it perfect for storing chemicals as it is very difficult to break, and therefore decreases the risk of chemical spills.
Polymethylpentene (PMP)
PMP is a transparent, thermoplastic polymer with high chemical resistance. But this complex polyolefin is actually the backbone to a very familiar object: beakers. We’ve all used beakers in Science class, and have at some time or another dropped one on the floor. Often, they do not break, and this is because classrooms have made the shift from glass beakers to Polymethylpentene beakers While PMP is more brittle than its cousin, Polyethylene, it can be designed to be shatterproof. Its clear material means that substances can be seen easily, and it’s also highly resistant to corrosion. PMP makes perfect plastic containers for storing both acids and bases of different strengths.
Teflon
Another accidental discovery by Roy Plunkett in 1938, Polytetrafluoroethylene (PTFE) is the fluoropolymer behind Teflon. It is characterised by its hydrophobic properties, which means that most substances are unable to stick to Teflon. This is why it is able to resist corrosion from many chemicals, such as sulphuric acid and nitric acid. The slippery material means that PTFE will not absorb the chemicals it comes into contact with, and the strength of its carbon-fluorine bonds makes it non-reactive. For these reasons, Teflon-coated plastic containers are ideal for storing a wide variety of acids and bases.
But what about glass containers?
While glass containers do have their advantages, such as being nonporous and chemically inert, they have major drawbacks in the fact that they break easily. Not only would this create sharp glass fragments, it would also expose potentially harmful and corrosive chemicals. In addition, not all acids and bases are safe to store in glass containers, meaning that its versatility is very limited. Hydrofluoric acid, for example, has the propensity to eat through glass (SiO2); it contains the element Fluorine which can dislodge oxygen from its bond. On the other hand, Hydrofluoric acid can be stored in Polyethylene, Polymethylpentene, and Teflon containers, showing how plastic containers are the ideal material for containing chemicals.
The chemical substances are stored in containers made of different materials, such as plastics, metals, and glass depending on the substance. Most of the chemicals are stored in glass containers, not in plastics containers because glass is more neutral and durable in contact with chemicals. They may influence the chemicals less. Plastic materials usually contain some amounts of additives (stabilizers, processing aids, etc.) that may contaminate the chemical. Plastic containers are also used to temporarily store some of the chemicals.
Click here to find more plastic bottle for chemicals products here.
