The word polymer is derived from the Greek word (poly) meaning several and (mer) meaning unit or part. Polymers are also mistakenly called resin, elastomer and plastic. While plastic is only an adjective that is used for things that have the ability to change shape due to pressure, and it is often mistakenly used as a main word for plastic industries and its products.
About 60 very important polymers have been marketed so far, and their derivatives reach more than 2000 and are still increasing. Polyolefins are soft heat polymers with almost similar properties and close formulations, whose famous types are polyethylene, polypropylene, and polybutylene, which are more widely used in the pipe industry. By looking at the table below, you will notice that in terms of expansion, resistance to solvents, tensile strength, compression strength, and heat resistance and gas permeability, polypropylene has more points than polyethylene and due to heat resistance and tensile strength, polypropylene is better than poly. Butylenes are better. These items are among the most important items that are desired in the hot and cold water piping industry and cause the advantage of polypropylenes. Of course, in the meantime, pipes with a combination of polymer and aluminum were also produced, which were not well received due to the high cost and heat loss, etc. due to the presence of metal in them.
What is polyethylene? Polyethylene is one of the types of thermoplastic polymers, which means that this material turns into a liquid state when it reaches its melting point and turns into a solid state when it reaches its freezing point. Polyethylene is a chemical synthesis of ethylene, which usually comes from the combination of crude oil and natural gas. Some of its informal names are polythene or polyethylyne, in addition, it is also called PE for short. Polyethylene is mostly used to make plastic compounds so that it can be used in pure form. Although this material is used in a wide range of different uses.
What is HDPE or heavy polyethylene?
This polyethylene has an unbranched polymer chain. Therefore, the intermolecular force in the upper chain and its tensile strength are higher than other polyethylenes. The reaction conditions and the type of catalyst used in HDPE heavy polyethylene production are effective. Polymerization method with Ziegler-Natta catalyst is usually used to produce unbranched polyethylene. Heavy polyethylene is used to produce polyethylene pipes for applications under pressure
What is LDPE or light polyethylene?
This polyethylene has a branched chain. Therefore, LDPE chains cannot connect well with each other and it has weak intermolecular force and less tensile strength. This type of polyethylene is usually produced by radical polymerization. One of the characteristics of this polymer is its flexibility and the possibility of decomposition by micro-organisms. In order to produce polyethylene pipes for irrigation and small sizes, some manufacturers use this type of material, which is not recommended
What is LLDPE or linear low density polyethylene?
This polyethylene is a linear polymer with a number of short branches and is usually formed from the copolymerization of ethylene with long-chain alkenes.
MDPE or polyethylene is medium density and MDPE is usually used in the production of plastic pipes and pipe fittings. Some manufacturers use this type of material to produce polyethylene pipes for gas supply purposes