High Density Polyethylene

Introduction

High-density polyethylene would be a thermoplastic polymer. The monomer unit is ethylene. High-density polyethylene is also known as PEHD (Polyethylene High Density), polythene alkathene, and polythene. When a plastic substance has the Resin Identification Code (RIC-2) symbol, it is manufactured of HDPE. It is commonly abbreviated as RIC-2. Later, HDPE might have been recognized as an essential raw material within the manufacture of a wide range of products. It contributes to even more than 34 percent of the worldwide plastic industry. You've undoubtedly seen doctors wearing special disposable attire when treating a corona patient. You'll be amazed to hear that high-density polyethylene seems to be a big element of such special disposable outfits.

What is High-Density Polyethylene?

HDPE is indeed a petroleum-based thermoplastic polymer. This is a polymer composed of a large no. of repetitive units (called monomers), and thus its molecular formula would be (C₂ H₄)_n. HDPE has quite a relatively solid structure with little branching, which increases its tensile strength as well as promotes tremendous intermolecular interactions. In 1953, Karl Ziegler invented high-density polyethylene. Karl Ziegler also received the Nobel Prize in Chemistry, in 1963. This is indeed a versatile plastic with several applications ranging from pipes to storage bottles.

Production of High-Density Polyethylene

High-Density Polyethylene has been synthesized by the gas phase polymerization of ethylene. Within certain conditions, petroleum undergoes a 'cracking' mechanism. Ethylene gas would be developed as a product. Such ethylene units are now synthesized to produce HDPE. Following that, it passes through the separation as well as a drying process.

It may also be generated by catalytic procedures such as Cr-Si catalysis and Ziegler-Natta catalysis.

What are the Properties of High-Density Polyethylene?

• It can be moulded repeatedly. As an outcome, it is referred to as a thermoplastic polymer.

• It is distinguished by a high strength-to-density proportion.

• Its density is 940 kg/m₃.

• HDPE structure does not contain a large number of branching.

• It seems to have a melting point of 130.8° Celsius.

• It would be more transparent as well as more durable than low-density polyethylene.

• It is resistant to a vast array of solvents.

• HDPE crystallizes at 111.9°C.

• The specific heat capacity ranges from 1330 to 2400 J/kg K.

• This material has a latent heat of fusion of 178.6 kJ/kg.

• It displays both chemical and electrical resistance.

What are the Uses of High-Density Polyethylene?

• It is used to make discarded clothing for a range of purposes.

• It may be used to construct pipes both for potable as well as sewage water.

• Their fibres may be knotted to form a rope.

• It is being used as a house covering to preserve buildings.

• HDPE seems to be a kind of plastic typically seen in postal envelopes.

• It can be used to produce objects like chairs, ice cube trays, as well as bottles.

• HDPE should be included in a broad array of toys as well as playground items.

• It may be seen on doormats.

• It can be used in building since it is a strong as well as long-lasting material.

• HDPE is used to make cutting boards.

• HDPE film is used in food wrapping.

• HDPE is often used in wood-plastic composites.

• It is used in three-dimensional printing filaments.

• It is used in plastic surgery, notably in rhinoplasty as well as facelift treatments.

• Food, as well as beverage vessels, are made of high-density polyethylene.

Difference Between High-Density Polyethylene and Low-Density Polyethylene

High-Density Polyethylene	Low-Density Polyethylene
It has a little higher density than low-density polyethylene.	It has less density than high-density polyethylene.
It has a high strength-density ratio.	It has a poor strength-density ratio.
It is highly resistant to lower temps.	It could not effectively withstand lower temps.
It has fewer branches.	It has more branches.
It possesses higher intermolecular forces and tensile strength.	Tensile strength, as well as intermolecular forces, are lower.
It is more transparent as well as stiffer.	It is more translucent as well as softer.
It exhibits very little flexibility.	It exhibits additional flexibility.
It is not very resistant.	It has an enhanced resistant attribute.
HDPE doesn't often lose strength when exposed to light as well as oxygen.	HDPE loses strength when exposed to light as well as oxygen.
It has the resin identifying code 2.	It has the resin identifying code 4.

Conclusion

HDPE is indeed a petroleum thermoplastic that would be the most widely utilized of such 3 polyethylenes for a variety of purposes. Plastic containers, milk jars, shower bottles, as well as pipework are all examples. High-density polyethylene plastic seems to have an excellent resistance as well as melting temperature and has been famed for its excellent tensile strength with huge resilience proportion. HDPE has a lower probability of branching and is made up of tightly packed linear molecules. The occurrence of a strong intermolecular force results in the formation of a dense, intensely crystalline material.

FAQs

1. Is HDPE better as compared to PVC?

PVC is indeed a long-lasting vinyl polymer, while HDPE seems to be a petroleum-based polyethylene thermoplastic. Both pipes seem to be resistant to high temperatures. While evaluating the probability of failure when revealed to factors such as heat, rain, wind, and cold.

2. Is HDPE waterproof?

Yes, HDPE seems to be suitable for waterproofing construction bases. This can serve to prevent the structure from root incursion in contrast to waterproofing.

3. What are the risks associated with polyethylene?

Interaction with tiny clouds of dust as well as hot gases in the workplace during polyethylene production can start causing eye, skin, as well as respiratory tract irritation. Proximity to hot, molten material can result in serious burn wounds, lifelong disability, and vision problems.

4. What is the distinction between HDPE and PE?

HDPE is indeed a non-polar, extremely crystalline thermoplastic polymer. The basic HDPE has a milky-white colour, as well as the thinnest part is transparent to some level. Polyethylene is the most common type of plastic. Plastic bags, as well as cling film, are both made of Polyethylene.

5. Why is HDPE more easily recycled?

Since HDPE seems to be non-biodegradable and thus could require millennia to degrade, such bags, as well as bottles, must be easily recycled. There are several advantages to recycling HDPE. For instance, manufacturing an item from recycled HDPE becomes less expensive than manufacturing 'virgin' plastic.

6. How long can HDPE plastic be stored?

Linear extrapolation from such a standard SSDR for HDPE within the aquatic environment yields predicted half-lives varying from 58-1200 years.

7. Is HDPE permeable to water?

HDPE is indeed an excellent water vapour insulation. Because of the polymer's non-polar hydrophobicity, water possesses low solubility in HDPE, but also its coefficient of permeability would be relatively low than those in other polymers.