Polyurethane vs. Polyethylene: What’s the Difference?

Polyurethane (PU) and polyethylene (PE) are both plastics suitable as material for tubes or piping. However, PU and PE have different compositions and structures, which means they suit different purposes. If you are looking to use plastic piping in a project or design, it can be hard to determine what material is the best fit.

As a leading plastic pipe company in the UAE, we have plenty of experience with these two plastics. At Polyfab, we supply polyethylene pipes and many other plastics, and can share our expertise with you if you are looking to understand polyurethane vs polyethylene.

Learn more here about the difference between polyurethane and polyethylene and get the answers to common plastics FAQs so that you can make a confident choice.

Polyurethane & Polyethylene: What Are They and What Are They Used For?

Polyurethane (PU)

Polyurethane (PU) is made by combining the compounds diisocyanates (TDI and MDI) and polyols. The reaction between these compounds creates a crystalline compound with urethane linkages.

PU is a widely used plastic. Its flexibility and resilience make it suitable for a wide range of applications, including insulation, cushioning, and coatings. Polyurethane can be custom-made to be soft and stretchy or more rigid.

For tubing, hosing, and other pneumatic applications, polyurethane is very useful. It’s resilient against heat plus chemicals, gases, and most fuels, oils, or greases, and so is well suited to industrial applications.

Polyethylene (PE)

Polyethylene (PE) is the most commonly used plastic in the world. Polyethylene is created by processing ethylene, breaking down carbon bonds and converting them into a polymer.

Of the four categories of PE, two are most prominent:

• Low-density polyethylene (LDPE)
• High-density polyethylene (HDPE)

LDPE is often used in tubing because it is chemical-resistant. It is suited for making products like plastic bottles for drinks, bags and molded lab equipment.

HDPE is ideal for heavier-duty uses like industrial and domestic piping. HDPE pipes are also highly chemical-resistant and it is strong enough to be used to make toys, prosthetics, outdoor furniture and bottles for detergents and cleaning products.

Polyurethane Vs Polyethylene: Core Differences

What’s the difference between polyurethane and polyethylene? Below are five core differences:

1. Hardness

Polyethylene offers limited durometers. For example, HDPE is always rigid. The density of the polyethylene chain determines its rigidity. Therefore, LDPE is more flexible.

Polyurethane, however, has a wider range of durometers from soft foam through to very hard.

2. Forms

Polyethylene is available as solid or foam only. Polyurethane is formulated to design and product needs.

3. Recycling

Manufacturers can melt, reform, and recycle PE easily because it is a thermoplastic. PU cannot be recycled.

4. Heat Resistance

PE is heat-resistant up to around 150°F or 65°C. PU is heat-resistant up to around 300°F or 150°C.

5. Bonding

Polyethylene is difficult to bond to other subcomponents. Polyurethane, on the other hand, bonds well to a variety of materials and is often combined with PVC.

Which Is Better: Polyurethane or Polyethylene?

The answer to this question depends on your intended application. Here’s a summary of their relative advantages:

PU is:

• More UV-resistant
• Less flammable
• Electrical-resistant
• More flexible
• More heat-resistant

PE is:

• More chemical-resistant
• Lightweight
• Lower-cost

In terms of rigid piping, polyethylene is best. This is because it is lightweight, chemical resistant and very durable.

Polyurethane Vs. Polyethylene Vs Other Plastics: FAQs Answered

Which Is Better: Polypropylene or Polyethylene?

Polypropylene (PPR) is another widely used thermoplastic. It is more rigid than polyethylene. One form of polypropylene, PPR, is well suited as a material for hot and cold water pipes due to the plastic being more hygienic and heat-resistant to higher temperatures than PE. However, PPR may not have the flexibility you need for your project, in which case PE would be better.

Which Is Stronger: Polyurethane or Polypropylene?

While both are strong, polyurethanes usually offer more robust physical properties, especially in extreme environments.

What Is the Difference Between Polyurethane and Polyethylene Sealant?

Sealant refers to the adhesives designed to bond plastics together. You need to use a specialist sealant for both PU and PE to ensure a good bond. Sealants designed for one plastic are not likely to bond well on another type of plastic.

Which Is Better: Polyethylene or Polyvinylchloride?

Polyvinylchloride (PVC) is another plastic with a wide range of applications. It can take a rigid or softer and more flexible form. PVC pipes are well suited to outdoor environments and are therefore often used as a cost-effective solution for plumbing, drainage, irrigation, and water distribution. However, PE can better withstand the highest temperatures and harshest conditions.

Which Is Better: Polyurethane or Polyvinylchloride?

PU has better flexibility than PVC and is more resistant to damage. However, PVC offers an excellent solution where ease of use and cost-effectiveness are important. PVC  is lightweight and easy to cut, plus it withstands environmental degradation.

Making the Right Choice

Both PU and PE are excellent materials. You need to consider the unique needs of your project to determine which is the right one to use.

For bespoke advice on PU or PE, or PVC, contact us. We can help you choose the right plastic piping.