Misconceptions of Polyisoprene

People often think “natural” means safe and “synthetic” somehow means dangerous – but that’s not always the case. After all, both arsenic and mercury occur naturally and can be quite deadly while man-made vaccines save countless lives.

This kind of misconception has haunted polyisoprene for a long time.

What is polyisoprene? It’s a man-made polymer that mimics many of the qualities of natural rubber made from rubber trees. At KEP, we use synthetic polyisoprene as an alternative compound for many dip-molded products, and we hear a lot of questions about it, like:

  • Is polyisoprene safe?
  • Are polyisoprene and natural rubber the same thing?
  • Is polyisoprene as durable as other materials?
  • What are the best uses of polyisoprene?

To help you decide which material is the best choice for your project, we put our six decades of experience to work debunking some myths and misconceptions about polyisoprene.

Myth v Fact: Common Misconceptions About Polyisoprene

KEP has been working in Kent, Ohio with natural rubber latex and high-quality synthetic compounds since 1960. We’ve seen a lot of changes in the industry over the years – and we’re proud to say we’ve embraced transparency and education all along the way. We’re often surprised by the things people believe about polymers, so we love an opportunity to clear the air.

Here are the facts behind some of the most common myths we hear concerning polyisoprene vs. natural rubber latex:

Myth #1: Polyisoprene Isn’t as Safe as Natural Rubber Latex.

This idea may stem from the raw material for polyisoprene that is derived from petroleum. There is a strong association between petroleum and vehicle fuels for many people, which may make petroleum seem like a toxic substance.

Fact: Polyisoprene Is FDA Food-Grade Safe and Latex Free.

Polyisoprene is 100% latex-free – putting it on the winning side of the polyisoprene vs. latex rubber argument for anyone with a latex allergy. Plus, it meets FDA requirements for many food contact applications, and passes USP Class VI testing for medical applications. This absence of allergens means polyisoprene is safe and often preferred for use in medical and surgical settings, as well as in many food or beverage serving mechanisms. You’ll even find lots of baby products made from polyisoprene because of its safe, non-allergenic properties combined with the durability to stand up to constant torture by a teething infant.

Myth #2: Polyisoprene Wears Out Quickly.

It’s true that in situations where the very highest tensile strength – aka stretchiness without breaking – and tear resistance are crucial, natural rubber may be a better choice. That is, so long as latex allergies aren’t a concern.

Fact: Polyisoprene Is Strong, Durable and Weather-Resistant.

Polyisoprene’s uses and applications are wide-ranging thanks to its high tensile strength and good elasticity. It is resistant to physical degradation like tears, abrasions and flex fatigue. It also exhibits good resistance to inorganic compounds – such as water, salt and hydrochloric acid. Polyisoprene is also an excellent alternative to natural rubber for outdoor applications because it can better withstand most weather conditions including very low temperatures.

Myth #3: Polyisoprene Is Too Expensive.

The perception may be that natural rubber latex costs less than synthetics because it requires less processing. However, the development of synthetic polyisoprene accelerated due to the difficulty and expense of obtaining natural rubber over the decades. Attempts to synthesize an alternative go back as far as the 1880s, but ramped up considerably during World War II when demand for rubber spiked. The Allies were cut off from 90% of their natural rubber supply, which came from tropical climates, and efforts to grow rubber trees in more northern places failed. A rubber shortage ensued, and not even the most aggressive campaigns to conserve and reduce rubber consumption solved it. Finally, in 1955, the Goodyear Tire & Rubber Company developed a synthetic polyisoprene that matched the properties of natural rubber – alleviating our dependence on a resource from the other side of the world.

Fact: Polyisoprene Is a Competitively Priced Rubber Alternative.

Synthetic polyisoprene has a homogeneous polymer structure, making its processing easier and simpler than natural alternatives. That leads to more efficient manufacturing and quality control – which ultimately results in lower product manufacturing costs. Plus, it eliminates the need to ship natural rubber materials from Southeast Asia, the natural habitat of rubber trees. The widespread use of polyisoprene across many industries illustrates that it is a highly cost-effective material compared to rubber.

How KEP and Polyisoprene Can Work For You

Ready to put KEP and polyisoprene to work in your innovative dip-molded parts and prototypes? Need more info on why KEP is the best choice to meet your exacting standards? We get it. You’ve been put on hold or brushed off too often to trust that we’re different. But we love a challenge! So call us – you’ll get a real person. Tell us about your project – we’ll help you make it happen with on-time, on-budget solutions.