The history buffs among us will remember the watershed moment in the twentieth century when manufacturing was turned on its head. Plastic had arrived, and, as a result, once formidable engineering boundaries were torn asunder and reborn as new manufacturing processes where engineers could dial in desirable properties when making products. These new breeds of plastic are now designer manufactured to fit a purpose, but where does the versatility factor begin? It’s almost tantamount to some human reflex to say plastic is highly adaptive to its targeted market, but there must be a point where this tailoring process takes hold. Let’s illustrate this move from plain old base plastic to ideal synthetics with a look at polyurethane, the benchmark material when it comes to versatility and rubber-like performance.
First of all, polyurethane is already celebrated as a material with considerably diverse mechanical properties. These characteristics have seen the polymer infiltrate all of industry as a chemical-resistant and abrasion-proof substance, one that can be easily moulded into any shape, all at a fraction of the cost it would take to manufacture a comparable metal product. Add to these features the versatility to simulate the performance of any rubber construct, thanks to the type of creative chemistry that first sparked the plastics revolution into action, and you have access to an elastomer that can find a home in any environment.
The parallel between rubber and a polyurethane elastomer are easy to reproduce, but the point where rubber begins to fail is the launching point at which the polyurethane version takes to the sky. For example, the viscosity and elasticity rating of a leading rubber will invariably grow fatigued as time passes. Polyurethane can be manipulated at the molecular level to minimize and even eliminate this phenomenon, relegating elastomer fatigue a thing of the past. Having stated that the elastomer is infinitely open to chemical design, it’s time that we added a little colour and shade to this vague outline. The adaptable nature of a polyurethane ‘system’ arises from the mixing of several streams of chemicals. These production streams blend catalysts and oxidants along with a soup of isocyanates and polyols to form an organic chemical base that possesses either thermosetting or thermoplastic properties. The linkages between the molecules and the way in which these chains settle is where the magic of chemistry occurs.
The synthetic rubber products created by this coming together of organic molecules takes form as impact-resistant screens for mining, as biomedical rubber tubing, and as products that can deform and resume their shape under countless strikes from heavy objects moving at incredibly fast rates. Imagine polyurethane wheels, with each surface designed to grip any floor while repelling oil and chemical sludge. In coming full circle in this discourse, the design characteristics of polyurethane fit seamlessly between the soft elastomer products and hardened plastic assemblies that are made from this polymer, thus positioning the compound as a highly affordable and adaptable material, one that’s as at home in a domestic environment as it is in heavy industry.