Trials have been conducted towards products that help keep toilets that smell nice and stay clean at all times. A Coventry University spin-out company Exilica specialising in particle technology has joined forces with another SME to explore the potential of a pioneering new product. Exilica has developed and patented a unique technology which allows long-lasting fragrances to be manufactured into a variety of plastics and other polymer-based materials. The company recently collaborated with Birmingham-based Barkley Plastics and fragrance firm Seven Scent to create a scented floor tile, and has launched a trial run of the product in toilets on Coventry University’s campus. Using Exilica’s micro-particle technology, the floor tiles have been loaded with both a fragrance and an anti-bacterial agent, ensuring the toilets smell nice and stay clean at all times.

The particles developed by Exilica are tiny spheres which act like microscopic sponges, capable of absorbing twice their own weight in a variety of other substances - including scents - and then discharging them via a slow release chemical mechanism for several years. What is unique about the technology is the particles’ ability to blend seamlessly into any polymer-based material without affecting that material’s properties, potentially opening the door to revolutionary applications in industries such as healthcare, cosmetics and manufacturing. These spherical particles are produced from poly (1-methylpyrrol-2-ylsquaraine) or PMPS, which was discovered in 1966 but overlooked as it was a black intractable powder. In 2005 a scanning electron microscope (SEM) image of PMPS particles was published revealing that they were uniform spheres with a diameter of 1.3 µm. Later research found that the spheres vary in size up to a diameter of 4 µm, with the diameter range peaking around 1.9 µm. These particles are insoluble, do not melt when heated in air and decompose, although this decomposition doesn’t really affect the structural integrity of the parti cles until over 300°C. The PMPS particles developed by Exilica act like micro sponges and can absorb every metal of the periodic table, as well as other small organics such as fragrances and organic anti-bacterials. “They are the right size and shape, and are robust enough, to be compounded into polymers,” explains Technical Director Daniel Lynch. “They can be used as a delivery vehicle to carry chemical actively into polymer, or rubber, matrices.” The particles are solid but consist of an internal porous network with unique chemical properties that not only allows them to absorb at least twice their own body weight in fragrance formulation but also aids dispersion of the fragrance throughout the polymer mass. This, combined with their resistance to high processing temperatures with minimal weight loss, makes them well suited to carrying complex fragrances.

A number of other small-scale trials have taken place for Exilica’s technology with a variety of companies involved in odour masking and positive fragrancing, including those exploring the use of scents in textile fibres, paints, wallpapers and automotive interiors. Fragrances and deodorants for plastics are used in a variety of applications and are playing a growing role in marketing food and beverage packaging and in consumer products for the home, as per-bpf /plastipedia.com. Due to processing temperature concerns, fragrances are better suited to olefins rather than higher temperature plastics such as nylon or PET. Fragrances are typically incorporated into masterbatches for later addition during extrusion or moulding or the plastic part. Instead of more traditional methods of releasing fragrances into the environment such as sachets, candles and sprays, fragrances are now increasingly being embedded in consumer goods such as laundry baskets, storage containers, and sink stoppers to impart scent into the environment. In industrial applications, such as scents for hotels, offices and public areas, fragrances are being encapsulated in both polymers and fibres. Home fragrance diffuser systems that have historically used liquids or gels are moving towards use of fragrance encapsulated in solid polymer instead. Fragrances delivered in various plastic parts are being used in stores to create a mood and can be used for marketing purposes, bringing products to the consumers’ attention, particularly in food and beverage packaging. Other plastic applications include sachets filled with scented plastic beads and room air fresheners. Masking unpleasant odours in applications such as dust bin bags or household chemical containers is also an area where fragrances can help.