Natural Products That Could Replace Plastic
Drinking straws and polythene bags may be bearing the brunt of the backlash, but the true scourge of single-use plastics is our sheer overreliance on them. From transport to manufacturing to food services, plastic is everywhere, and combatting this “white pollution” will require a sea change in the material itself.
Fortunately, scientists, engineers and designers are shifting their focus to ecologically friendly alternatives that create circular, low-waste ecosystems – liquid wood, algae insulation, and polymer substitutes made from fermented plant starch such as corn or potatoes, for example.
These alternatives do more than stem the growing tide of plastics: they also address issues such as safely housing a growing population, offsetting carbon emissions, and returning nutrients to the earth.
To transform one of the world’s most abundant resources into something with utility and sustainability takes a special kind of alchemy. Stone wool comes from natural igneous rock—the kind that forms after lava cools – and a steelmaking byproduct called slag; these substances are melted together and spun into fibres, a little like candyfloss.
Unlike fibreglass insulation (made with recycled glass), or foamed plastic (the conductive materials often used to block heat transfer in attics, roofs and crawlspaces), stone wool can be engineered to boast unique properties, including fire resilience, acoustic and thermal capabilities, water repellancy and durability in extreme weather conditions.
Over the past few years, stone wool has gained traction with eco-conscious architects and designers as they search for more sustainable building materials that are still cost-effective and aesthetic. The Rockwool Group is a leading manufacturer of stone wool insulation, running production facilities in Europe, North America and Asia. The company has installed stone wool in commercial and industrial buildings across the globe, including London’s O2 Arena and the Hong Kong Airport.
As wildfires and floods increase in frequency and severity, Stone Wool may also give homeowners an extra measure of safety in natural disasters.
Mushrooms aren’t just a flavour-packed addition to ravioli or ragu (or a sparkplug to the occasional psychedelic adventure); soon, tree-hugging fungi and forest-floor toadstools may replace materials like polystyrene, protective packaging, insulation, acoustic insulation, furniture, aquatic materials and even leather goods.
MycoWorks, a team of creative engineers, designers and scientists, is working to extract the vegetative tissues of mushrooms and solidify them into new structures, curating fungi as one might other organic materials like rubber or cork. Another company, New York-based Evocative Design, uses mycelium as a bonding agent to hold together wood paneling, as well as for flame-retardant packaging.
Mushrooms consist of a network of filaments called hyphae. When growth conditions are suitable, fruiting bodies – the structures specialised for the production of spores – make an often sudden appearance; so-called mycelial products are thus easy to culture and germinate.
Mycelium can be grown in almost any kind of agricultural waste (think sawdust or pistachio shells); mushrooms grow together within the material, which can be configured into any shape, forming natural polymers that adhere like the strongest glue. By baking the fungi at precise temperatures, they are rendered inert, thereby ensuring that the mushroom doesn’t suddenly sprout again in a rainstorm. While chanterelles, shiitaki and portobello may go better with pizza than mushroomy plaster, one thing is clear: the future is fungi.
Cement, concrete’s primary ingredient, accounts for about 5% of the world’s carbon dioxide emissions. Researchers and engineers are working to develop less energy-intensive alternatives, including bricks made with leftover brewery grains, concrete modelled after ancient Roman breakwaters (Romans made concrete by mixing lime and volcanic rock to form mortar, a highly stable material), and bricks made of, well, urine.
As part of his thesis project, Edinburgh College of Art student Peter Trimble was working on an exhibit that was supposed to feature a module on sustainability. Almost by accident, he created “Biostone”: a mixture of sand (incidentally, one of Earth’s most abundant resources), nutrients, and urea – a chemical found in human urine.
Pumping bacterial solution into a sand-filled mould, Trimble devised hundreds of experiments over the course of a year until he tweaked the recipe. The microbes eventually metabolised the mixture of sand, urea, and calcium chloride, creating a glue that strongly bound the sand molecules together.
Trimble’s design offers an alternative to the energy-intensive methods with a low energy biological process of microbial manufacturing. Biostone produces no greenhouse gases and uses a widely available raw material. While Trimble's material would require reinforcement to be as strong as concrete, it could become a low-cost way of building temporary structures or street furniture.
At the very least, Biostone has spawned a discussion on ways in which industrial manufacturing can be made more sustainable, particularly in Sub-Saharan Africa and other developing countries where sand is readily available.
These bio-bricks do have an environmental downside, however: the same bacterial metabolism that solidifies them work also turns the urea into ammonia, which can pollute groundwater if it escapes into the environment.
A greener particleboard
Despite what it sounds like, particleboard – those rigid panels made of compressed and veneered wood chips and resin used in furniture and kitchen cabinetry throughout the world – hasn’t actually a place in the green-building pantheon. That’s because the glue that binds particleboard’s wood fibres traditionally contain formaldehyde, a colourless, flammable, strong-smelling chemical and known respiratory irritant and carcinogen. That means your faux-wood Ikea shelf is quietly “off-gassing” toxins into the air.
One company, NU Green, created a material made from 100% pre-consumer recycled or recovered wood fibre called “Uniboard”. Uniboard saves trees and avoids landfill, while also generating far fewer greenhouse gases than traditional particleboard, and contains no toxins. That’s because Uniboard has pioneered the use of renewable fibers like corn stalks and hops, as well as no added formaldehyde (NAF) resin instead of glue.
It’s no secret that petroleum extraction, which is required to produce plastic, has devastating environmental consequences. Worse still is disposing of the plastic itself: the toxic chemicals contained in plastic often leach into foods, beverages and groundwater.
Shockingly, recycling merely slows down the journey of plastics to landfills or oceans, where the material simply fragments into smaller and smaller bits that never completely biodegrade. Some reports predict that, by 2030, 111 million metric tons of plastic will wind up in landfills and oceans . Recycling is a step in the right direction, but to truly reverse course, we need to look toward plastic alternatives and renewable resources for a sustainable future.