Eco-friendly Plastic from Potatoes

We all know that plastic wastes are hazardous to the environment and is a big problem for the planet - our oceans are becoming clogged with the stuff and we're rapidly running out of landfill sites. Only 9 percent is recycled. Burning it contributes to greenhouse gas emissions and global warming. So could plant-based alternatives and better recycling provide an answer? 

Currently, scientists are trying to come out with a solution to get the biodegradable plastic from different vegetables. Recently a 24 years student made an eco-friendly plastic from the potatoes.   Ordinary plastics do not end even in thousands of years, while potatoes turn into a plastic cradle after stirring in just two months. Its inventor said that plastic is a major problem of the fast food industry that comes in soft drinks, packing, spoon, and straw. If this industry uses plastic potatoes, it can be very beneficial. 

On this innovation of Pontus Norquist, he has been awarded the James Dyson Award of 2018, which includes the amount of 22,000 Swedish krona.  Pontus Norquist, the 24-year-old student, made this eco-friendly plastic with water and potato husk that decomposed in a few months. For this he, he heated potato husk with water. At each stage, the soluble thickened and later placed it in the template to make spoons and other items. 

It is a kind of thermoplastic that makes it hard at high temperature but soft at low temperature. In this it can be turned into favorite shape. Bags, cutlery, and straws can also be made as potatoes are prepared for plastic for special food industry, where only a large number of plastic is used. 

Most plastics are still made from petro carbons, but some the world’s largest companies are betting that plastics made from plants, not petroleum, will be the best choice for the future. Consumers may already be willing to pay a premium for renewably-sourced products with smaller carbon footprints, and major manufacturers believe that bioplastics will only become more price-competitive as oil prices rise and oil supplies dwindle. They are investing huge amounts to advance the science and technologies and to increase bioplastics production. 

Up to 30 percent of Coca-Cola’s “Plantbottle” plastic comes from sugar cane. Although billions of these bottles have been used around the world since their introduction in 2009 at the UN Climate Change Conference in Copenhagen, bioplastic still comprises less than 1 percent  of the 30 million tonnes of plastics produced per year. But throughout Europe and Asia bioplastics are beginning to replace conventional oil-based plastics in thousands of products. Even for car components—hoping to capture two-thirds of the global market for petroleum-free plastic, Toyota has plans to grow its bioplastics division into a four billion yen (C$475,000,000) business by 2020. 

Cargill is the largest commercial producer of bioplastic in the US. Its NatureWorks plant in Nebraska begins with corn sugar to make packaging material and fibers for products from yogurt containers to teabags to diapers. (It also made the “too-noisy” compostable bioplastic SunChips bags. Another quieter, version has just been introduced.) Then there’s SpudWare plastic cutlery, washable, reusable, compostable, and made from 80% potato starch and 20% soy oil. As heat resistant and strong as conventional plastic cutlery, it is also designed to biodegrade in just six months. 

All bioplastics begin with a plant’s naturally-occurring sugars or starches, and sugar cane or corn starches are often the preferred feedstocks. But potatoes, which can contain from 13% to as much as 23 percent dry matter (starch) depending on their water content, may be ideal for some plastics. “Potatoes are starch factories,” according to Dr. Qiang Liu, who headed the bioplastics research team of the BioPotato Network, funded by Agriculture and Agri-Food Canada’s Agricultural Bioproducts Innovation Program from 2008 to March of this year.

More than 30 food scientists, molecular biologists and plant production specialists across Canada investigated possible functional food-ingredient and non-food applications in an effort to find new, more profitable crops for Canada’s potato farmers, whose crop was valued at nearly $1.13 billion in 2009. 

Most plastics are polymers—natural or synthetic chains of smaller molecules (monomers)composed of carbon and hydrogen alone, or that include oxygen, nitrogen, chlorine, or other elements. (The word itself comes from the Greek “plastikos,” which means “capable of being shaped or molded.”) 

Fermentation, heat, chemical manipulation or even microbes are used to turn a sugar or starch feedstock into the building blocks—polylactic acid, hydroxymethylfurfural or poly-3-hydroxybutyrate—used as the basis for the even more complex and varied chemical creations we call “plastic.” Once thermoset plastics solidify, their polymer strands form tangled bonds that cannot be undone without destroying the plastic, and they are tough and temperature-resistant. In contrast, thermoplastics can be moulded, melted, then moulded again. Transparent polylactic acid (PLA) is obtained from starch fermented into lactic acid, then polymerised, and has characteristics similar to polyethylene and polypropylene. It can be processed with equipment already used for petroleum-based plastics for a wide range of products, including computer casings, food and other packaging, even biodegradable medical implants. Thermoplastic starch(TPS), currently the most widely used bioplastic, can be derived from potatoes or from corn. Plastarch Material (PSM) is a biodegradable, thermoplastic resin, composed of starch modified to give it heat-resistant properties and combined with other biodegradable materials to improve flexibility or give it other characteristics, and is used for food packaging and utensils, plastic bags, temporary construction tubing and stakes, foams, films, window insulation, and planters, and some are biodegradable in compost, wet soil, and water, and by some microorganisms. Scientists are now experimenting with microbes that can convert natural sugars and oils into biodegradablepolyhydroxyalkanoate (PHA) materials. 

“People do confuse biodegradability and bioplastic. Not all bio-based products are biodegradable, and not all biodegradable products are bio-based,” Liu says, explaining that biodegradability can be engineered into a bio-based or petro-based product. High temperatures are required to break most bioplastics like PLA down, usually in commercial facilities that maintain temperatures of between 40° C to 65° C. But Liu notes that using renewable feedstocks such as potato starch or dry matter to produce carbon-based polymer materials will benefit the environment, whether or not the end product is biodegradable.

The production of one metric ton of bioplastic generates between 0.8 and 3.2 fewer metric tons of carbon dioxide than one metric ton of petroleum-based plastics. Thus, the development of bioplastics will help control and even reduce CO2 emissions, says Liu, “helping to meet global CO2 emissions standards set by the Kyoto Protocol, and provide for an improved environmental profile.” 

The pharmaceutical industry has been using potato-based TPS for drug capsules for more than a decade, recognizing pure starch’s ability to absorb humidity. The BioPotato Network’s research goals included manipulating potato starch to produce bioplastics with stronger mechanical properties and greater water resistance and to make them easier to work with. “In some cases, it is easier to modify potato starch than corn starch,” Liu observes, and he and his team were able to make some significant discoveries. “We successfully developed various novel starch-based bioplastic products,” he says, including TPS with fibre from potato and pea, TPF using potato pulps derived from different potato varieties, TPS with PLA and nanofiller, and TPS combined with a common mineral nanoclay. “A significant outcome was finding a paraffin wax that maintains biodegradability while reducing moisture sensitivity compared to PLA as an additive.” The scientists wanted to focus next on starch-based foam to replace current non-bio-based foam. “Unfortunately, the program ended in March 2011,” says Liu, but he hopes the government will consider renewing it. Commercializing products the network developed will also be challenging, he admits, but potential investors in New Brunswick, Quebec, Ontario and Manitoba have already expressed interest. 

Bioplastics are not just substitutes for conventional petroleum-based plastics—for some applications, they are superior. In the future, they may add valuable opportunities for potato growers and processors, while leading to a cleaner and more sustainable world for us all.