Posted on June 5, 2013 at 8:00 AM by Iowa Corn
Vulcanized, natural rubber, discovered in the 1800s, was one of the first successful attempts to create a functional, synthetic material from natural resources. In the 1930s, more research went into plant based plastics, and in 1941 Henry Ford used bio-based panels for the body of a car that was presented at the Dearborn Show in Michigan. Using plastic composites in cars has proven to be a safe alternative to heavy steel, which is easily crushed in an accident and is a drain on fuel economy based on its weight.
Continuous research went into polymer science to produce plastics for specific applications; however, use of agricultural, bio-renewable feedstock for plastic materials remained a novelty for some time due to the discovery of petroleum.
The ease and versatility of petroleum plastic manufacturing enabled affordable consumer goods with ever increasing volumes produced and subsequently discarded in landfills. The seemingly nondestructive material started to create waste management issues and eventually resulted in the call for materials with satisfactory functionality for a defined period of time. Combined with the awareness of finite petroleum resources, plastic manufacturing began to re-focus research on natural feedstock to make renewable, recyclable consumer goods.
Bioplastics are now materials with a wide variety of properties that can imitate and even surpass the performance of petroleum based plastics. They can be biobased combinations of plant and petroleum derived components, completely plant based with all the required performance of plastics, and/or engineered to be biodegradable, meaning the material will decompose in a natural environment or compostable, meaning that it is being subjected to a specific environment for decomposition. Biobased plastic doesn’t necessarily degrade; it can be made as stable and durable as petroleum based plastic. The term “biobased” refers to the use of the carbon utilized for the polymer originating from renewable sources and is referred to as biogenic carbon. Identification of the carbon source is determined by the C14 signature, a radioactive carbon formed in the upper atmosphere and utilized through photosynthesis by plants.
Bioplastics can be based on cellulose, natural oils, protein, or starch. Cellophane has been made from cellulose for 100 years now and is used in packing. Its popularity lies in its 100% biodegradability. Cellulose can be transformed into fibers that imitate silk, are strong, durable and easy care. Starch is the base for biodegradeable PLA food containers and disposable cutlery. Medical sutures based on PLA dissolve completely in about three months. Production of PLA is projected at over a million tons per year by 2020 and continuous research is expanding its application and performance. Natural oils can be polymerized into thermoset composites further strengthened with natural fibers to achieve the toughness of steel and utilized in machinery, construction, and many other applications. Protein based polymers are applied as coatings on a multitude of products that require non-toxic, biodegradable performance for food packaging and pet food storage.
Environmental and health concerns have raised questions on the use of certain, long established plastic chemistries, and replacements have already been found in plant derived chemistry. A compound with exceptional performance made from corn is isosorbide and its derivative. Initially developed for medical use, it has been evaluated as an alternative, bio based polymer additive with unusual and great benefits. Newly developed, economical isosorbide process methods enable a cost competitive alternative to petroleum based additives.
Biobased plastics can achieve the balance of required utility without adding further to our global carbon footprint.