Synthetic polymers have long been the foundation of packaging materials. However, because synthetic polymers are non-biodegradable, our reliance on them in the packaging industry has led to serious ecological problems. Here are some examples on how long it takes for some packaging to degrade:
A Plastic Bag…………………….. 10-20 years
A Plastic Film Container…….. 20-30 years
Foamed Plastic Cups……… 50 years
Plastic Beverage Bottles…… 450 years
Biodegradable polymers are intended to reduce waste. Biodegradable is a type of material that can decompose into natural elements under the action of microorganisms within a short period of time after disposal – typically a year or less. It is believed that biodegradable polymers will replace synthetic polymers at a low cost, thereby producing a positive effect both environmentally and economically.
Types of Materials Used
The property of polymers to biodegrade is defined by their structure and does not depend on the raw material from which they have originated from. For example, products made of polyethylene will not biodegrade even if they are made from bio-based polyethylene, while many aliphatic polyesters, such as polyhydroxyalkanoates, polylactic acid etc. will biodegrade irrespective of the resource used for their production. As a consequence, biodegradable polymers can be both bio-based and fossil-based, and their biodegradability will depend on their structure, not their origin.
Bio-based materials can be obtained from two sources: 1) the direct production of biopolymers by microorganisms, algae or plants or 2) the production of bio-based monomers and their further polymerization. In the first group, polymers such as polyhydroxyalkanoates (PHA), polysaccharides and oligosaccharides (cellulose, hemicellulose, starch, inulin, pectin, chitin and chitosan), and others such as proteins, poly(amino acid)s, or lignin can be found. In the second group, the most widely known example includes lactic acid (and the respective polymer, PLA). Examples on biodegradable fossil based materials can be found in some polyurethanes and polyesters, for example.
The biodegradable polymers that have found application in packaging are starch, cellulose, chitosan, poly(lactic acid) (PLA), polycaprolactone (PCL), and polyhydroxybutyrate (PHB) to name a few. Many materials can be mixes or blends containing synthetic components, such as polymers and additives to improve the functional properties of the finished product and to expand the range of application. However, if additives and pigments are also based on renewable resources, one can obtain a polymer with approximately 100% weight of biodegradation compounds.
Current Trends and Market Size
The current trends in biodegradable packaging include the use of blends of different biopolymers like starch-PLA blends, starch-PCL blends etc., as well as developing new bioplastics with improved mechanical, thermal, and barrier properties.
According to a recent market report on Biodegradable Plastics Market, production of PLA is the largest segment by type with a market share of more than 45.1%. This is due to PLA’s mechanical properties and ease of processability. In terms of value, starch blends are expected to account for the largest share in the market due to their comparative high cost compared to PLA.
The largest segment by application of biodegradable plastics is in packaging, both in terms of value as well as volume, with a market share of more than 60.3%. This is due to the fact that biodegradable plastics are being increasingly used to manufacture single use packaging materials such as shopping bags, disposable cutlery, etc.
The forecasted increased use of biodegradable plastics in the future is attributed to increasing environmental awareness, as well as the implementation of stricter environmental regulations.
Commercialized Biodegradable Products
Many companies like Novamont, BASF, Biomer, National Starch, and DuPont are producing biodegradable polymers. Here are some examples on the real-life use of biodegradable polymers.
Since 2011, a bottled water company, Redleaf Water, began distribution of the industry’s first biodegradable and recyclable water bottle. The solution was produced by Arizona-based ENSO Plastics, LLC. The company, dedicated to providing environmentally friendly solutions, has worked for three years to perfect a bottle that can be both PET recyclable and biodegradable. The BIO BOTTLE will biodegrade naturally in aerobic and anaerobic (landfill) conditions within one to 15 years, as opposed to 450 needed for standard PET bottles.
In 2010, a company called THE WAY WE SEE THE WORLD presented Loliware – a set of intriguing, squishy, colorful glasses made to replace the standard plastic cups. Loliware is entirely made out of agar agar, a seaweed extract. It can be thrown into the grass after it is used, as the extract that it is made from nurtures the growth of plants or you can simply eat it as it’s non-toxic, all-natural and FDA approved.
Ahlstrom has developed NatureMold™ – a new biodegradable and compostable molding material for food packaging for a wide range of food applications. The material can be utilized in the temperature range of -40˚C (-40˚F) to 220˚C (428˚F), both in the oven and microwave, with great wet strength and grease resistance. It is made of paperboard and Genuine Vegetable Parchment (GVP), which is 100% cellulose.
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