Bioplastics are plastic materials produced from renewable biomass sources. Not all bioplastics are biodegradable nor biodegrade more readily than commodity fossil-fuel derived plastics. Bioplastics are usually derived from sugar derivatives, including starch, cellulose, and lactic acid.
Sources for making bioplastics include:
- Plant material rich in starch; corn, potatoes, rice, etc.
- Vegetable fats and oils.
- Plant material rich in oil; oil seeds, especially palm, soy, rapeseed, castor oil, etc.
- Plant material rich in cellulose; Hemp, straw, agricultural waste, wood chips, sawdust, forest waste, plant stalks.
- Recycled food waste.
- Plastic bottles and other containers using microorganisms.
Types of bioplastic
|Type||Examples of sources||Material attributes|
|Starch Bioplastic||corn, potatoes, rice||Pure starch is able to absorb humidity, and is thus a suitable material for the production of drug capsules by the pharmaceutical sector. However, pure starch-based bioplastic is brittle.|
|Cellulose based||Hemp, agricultural waste, forest waste, saw dust, various plants||Cellulose can become thermoplastic when extensively modified. An example of this is Cellulose Acetate, which is expensive and therefore rarely used for packaging. However, cellulosic fibers added to starches can improve mechanical properties, permeability to gas, and water resistance due to being less hydrophilic than starch.|
|PLA||corn, dextrose||PLA bioplastic is similar to conventional petrochemical-based mass plastics like PS. It has the distinct advantage of degrading to nontoxic products. Unfortunately it exhibits inferior impact strength, thermal robustness, and barrier properties (blocking air transport across the membrane). PLA and PLA blends generally come in the form of granulates with various properties, and are used in the plastic processing industry for the production of films, fibers, plastic containers, cups and bottles.|
|PHB - bacterial derivation||.|
|Protein based plastics||wheat gluten, casein, soy||producing blends of soy protein with some already-available biodegradable polyesters improves the water sensitivity and cost.|
|Genetically modified feedstocks|
|Lipid derived polymers|