Bioplastics based on polyhydroxybutyrate (PHB)
PHBs are produced by microorganisms such as bacteria or plants in response to conditions of physiological stress – mainly when nutrients are limited. PHBs are biodegradable polymers, with potential to replace fossil-derive polymers. PHB is very similar to polypropylene, which is used in a wide variety of fields including packaging, ropes, bank notes and car parts. It is a transparent film, which is also biodegradable.
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PHB is harvested from bacteria.
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It is good for packaging applications and has been commercialized as a cost-effective polymer. It has also been used in the medical industry for internal structure and absorbable sutures.
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PHB comes from a renewable source. The PHB nanofibers were found to degrade completely after 3 weeks. Non-toxic. Compostable.
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Water-insoluble and relatively resistant to hydrolytic degradation. Good oxygen permeability Good ultra-violet resistance. Poor resistance to acids and bases. Soluble in chloroform and other chlorinated hydrocarbons . biocompatible. Tensile strength of 40 MPa – similar to polypropylene. Sinks in water.
Resources
Getachew, A., Woldesenbet, F. Production of biodegradable plastic by polyhydroxybutyrate (PHB) accumulating bacteria using low cost agricultural waste material. BMC Res Notes 9, 509 (2016). https://doi.org/10.1186/s13104-016-2321-y