ISSN: 2319-8753 International Journal of Innovative Research in Science, Engineering and Technology (An ISO 3297: 2007 Certified Organization) Vol. 3, Issue 2, February 2014 Copyright to IJIRSET www.ijirset.com 9598 Polyhydroxybutyrate - a Biodegradable Plastic and its Various Formulations Sabbir Ansari 1 , Tasneem Fatma 2 Research Scholar, Department of Biosciences, Jamia Millia Islamia, New Delhi, India 1 Professor, Department of Biosciences, Jamia Millia Islamia, New Delhi, India 2 Abstract: Plastic waste is increasing every year and the precise time needed for biodegradation is unknown. Environmental awareness has driven the development of new biodegradable materials, especially for single use plastic items. Polyhydroxybutyrate (PHB), biodegradable thermoplastic polyester is emerging out as a boon to overcome the problem of plastic waste accumulation. However, it has some drawbacks like moreover, it is still much more expensive and lacks mechanical strength compared with conventional plastics, high crystallinity, stiff and brittle, thereby resulting in poor mechanical properties with a low extension at break, which limits its range of applications. Here we report some PHB based blends which improved the quality of plasticizers. Keywords: Polyhydroxybutyrate, biodegradable thermoplastic polyester, crystallinity, plasticizers I. INTRODUCTION In the past decades, an enormous market for biologically compatible products evolved. In this context, biologically degradable polymers are still rather underdeveloped. Although well known in principle, application of these materials has been limited to only specialized usage in medicine. However, there is without doubt great commercial potential of biodegradable plastics as substitute for polyolefin commodities like polypropylene (PP) and polyethylene (PE), but currently the high costs and the limited availability of these materials stand in the way of a broad introduction to a ready market [1] [2]. One of these promising materials is poly[(R)-3-hydroxybutyric acid (PHB). PHB has been the subject of extensive studies as an environmentally friendly polymeric material. Polyhydroxybutyrate (PHB) is a polyhydroxyalkanoate (PHA), a polymer belonging to the polyesters class that are of interest as bio-derived and biodegradable plastics [3]. The poly-3- hydroxybutyrate (P3HB) form of PHB is probably the most common type of polyhydroxyalkanoate, but other polymers of this class are produced by a variety of organisms: these include poly-4-hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO) and their copolymers. Poly (hydroxyalkanoates) (PHAs) belongs to a family of natural polyesters having a structure with the same three- carbon backbones and differing alkyl groups at b or 3 positions [4]. Such materials become more attractive when their mechanical properties compare favorably with those of commercial polymers. This is well illustrated by the estimate that consumption of biopolymers will grow to approximately 100 million metric tons/year by 2020 in Europe, while the perspective for 2008 also shows a growing market for biodegradable polymers [4]. Polyhydroxybutyrate (PHB) offers many advantages over traditional petrochemically derived plastics. In addition to its complete biodegradability, PHB is formed from renewable resources. It possesses better physical properties than polypropylene for food packaging applications and is completely nontoxic. The poor low-impact strength of PHB is solved by incorporation of hydroxyvalerate monomers into the polymer to produce polyhydroxybutyrate-co-valerate (PHBV), which is commercially marketed under the trade name Biopol. Like PHB, PHBV completely degrades into carbon dioxide and water under aerobic conditions [5].