Polyhydroxybutyrate co-hydroxyvalerate

Yagmurlu, M. R Korkusuz, R Gursel, I. Korkusuz, P Ors. U. and Hasirci, V. Sulbactam-cefoperazone polyhydroxybutyrate-co-hydroxyvalerate (PHBV) local antibiotic delivery system In vivo effectiveness and biocompatibility in the treatment of implantrelated experimental osteomyelitis. J. Biomed. Mater. Res. 1999, 46 494-503. 

Barak, P., Coquet, Y., Halbach, T.R.. and Molina, J.A.E., 1991, Biodegradability of polyhydroxybutyrate (co-hydroxyvalerate) and starch-incorporated polyethylene plastic films in soils. J. Environ. Qual. 20 173-179. 

PCL (polycaprolactone), PEA (polyesteramide), PHBV (polyhydroxybutyrate co-hydroxyvalerates), PHBO (polyhydroxybutyrate co-hydroxyoctonoate), PBSA (poly(butylene succinate/adipate)), PBAT (poly(butylene adipateco-terephthalate)),... 

Specifically, 70-30 parts poly(hydroxy-butyrate-co-hydroxyvalerate) (4 mol% valerate) or polyhydroxybutyrate was mixed with 30-70 parts PCL in an internal mixer at 100° or 160°C in the presence of 0-0.5 parts DCP or DBP radical initiator. Blends were characterized by SEM, mechanical properties, selective solvent extraction, and FTIR. 

The nomenclature of PHAs and their classification are still in the process of evolving, because new structures are continuing to be discovered. The main biopolymer in the PHA family is a homopolymer polyhydroxybutyrate (PHB). The most conunon copolymer is poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), whose chemical structure is presented in Figure 9.4. However, there are others, such as poly(hydroxybulyrate-co-hydroxyhexanoate) (PHBHx), poly(hydroxybutyrate-co-hydroxyoctanoate) (PHBO) and poly(ltydroxybulyrate-co-hydroxyoctadecanoate) (PHBOd), for example. 

Fig. 2.7 (a) Spherulites in a thin film of polypropylene (Elaine Ann Perkins, University of Reading, UK, unpublished work, 1985), (b) spherulites in polyhydroxybutyrate-co-valerate (Reprinted with permission from Macromolecules, 2010, 43 4441-4444 Wang Z, Li Y, Yang J, Gou Q, Wu Y, Wu X, Liu Pand Gu Q (2010) Twisting of Lamellar Crystals in Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) Ring-Banded Spherulites Copyright (2010) American Chemical Society, (c) Schematic of sphaulite twisted orientations. Redrawn from Hsieh et al. (2014)... 

In the 1970s, PHBV (polyhydroxybutyrate-co-3-hydroxyvalerate) was successfully produced... 

PH A polymers comprise mainly homopolymers such as polyhydroxybu-tyrate (PHB) and polyhydroxyhexanoate (PHH), and different copolyesters, polyhydroxybutyrate-co-hydroxyalkanoates such as jx)ly(hydroxybutyrate-co-hydroxyvalerates) (PHBV) and poly(hydroxybutyrate-cohydroxyoctanoate) (PHBO)... 

Several biopolymers have been used as matrices for bionanocomposites, including starch poly(lactic acid), PLA poly(s-caprolactones), PCLs poly-hydroxyaUcanoates, PHAs, that include polyhydroxybutyrate, PHB and poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV, and poly(butylene succinate), PBS [10, 36-58, 86]. These matrices can be chemically synthesized or biosynthesized by some organisms [8, 87]. Biopolymers can be classified into four different groups depending on their synthesis (Figure 11.6) [87-89] ... 

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