China
Africa
Explore chapters and articles related to this topic
PHB Production, Properties, and Applications
Published in Abdullah Al-Mamun, Jonathan Y. Chen, Industrial Applications of Biopolymers and their Environmental Impact, 2020
M.A.K.M. Zahari, M.D.H. Beg, N. Abdullah, N.D. Al-Jbour
Poly-3-hydroxybutyrate P(3HB) and its copolymers with 3-hydroxyvalerate (3HV), poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), are the best known representatives of the PHA family. These polyesters have attracted widespread attention, as environmentally friendly polymers which can be used in a wide range of agricultural, industrial, and medical applications [6]. P(3HB) belongs to the polyesters class that was first isolated and characterized in 1925 by French microbiologist Maurice Lemoigne [7]. It is produced by different types of microorganisms, such as Cupriavidus necator or Bacillus megaterium. The polymer is primarily a product of carbon assimilation (from glucose or starch) and is employed by microorganisms as a form of energy storage molecule to be metabolized when other common energy sources are not available. Figure 4.1 shows the generic formula for PHAs, where x is 1 (for all commercially – relevant polymers) and R can be either hydrogen or hydrocarbon chains of up to around C16 in length [8]. A wide range of PHA homopolymers, copolymers, and terpolymers have been produced, in most cases at the laboratory scale. A few of them have attracted industrial interest and have been commercialized in the past decade.
Properties of gelatin and poly (3-hydroxybutyrate-co-3-hydroxy-valerate) blends
Published in Ai Sheng, Energy, Environment and Green Building Materials, 2015
Ya Li, Jing-Kuan Duan, Ya-Juan Wang, Lan Jiang, Kai-Qi Shi, Shuang-Xi Shao
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is one of bacterially derived polyesters. These polymers have recently attracted considerable attention by scientists from academic and industry mainly because they are biodegradable thermoplastics and elastomers that can be processed through conventional extrusion and moulding process[Avella, M. & Errico, M. E. 2000, Chiellini, E. 2001]. The drawbacks of PHBV are the high cost compared to that of petroleum-based commodities plastics. To reduce the cost or improve the performance properties of PHBV, studies on the modification of PHBV through copolymerization and blending with other polymers has been made in the area of industrial production, medicine and surgical[Avella, M.et al 2000, Chen, G. X.et al 2002, Ferreira, B. M. P.et al 2002, Fei, B.et al 2004, Liu, H. L.et al 2007, Meng, W.et al 2007].
Selected Topics
Published in Charles E. Carraher, Carraher's Polymer Chemistry, 2017
PHB has n = 1 and R = methyl. PHB is biocompatible and is a metabolite normally present in blood. Thus, a wide range of biomaterial uses can be envisioned for it. The copolymer of PHB and PHV (where R = ethyl and n = 1), poly(-3-hydroxybutyrate-co-3-hydroxyvalerate), is being used as a packaging material. Compared to PHB, the copolymer is tougher, less rigid, and easier to process.
End-of-waste life: Inventory of alternative end-of-use recirculation routes of bio-based plastics in the European Union context
Published in Critical Reviews in Environmental Science and Technology, 2019
Demetres Briassoulis, Anastasia Pikasi, Miltiadis Hiskakis
Multi-extruded Mater-Bi and PHAs:Mater-Bi TF01U/095R aliphatic polyester (Novamont): can be mechanically recycled up to 10 times with an acceptable loss in mechanical and thermal properties (Lopez et al., 2012).Mater-Bi YI014U/C starch based (Novamont): should be destined to organic recycling, as its recyclability is very poor (general loss of recyclability in 2 cycles) (Lopez et al., 2012).PHBV Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Biopol (14% valerate) (Zeneca Bioproducts): tensile strength maintained with a slight decrease of 7.1% after the 5th reprocessing cycle. No change for impact strength. MW decreased after the 3–5 cycles (8.7%, 13.5% and 16.6%, respectively) and crystallinity decreased by 21% after 5 cycles (Zaverl, Seydibeyoglu, Misra, & Mohanty, 2012).PHB Poly(3-hydroxybutyrate) copolymer: showed reduced viscosity by 79% and tensile strength by 10% after 10 cycles of reprocessing (Soroudi & Jakubowicz, 2013).
Surface modification of PHBV nanofiber mats for rapid cell cultivation and harvesting
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Young-Gwang Ko, Young-Jin Kim, Won Ho Park, Donghwan Cho, Ho Yun Chung, Oh Hyeong Kwon
Tissue engineering and cell therapy are rapidly expanding fields aimed at restoring diseased or defective human tissues [1–4]. To engineer artificial tissues, biomimetic scaffolds that are biocompatible, biodegradable, and provide an appropriate framework and surface for cell attachment, migration, and growth are necessary [5–9]. Specifically, scaffolds should mimic the native extracellular matrix (ECM). Furthermore, functional cell sources for regeneration of target tissues that maintain differentiation potential must be carefully considered for mass cultivation in vitro [10–18]. Thus, investigation of a novel cell culture surface and harvesting method using a biomimetic scaffold that allows for differentiation without any damage is required. For preparation of biomimetic scaffolds, a number of researchers have used the electrospinning method [19–24]. Electrospun nanofibrous scaffolds have a structure similar to natural ECM, and their highly porous structure and large surface area facilitate initial cell attachment, spreading, and growth on a nanofibrous nonwoven surface. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) has reasonable biocompatibility, mechanical, and biodegradability properties for use as a cell culture substrate. In addition, nanofibrous PHBV mats were reported to induce significant cell attachment and proliferation compared to those with a film substrate by providing sufficient spreading sites for cells. For this reason, we prepared a PHBV nanofiber mat scaffold using an electrospinning method [25–28].
Thermal and thermo-oxidative stability and kinetics of decomposition of PHBV/sisal composites
Published in Chemical Engineering Communications, 2018
C. Moliner, J. D. Badia, B. Bosio, E. Arato, T. Kittikorn, E. Strömberg, R. Teruel-Juanes, M. Ek, S. Karlsson, A. Ribes-Greus
The search of commercially viable green products based on natural resources for different applications is in continuous development. New obtaining routes to produce natural based goods with improved mechanical and thermal properties are being studied to obtain biodegradable products to be used as replacement of the current petroleum-based, non-biodegradable polymers, in many sectors such as automotive, household or packaging (Kowalczuk et al., 2014, Rydz et al., 2015). In this sense, materials such as wood or natural fibres are commonly used to reinforce thermoplastics due to their low cost, abundant availability, high performance and low density (Fernandes et al., 2004). These natural fibres also become eco-friendly replacements to the use of carbon, glass or aramid fibres (Faruk et al., 2012), and have been used to reinforce common polymer matrixes such as polyethylene (Zhao et al., 2014) or poly(ethylene terephthalate) (Santos et al., 2014), for instance. From a wider eco-responsible approach, biocomposites prepared by means of biopolymers and biofibres represent a real alternative. For the particular case of sisal-reinforced biocomposites, matrixes such as polylactide (Gil-Castell et al., 2014, 2016) have been proposed. Among all the biopolymers produced from renewable resources, polyhydroxyalkanoates (PHAs) have a very wide range of properties and applications (Weng et al., 2010, Bledzki and Jaszkiewicz, 2010). Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is among the most popular PHAs which, despite its biodegradability and biocompatibility, presents a low strength impact which makes it non suitable for determined technical applications. Therefore, the use of sisal stands out as a feasible reinforcement for PHBV (Badia et al., 2014, Kittikorn, 2013).