Characterization of Oligomeric Hydroxyalkanoic Acids from Thermal Decomposition of Palm Kernel Oil–Based Biopolyester (original) (raw)
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Production of poly-hydroxyalkanoate as secondary metabolite with main focus on sustainable energy
A B S T R A C T Poly-hydroxyalkanoate was introduced as a bio-based polymer in many countries many years ago, owing to its biocompatibility and degradation value in the nature. The importance of PHA production of plants and microorganisms is due to its biodegradability and biocompatibility of its structure and materials, which because of this property they will return to the nature and will be replaced with petrochemical plastics. These products were identified as environmentally friendly products in the 21-century. The great potential of PHA as a renewable product, to be produced from industrial waste oils. However, by producing PHA, the environment will be clear of pollutants by using the waste products of factories at first and secondly by circulating the biopolymers to the nature. In the current review, we have focused on PHA production from dairy residues, soybean oil and saponified waste palm oil and some microorganisms such as Pseudomonas, Delftia, Halomonas and E. coli. Amongst different varieties of bacteria Pseudomonas has the highest ability to produce PHA. The global shares of PHA generation in various market segments in 2013 and 2020 shows that capacity production will increase until 2020 and the most production of PHA will be in Asia due to their superior accessibility to feedstock and promising political frame.
European Polymer Journal, 2003
Medium-chain-length polyhydroxyalkanoates are produced by Pseudomonas putida strain IPT046 growing on carbohydrates. Analysis by gas chromatography and nuclear magnetic resonance of the elastomeric material revealed that PHA mcl is composed from essentially hydroxydecanoate (60-70%) and hydroxyoctanoate (20-25%) sequence units with a non-terminal double bond in about 6% of the side chains. The average molecular weight of PHA mcl is 223 kDalton and the X-ray diffractogram showed that 24% of the solid phase is crystalline. This biodegradable polyester presents a relative low glass transition temperature ()39.7°C) and melting point (56°C), is thermically stable (234°C) and displays appropriate thermomechanical properties for potential use as packaging film.
Chemical and Biochemical Engineering Quarterly, 2018
Polyhydroxyalkanoates (PHAs) are a group of biodegradable polymers produced from renewable sources by prokaryotic biocatalysts, accumulated intracellularly for energy and carbon storage. In the present study, production and characterization of PHAs synthetized by Cupriavidus necator (IPT 026 and IPT 027) and Burkholderia cepacia (IPT 119 and IPT 400) were evaluated using crude palm oil (C 16:0 = 26.44 %, C 18:1 = 54.50 %, C 18:2 = 13.41 %) as substrate (15 g L-1 crude palm oil, pH 7.0, 180 rpm, 72 h). All strains were able to synthesize novel PHA copolymers (0.10-1.45 g L-1), and IPT 027 displayed the highest production. Copolymers monomeric composition (M w = 173.78-389.30 kDa) was comprised mostly of hydroxyhexadecanoate (41.43-53.15 %) and hydroxy-9-octadecenoate (14.91-29.61 %). PHAs were predominantly amorphous, showed low polydispersity, and good thermal stability (T onset ≥ 283 °C), which increased proportionally to crystallinity. Crude palm oil constitutes an emerging alternative for PHAs production, and microorganism strains strongly affect polymer accumulation, monomeric composition, molar mass, and properties.
Biosynthesis of medium chain length polyhydroxyalkanoates (mcl-PHAs) from palm oil
2020
Medium chain length polyhydroxyalkanoates (mcl-PHAs) are biopolyesters, derived from renewable biomass resources such as palm oil. These PHAs can be converted to added value products such as biopolymers, potentially increasing the economical worth of crude palm oil. Batch experiments were set up in an orbital shaker incubator at 30°C to explore the feasibility of PHAs biosynthesized by Pseudomonas aeruginosa TISTR 1287 from palm oil. P aeruginosa was cultured under varied palm oil concentrations (0.50 to 2.00% w v-1) and initial pH 7. The concentrations of palm oil and cultivation time influenced the growth of P. aeruginosa and intracellular accumulation of PHAs. Maximum cell dry weight of 2.33 g L-1 was obtained at 0.50% w v-1 palm oil after at 44-hr cultivation. The maximum PHAs concentration of 0.65 g L-1 and content was 38.02% at 0.75% w v-1 palm oil after 72-hr cultivation. FTIR and GC-MS spectra indicated the biopolyesters are mcl-PHAs with heterogenous types of monomers. The ...
Medium-chain-length poly(3-hydoxyalkanoates) (mcl-PHA), comprising six to fourteen carbon-chainlength monomers, are natural thermoplastic polyesters synthesized by fluorescent pseudomonades. In this study, mcl-PHA was produced by Pseudomonas putida from oleic acid in aerobic shake flask fermentation. Thermal degradation of mcl-PHA was performed at temperatures in the range of 160e180 C. Thermodynamic parameters of mcl-PHA thermal degradation were determined where degradation activation energy, E d and pre-exponential factor, A equal to 85.3 kJ mol À1 and 6.07 Â 10 5 s À1 , respectively; and exhibited a negative activation entropy (ΔS) of À139.4 J K À1 mol À1 . Titration was carried out to determine the carboxylic terminal concentration and used to correlate number-average molecular weight (M n ) of the polymers. Thermally-degraded PHA contained higher amount of carboxylic terminals and lower M n compared to the initial PHA and these results coincide with the decreased M n in GPC analysis. Thermal properties of initial and degraded mcl-PHA were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermal decomposition mechanism was investigated following the analyses of the degradation products using 400-MHz 1 H NMR, FTIR spectroscopy and GC analysis. The overall decomposition reaction is the hydrolysis of ester linkages to produce hydroxyl and carboxylic terminals. A small proportion of unsaturated side chain fragments would undergo oxidative cleavage at C]C linkages, producing minor amount of low-molecular weight esters and acids. At higher temperatures, the hydroxyl terminal can undergo dehydration to form an alkenyl terminal.
Volatile Fatty Acids as Carbon Sources for Polyhydroxyalkanoates Production
Polymers
Waste of industrial origin produced from synthetic materials are a serious threat to the natural environment. The ending resources of fossil raw materials and increasingly restrictive legal standards for the management of plastic waste have led to research on the use of biopolymers, which, due to their properties, may be an ecological alternative to currently used petrochemical polymers. Polyhydroxyalkanoates (PHAs) have gained much attention in recent years as the next generation of environmentally friendly materials. Currently, a lot of research is being done to reduce the costs of the biological process of PHA synthesis, which is the main factor limiting the production of PHAs on the industrial scale. The volatile fatty acids (VFAs) produced by anaerobic digestion from organic industrial and food waste, and various types of wastewater could be suitable carbon sources for PHA production. Thus, reusing the organic waste, while reducing the future fossil fuel, originated from plasti...
Polymer Degradation and Stability, 2010
Medium-chain-length poly(3-hydoxyalkanoates) (mcl-PHA), comprising six to fourteen carbon-chain-length monomers, are natural thermoplastic polyesters synthesized by fluorescent pseudomonades. In this study, mcl-PHA was produced by Pseudomonas putida from oleic acid in aerobic shake flask fermentation. Thermal degradation of mcl-PHA was performed at temperatures in the range of 160–180 °C. Thermodynamic parameters of mcl-PHA thermal degradation were determined where degradation activation energy, Ed and pre-exponential factor, A equal to 85.3 kJ mol−1 and 6.07 × 105 s−1, respectively; and exhibited a negative activation entropy (∆S) of −139.4 J K−1 mol−1. Titration was carried out to determine the carboxylic terminal concentration and used to correlate number-average molecular weight (Mn) of the polymers. Thermally-degraded PHA contained higher amount of carboxylic terminals and lower Mn compared to the initial PHA and these results coincide with the decreased Mn in GPC analysis. Thermal properties of initial and degraded mcl-PHA were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermal decomposition mechanism was investigated following the analyses of the degradation products using 400-MHz 1H NMR, FTIR spectroscopy and GC analysis. The overall decomposition reaction is the hydrolysis of ester linkages to produce hydroxyl and carboxylic terminals. A small proportion of unsaturated side chain fragments would undergo oxidative cleavage at C
Biotechnology and Bioengineering, 2002
A novel and efficient method for the production of enantiomericaly pure R-3-hydroxyalkanoic acids and R-3-hydroxyalkanoic acid methylesters was developed. The described method is based on hydrolysis of poly(hydroxyalkanoate) copolymers synthesized by Pseudomonas putida. The polymer was isolated via solvent recovery and hydrolyzed by acid methanolysis. The obtained 3-hydroxyalkanoic acid methylester mixture was distilled into several fractions with an overall yield of 96.6% (w/w). Gas chromatography–mass spectrometry analysis of the fractions showed that 3-hydroxyhexanoic-, 3-hydroxyoctanoic-, 3 hydroxydecanoic-, and 3-hydroxydodecanoic acid methylesters were enriched to purities exceeding 96 mol%, with distillation yields of 99.9, 99.8, 88.4, and 56.8% (w/w), respectively. Subsequent saponification of the purified methylester fractions yielded the corresponding 3-hydroxyalkanoic acids, which were recovered up to 92.8% (w/w). Chiral gas chromatography analysis confirmed that both 3-hydroxyoctanoic acid and 3-hydroxyoctanoic acid methylester are present in the R-form at a very high enantiomeric excess (>99.9%). © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 717–722, 2002.
Overview on Polyhydroxyalkanoates: A Promising Biopol
Journal of Microbial & Biochemical Technology, 2011
Plastic pollution is creating the significant environmental and economic burdens since they consume the natural fuels (energy) and other natural resources. Beside this, they have long shelf time, debasing the environment in the numerous ways. The only way to trim down the hazards of plastic pollution is to decrease the use of plastic and thereby reducing its production. Degradations and recycling steps followed to diminish these plastic was of no use since it takes abundant stress (mechanical and chemical) to do so and also considered being costly. Biodegradable plastics became major approach to solve this issue and also became eminent since 1970s. From the inventory of biopolymers acting as bioplastics, PHA has gained major importance because of its analogous behavior to that of petro based plastics. PHAs are the linear polymers produced by the microbes to store energy and carbon. Present review discusses about the PHA production method, recent advances in producing, its degradation and applications of PHA which elucidates the gaining importance in today's industrial world.