Polyhydroxybutyrate composites

Lugscheider E, Knepper M, Gross KA (1992) Production of spherical apatite powders— The first step for optimized thermal-sprayed apatite coatings. J Thermal Spray Techn 1 215-223 Luklinska ZB, Bonfield W (1997) Morphology and ultrastractrrre of the interface between hydroxylapatite-polyhydroxybutyrate composite implant and bone. J Mater Sci Mater in Med 8 379-383 Lumbikanonda N, Sammons R (2001) Bone cell attachment to dental implants of different stuface characteristics. Inti J Oral Maxillofac Implants 16 627-636 Luo P, Nieh TG (1996) Preparing hydroxylapatite powders with controlled morphology. Biomaterials 17 1959-1964... 

Wang, M., Ni, J. and Wang, J. (2001) In vitro bioactivity and mechanical performance of tricalcium phosphate/ polyhydroxybutyrate composites Key Eng. Mater. Bioceramics, 14, 429-432. 

Figure 6. SEM photomicrographs of tensile fi acture surfaces of 40% cellulose-polyhydroxybutyrate composite.

Ni J, Wang M (2002) In vitro evaluation of hydroxyapatite reinforced polyhydroxybutyrate composite. Mater Sd Eng C20 101-109... 

Sunn hemp cellulose graft copolymers polyhydroxybutyrate composites morphological and mechanical studies. Adv. Mat. Lett., 2, 17—25. 

Medvecky, L., Stulajterova, R., Biiancin, J., 2007. Study of controlled tetracycline release from porous calcium phosphate/polyhydroxybutyrate composites. Chemical Papers 61, 477 84. 

Boeree, N.R., Dove, J., Cooper, J.J., Knowles, J. and Hastings, G.W. (1993) Development of a degradable composite for orthopaedic use mechanical evaluation of a hydroxyapatite-polyhydroxybutyrate composite material. Biomater. 14, 793-796. 

Metabolix s PHBV (polyhydroxybutyrate valerate) was initially developed by ICI. PHBV and related copolymers are made in a pilot plant using different bacteria to create compositions with up to 70% crystallinity. Elongation can be manipulated from 5% to 100%, and melting points range between 135 and 185 °C (275-365 °F). 

Abu Bakar et al. 1999), polyhydroxybutyrate (Luklinska and Bonfield 1997) and polysulfone (Wang et al. 2001). These composites are easily formed and are used in maxillofacial augmentation. More specific uses include nasal reconstruction (Lovice et al. 1999), middle ear reconstruction (Geyer 1999, Meijer et al. 2002) and repair of orbital fractures (Tanner et al. 1994). Recently, a pilot study has been conducted to examine the feasibility of thin sheets for the outer ear canal (Zanetti et al. 2001). The bone grows up to the composite and establishes a bond with the low resorbable HAp particles. 

Knowles, J., Hastings, G., Ohta, H., Niwa, S., Boeree, N. Development of a degradable composite for orthopaedic use in vivo biomechanical and histological evaluation of two bioactive degradable composites based on the polyhydroxybutyrate polymer. Biomaterials 13, 491 96 (1992)... 

It is known that PLA forms miscible blends with polymers such as PEG [53]. PLA and PEG are miscible with each other when the PLA fraction is below 50 per cent [53]. The PLA/PEG blend consists of two semi-miscible crystalline phases dispersed in an amorphous PLA matrix. PHB/PLA blends are miscible over the whole range of composition. The elastic modulus, stress at yield, and stress at break decrease, whereas the elongation at break increases, with increasing polyhydroxybutyrate (PHB) content [54]. Both PLA/PGA and PLA/PCL blends give immiscible components [55], the latter being susceptible to compatibilization with P(LA-co-CL) copolymers or other coupling agents. 

Barkoula, N.M., Garkhail, S.K., and Peijs, T. (2010) Biodegradable composites based on flax/polyhydroxybutyrate and its copolymer with hydroxyvalerate. Ind. Crops Prod., 31 (1), 34—42. 

Paskocimas, C.A. (2012) A biodegradable composite material based on polyhydroxybutyrate (PHB) and car-nauba fibers. Composites Part B, 43 (7), 2827-2835. 

Chiellini E, Solaro R (1996) Biodegradable polymeric materials. Adv Mater 8 305-313 Cyras VP, Commisso MS, Mauri AN et al (2007) Biodegradable double-layer films based on biological resources polyhydroxybutyrate and cellulose. J Appl Polym Sci 106 749-756 De Koning GJM (1993). Prospects of bacterial poly[(R)-3-hydroxyalkanoates]. Center for Polymers and Composites (CPC), Eindhoven University of Technology, Eindhoven Doi Y (1990) Microbial polyesters. Wiley, New York... 

Yasin, M. and B.J. Tighe, Strategies for the design of biodegradable polymer systems Manipulation of polyhydroxybutyrate-based materials, Plastics, Rubber and Composites Processing and Applications, 19 (199,3) 15-27. 

Polyhydroxybutyrate. Copolymers of hydroxybutyrate and hydroxyvaler-ate possess many mechanical properties in common with synthetic polyolefins, and so have attracted much attention as replacements for these materials in environments where biodegradability is an important parameter (see Poly(3-HYDROXYALKANOATES)). Carswell-Pomerantz and co-workers (217,218) have reported a detailed study of the radicals formed on irradiation of such materials. They found that the yield of radicals at 77 K was G(R) = 1.7 0.2, independent of copolymer composition, but that on irradiation at 300 K, the yield of radicals was reduced for the copol5mers because of their lower glass-transition temperatures compared with the homopolymer. At low temperatures a significant contribution to the ESR spectra from radical anions was noted. These radicals were observed to decay on warming to produce scission radicals. At still higher temperatures, radicals produced by abstraction of a methylene proton adjacent to the carbonyl group were detected. 

J.C. Knowles, F.A. Mahmud, G.W. Hastings, Piezoelectric characteristics of a polyhydroxybutyrate-based composite. Clinical Materials 8(1-2), 155-158 (1991)... 

The objective of the research was to prepare ultra-fine polymer composition fibers based on polyhydroxybutyrate and titanium dioxide and to determine the role played by nanosized titanium dioxide modifications in achieving special properties of the compositions. 

Natural biological composites, with cellulose as reinforcement and bacteria-produced polyhydroxybutyrate (PHB) as a matrix, were manufactured by compounding and injection molding. Such materials are totally biodegradable. 

Figure 6 shows an SEM micrograph of the tensile fracture surface of a composite containing 40% cellulose and polyhydroxybutyrate as a matrix. Among the observations are good adhesion, no debonding and fractured fibers. 

These materials are from renewable sources and are often made from plant materials that can be grown year after year and should come from agricultural nonfood crops. Biodegradable polymers are broken down into CO 2 and water by microorganisms. Although biopolymers may be able to help solve the disposal problems of current plastic packaging, it is not clear if they can really deliver on this promise and whether there is possible competition with the food chain. Cellulose is the most common biopolymer and organic compound on Earth. Other examples are starch, PHB (polyhydroxybutyrate), natural fibers, silk, and wood plastic composites (WPC). 

Tg measurements have been performed on many other polymers and copolymers including phenol bark resins [71], PS [72-74], p-nitrobenzene substituted polymethacrylates [75], PC [76], polyimines [77], polyurethanes (PU) [78], Novolac resins [71], polyisoprene, polybutadiene, polychloroprene, nitrile rubber, ethylene-propylene-diene terpolymer and butyl rubber [79], bisphenol-A epoxy diacrylate-trimethylolpropane triacrylate [80], mono and dipolyphosphazenes [81], polyethylene glycol-polylactic acid entrapment polymers [82], polyether nitrile copolymers [83], polyacrylate-polyoxyethylene grafts [84], Novolak type thermosets [71], polyester carbonates [85], polyethylene naphthalene, 2,6, dicarboxylate [86], PET-polyethylene 2,6-naphthalone carboxylate blends [87], a-phenyl substituted aromatic-aliphatic polyamides [88], sodium acrylate-methyl methacrylate multiblock copolymers [89], telechelic sulfonate polyester ionomers [90], aromatic polyamides [91], polyimides [91], 4,4"-bis(4-oxyphenoxy)benzophenone diglycidyl ether - 3,4 epoxycyclohexyl methyl 3,4 epoxy cyclohexane carboxylate blends [92], PET [93], polyhydroxybutyrate [94], polyetherimides [95], macrocyclic aromatic disulfide oligomers [96], acrylics [97], PU urea elastomers [97], glass reinforced epoxy resin composites [98], PVOH [99], polymethyl methacrylate-N-phenyl maleimide, styrene copolymers [100], chiral... 

Nanocomposites examined include PP/PP - styrene - butadiene [95], PA - clay [96], dicyanate - clay [97, 98], polypropylene carbon [99], and the following composites polyfuran/poly(2-fluoroaniline) [100], polyvinyl alcohol - cadmium sulfide [100, 101], polyhydroxybutyrate - polyvinyl alcohol (PVOH) [102], HOPE - wood flour [103], polyaniline - gold [104] and PU - casein [105]. 

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