Poly-P-hydroxyvalerate

Braunegg G, Bogensberger B (1985) Zur Kinetik des Wachstums und der Speicherung von Poly-D(-)-3-hydroxybuttersaure bei Alcaligenes latus. Acta Biotechnol 5 339-345 Byrom D (1992) Production of poly-P-hydroxybutyrate poly-P-hydroxyvalerate copolymers. FEMS Microbiol Rev 103 247-250... 

Byrom D (1992) Production of poly-P-hydroxybutyrate and poly-p-hydroxyvalerate copolymers. FEMS Microbiol Rev 103 247-250... 

These techniques have been applied to PTFE [211,212], polybutadiene [213], rubbers [214, 215], acrylics [216,217], PE [218-220], polyurethane [221], PS [222], polyvinyl carbazole [223], polymalic acid [224], poly-P-hydroxybutyrate and poly-p-hydroxyvalerate [225], y-glycidoxy propyltrimethoxysilane [226], polypyrrole [227], and acrylonitrile-butadiene rubber [228]. 

Another example where metabolic pathway engineering has made a dramatic impact is in the biodegradable polymer field. The polymer of this family most widely studied is poly-P-hydroxybutyrate (PHB) (46). Another member of the PHA family commercialized by Imperial Chemical Industries (ICI), which later became Zeneca under the trade name Biopol, is a copolymer consisting of p-hydroxybutyric acid and P-hydroxyvaleric acid. This biodegradable polymer was first used in plastic shampoo bottles by the Wella Corporation [198]. In the early part of 1996, the Biopol product line, was purchased from Zeneca by the Monsanto Company. 

Isopropanolamine 2-Mercaptoethanol 1-Methyl-3-phenyl-5-[3-(trifluoromethyl) phenyi]-4(1 H)-pyridinone a-Naphthylamine Nitrosophenylhydroxylamine ammonium salt Phenyl benzoate m-Phenylenedimaleimide N-Phenylmaleimide Phenyl mercuric bromide Potassium carbonate Potassium N-hydroxymethyl-N-methyldithiocarbamate Pyridine Silica, fused Tetrachlorophthalic acid Thiourea p-Toluic acid , N-Tridecyl-2,6-dimethylmorpholine Trimethyl phosphate agric. chemicals, maleic hydrazide Hydrazine agric. sprays Zinc sulfate monohydrate agric., biodegradable Poly (hydroxybutyrate-hydroxyvalerate) agriculture... 

To date, various block copolymers have been produced using biological systems. This includes poly(3HB-fo-4HB) [17], P(3HB)-f>-poly(3-hydroxyvalerate-co-3-hydroxyheptanoate) [18], PHB-f -poly(hydroxyhexanoate) [19], poly 3HB-fc-poly(3-hydroxyheptanoate) [P(3HP)] [20], P(3HP)-f -poly(4-hydroxybutyrate) [P(4HB)] [21], poly(3-hydroxyhexanoate)-fe-poly(3-hydroxydecanoate)-co-[3-hydroxydodecanoate (3HDD)] [22] and poly[3-HDD-f -poly(3-hydroxy-9-decanoate)] [23]. These studies were motivated by the fact that although random copolymers, such as poly(3HB-co-3HV) and poly(3HB-co-4HB), exhibit useful mechanical and thermal properties they suffer from a deterioration of polymer properties due to the effect of ageing. It was found that all block copolymers exhibited improved properties compared with the two relative homopolymers, random and blend polymers. Various... 

Bloembergen S, Holden DA, Hamer GK, Bluhm TL, Marchessault RH (1986) Studies of composition and crystallinity of bacterial poly(P-hydroxybutyrate-co-P-hydroxyvalerate). Macromolecules 19 2865-2871... 

One potential area of application that has direct impact in polymer chemistry is the characterization of copolymers. The quantitative analysis of copolymer composition by MALDI has been demonstrated in a limited number of systems, though with varying degrees of success. For example. Abate et al showed that the relative amounts of hydroxybutyrate and hydroxyvalerate in a random copolymer, poly(P-hydroxybutyrate-co-P-hydroxyvalerate), when determined by MALDI, agree with those expected from theory [174]. Wilczek-Vera et al. have shown that for diblock... 

Biodegradable polymers can be classified into three categories according to their origin (i) synthetic polymers, particularly aUphatic polyesters, such as poly (L-lactide) (PLA) [1-3], poly(e-caprolactone) (PCL) [4—6], poly(p-dioxanone) (PPDO) [7-9], and poly(butylene succinate) (PBS) [10-12] (ii) polyesters produced by microorganisms, which mainly correspond to different poly(hydroxyalkanoate)s (e.g., poly(P-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate)) and (iii) polymers derived from natural resources (e.g., starch, cellulose, chitin, chitosan, lignin, and proteins). 

Davies,M.C.,Khan, M.A., Short,R.D.,Akhtar, S., Pouton, C., Watts, J.F. (1990) XPS and SSIMS analysis of the surface chemical structure of poly(caprolactone) and poly(P-hydroxybutyrate-P-hydroxyvalerate) copolymers. Biomaterials, 11,228-234. 

Journal of Microencapsulation 19, No.2, March/April 2002, p. 191-201 RELEASE OF DIAZEPAM FROM POLY(HYDROXYBUTYRATE-HYDROXYVALERATE) MICROSPHERES Chen J Davis S S... 

Polyhydroxyalkanoates (PHAs) such as poly(4-hydroxybutyric acid) (P(4HB)), poly(4-hydroxyvalerate) (P(4HV)), and their copolymers are bacterial polyesters synthesized by microbial fermentation. They have been described in detail in the earlier section on hydrolytically resorbable biopolymers. They are also found to be resorbable by enzymatic action in vivo. This particular family of bacterial polyesters is one of the most promising biomaterials currently under investigation. 

Until 2003, Chen s [28], Qu s [29-31], and Hu s [32] groups independently reported nanocomposites with polymeric matrices for the first time the. In Hsueh and Chen s work, exfoUated polyimide/LDH was prepared by in situ polymerization of a mixture of aminobenzoate-modified Mg-Al LDH and polyamic acid (polyimide precursor) in N,N-dimethylactamide [28]. In other work, Chen and Qu successfully synthesized exfoliated polyethylene-g-maleic anhydride (PE-g-MA)/LDH nanocomposites by refluxing in a nonpolar xylene solution of PE-g-MA [29,30]. Then, Li et al. prepared polyfmethyl methacrylate) (PMMA)/MgAl LDH by exfoliation/adsorption with acetone as cosolvent [32]. Since then, polymer/LDH nanocomposites have attracted extensive interest. The wide variety of polymers used for nanocomposite preparation include polyethylene (PE) [29, 30, 33 9], polystyrene (PS) [48, 50-58], poly(propylene carbonate) [59], poly(3-hydroxybutyrate) [60-62], poly(vinyl chloride) [63], syndiotactic polystyrene [64], polyurethane [65], poly[(3-hydroxybutyrate)-co-(3-hydroxyvalerate)] [66], polypropylene (PP) [48, 67-70], nylon 6 [9,71,72], ethylene vinyl acetate copolymer (EVA) [73-77], poly(L-lactide) [78], poly(ethylene terephthalate) [79, 80], poly(caprolactone) [81], poly(p-dioxanone) [82], poly(vinyl alcohol) [83], PMMA [32,47, 48, 57, 84-93], poly(2-hydroxyethyl methacrylate) [94], poly(styrene-co-methyl methacrylate) [95], polyimide [28], and epoxy [96-98]. These nanocomposites often exhibit enhanced mechanical, thermal, optical, and electrical properties and flame retardancy. Among them, the thermal properties and flame retardancy are the most interesting and will be discussed in the following sections. 

Li and co-workers [63] studied the crystallisation and melting behaviour of poly(]3-hydroxybutyrate (P-HB)-co-P-hydroxyvalerate (P-HV)) and a blend of poly(P-HB-co-P-HV)/polypropylene carbonate (30/70 w/w) using DSC and FT-IR spectroscopy. Transesterification occurred between poly(P-HB-co-P-HV) and polypropylene carbonate during the melt blending process. During crystallisation from the melt, the crystallisation temperature of the blend decreased by 8 °C compared with that of neat poly(P-HB-co-P-HV) and the melting temperature decreased by 4 °C. This indicated that the presence of polypropylene carbonate reduced the perfection of the poly(P-HB-co-P-HV) crystals, inhibited by the crystallisation of poly(p-HB-co-P-HV) and weakened its crystallisation ability. The equilibrium melting temperatures of... 

These include studies on reactions between polyacrylic acid and polymethacrylic acid, and polyacrylic acid with poly(4-vinyl pyridine) and poly(2-vinyl pyridene) [6], polybithiophene [7], poljwinyl carbazole sulfonation products [8], P-hydroxybutyrate and P-hydroxyvalerate containing Biopol [9]. 

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