Poly .PHB

Reduction of the melting point by copolymerization is illustrated by the two systems shown in Figure 3, in which symmetrical polyesters are modified by copolymerization with parahydroxy-benzoic acid (PHB). In the case of poly(hydroquinone naphthalene-2, 6-dicarboxylate), its melting point is reduced from 580 C to about 325 C by copolymerization with 70% PHB. More PHB increases the melting point until it reaches 600 C for pure poly-PHB. ... 

Scattering experiments with synchroton radiation at A = 154 pm showed only small annealing effects proving the poor crystallizability of the COP the well known block structures of PET and PHB, however, were clearly identified (Figure 9.17). Pure poly-PHB is highly crystalline and shows a slight increase of the lattice distances with increasing temperature (thermal expansivity) with almost no additional crystallization. 

Reactions and Mechanisms in Thermal Analysis of Advanced Materials Table 7.1 Thermal parameters of poly(PHB/PCL-PEG-PCL urethane)s [20,66,73]. 

Poly-P-hydroxybutyrate (PHB) is a biodegradable thermoplastic that is produced by several microorganism. The PHB synthesis has been characterized eutrophus and the operon iavolved ia PHB productioa has beea cloaed. Recombiaant E. coli straias that can produce high levels of... 

Materials. Beside inorganic materials (eg, barium chloride/fluoride crystals, doped with 0.05% samarium), transparent thermoplasts are preferred for the PHB technique, eg, poly (methyl methacrylate) (PMAIA), polycarbonate, and polybutyral doped with small amounts of suitable organic dyes, organic pigments like phthalocyanines, 9-arninoacridine, 1,4-dihydroxyanthraquinone [81-64-1] (quinizarin) (1), and 2,3-dihydroporphyrin (chlorin) (2). 

New PHB materials are composed of Zn-tetraben2oporphyrin—aromatic cyanide—poly (methyl methacrylate) (180) or of tetraphenylporphyrin derivatives dispersed in polymer matrices such as PMMA and polyethylene (181). A survey of such materials has been given (181). 

PBT - polybutylene terephthalate PDMS - polydimethyl siloxane rubber PE - polyethylene PET - polyethylene terephthalate PHB - poly[D(-)]-3-hydroxy butyrate PP - polypropylene... 

PHB poly(3-hydroxybutanoic acid) PHBV poly(3-hydroxybutanoic acid-co-3-hydroxyvaleric acid), ref. 105. CCAPA poly(e-caprolactone) FB100, ref. 456. 

Phase-separated polymers, 215 Phase separation, 217-222 Phase transfer catalysts, 288, 563-564 Phase-transfer-catalyzed alkaline hydrolysis of nylon-4,6, 570 of nylon-6,6, 569-570 PHB. See Poly(3-hydroxybutanoic acid) (PHB)... 

Interestingly, it was in a different context that both Seebach and Gellman approached the field of yS-peptides. Seebach s initial interest in yS-peptides stemmed from their resemblance to poly(yS-hydroxy alkanoates) (PHA), an ubiquitous class of biopolymers of which poly[(P)-3-hydroxybutanoic acid] (8, PHB) is the most common (for reviews see [37, 38]). 

Bissery, M. C., Valeriote, F., and Thies, C., Fate and effect of CCNU-loaded microspheres made of poly(D,L) lactide (PLA) or poly B-hydroxybutyrate (PHB) in mice, Proc. Int. Symp. Control. Rel. Bioact. Mater.. 12. 181, 1985. 

Alcaligenes eutrophus produces a massive amount of intracellular polyester (poly-3-hydroxybutyrate [PHB]), specifically as high as 70% of the cell weight. This bacterium was selected for porous-media plugging studies [1316]. 

In our group, several dendrimers based on ( R)-3-hydroxybutanoic acid (HB) have been prepared [56-58]. The dendrimers were synthesized by the convergent strategy. Trimesic acid has been used as core unit and the benzyl esters of the dimer and the tetramer of HB as elongation units. In such a way dendrimers of 1st and 2nd generation (27-30) have been constructed (Fig. 13). Since poly(.R)-3-hydroxybutanoic acid (PHB) is known to be biodegradable [59, 60] the stability of the dendrimers 27-30 was tested in the presence of PHB-de-... 

R. eutropha PHB 4 phaC-x p 4HHp, 4HO Poly(3HB-co-3HHx-co-4HHx) [87] ... 

Poly(3-hydroxybutyrate), poly(3HB), or PHB is a bacterially produced polyester which appears in bacterial cells as discrete granules. The capability of synthesizing poly(3HB) is widespread in prokaryotes [1-3]. This capability is neither a taxon-related property nor an ecophysiological peculiarity. It is largely inde-... 

Poly(hydroxyalkanoates) (PHAs), of which poly(hydroxybutyrate) (PHB) is the most common, can be accumulated by a large number of bacteria as energy and carbon reserve. Due to their bio degradability and bio compatibility these optically active biopolyesters may find industrial applications. A general overview of the physical and material properties of PHAs, alongside with accomplished applications and new developments in this field is presented in this chapter. 

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