Crystallization and melting behaviour of PHB and PHB/HV copolymer

Properties of melt-processed poly(hydroxybutyrate-co-hydroxyvalerate)/starch 1:1 blend nanocomposites

“…An excess of a carbon source and limiting concentrations of essential nutrients are required for their production. Poly(3-hydroxybutyrate) (PHB) and the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) are produced commercially, but their high melting point (>170º), high crystallinity and brittleness, and a narrow processing window, hinder their practical application [3][4][5] . Improved properties have been achieved for PHA copolymers of 3-hydroxybutyrate and other medium-chain length 3-hydroxyalcanoate comonomers.…”

Morphology and thermal properties of biodegradable poly(hydroxybutyrate-co-hydroxyvalerate)/tungsten disulphide inorganic nanotube nanocomposites

“…9 presents representative WAXS diffractograms obtained dur ing crystallization and subsequent melting for neat PHBV and a nanocomposite with 1.0 wt.% INT WS 2 . For both the neat PHBV and the PHBV/INT WS 2 (1.0 wt.%) samples it can be seen that the crystalline structure developed was identical, with diffraction peaks at 2q 13.4 , 16.8 , 20.1 , 21.5 , 22.5 , 25.5 , 27.2 , the first two being the most intense corresponding to planes (020) and (110), in respective order, characteristic of orthorhombic PHBV crystalline a type structure [8,50]. The nanocomposite sample presented an additional diffraction peak at 14.2 , which corre sponds to the (002) plane of the inorganic nanotubes [30].…”

The effect of copolymer composition on the spatial structural hierarchy developed in injection molded bacterial poly(3-hydroxybutyrate-co-3-hydroxyvalerate) parts

“…In their study, the incorporation of a small fraction of HV in the HB crystals where they act as defects without influencing the lattice spacing also was not ruled out. In addition, Owen et al [29] research indicated that the higher melting peak corresponds to those crystals that are more perfect devoid of HV defects and the lower melting peaks are very much controlled by other conditions such as heating rate. They proposed two mechanisms for the existence of lower melting peak.…”

“…These polymers are generally crystallizable [6][7][8][9][10][11], and copolymerization with hydroxy valerate suppresses the crystal growth rates [12][13][14][15][16][17][18][19][20] and commercial grades typically contain nucleating agent (eg. boron nitride) to accelerate the crystallization process.…”