Thermal properties and crystallization behavior of poly(3-hydroxybutyric acid) in blends with chitin and chitosan

Abstract

SUMMARY: Films of blends of microbial poly(3-hydroxybutyric acid) (PHB) with a-chitin and chitosan were prepared as completely biodegradable polyester-polysaccharide composites. DSC revealed that the crystallization of PHB in these blends is suppressed when the proportion of the polysaccharide is increased. The same tendency was evident from the FT-IR band intensity of the carbonyl stretching absorption from PHB. Chitosan was found to have a stronger ability to suppress the crystallization of PHB than a-chitin. PHB in the blends was found by 13 C NMR spectroscopy to be trapped in the 'glassy' environment of the polysaccharide. Upon blending with PHB, the chitosan resonances are significantly broadend as compared to the chitin resonances. Hydrogen bonds are suggested to be formed between the carbonyl groups of PHB and the amide NH groups of chitin and chitosan.

Production and characterization of bacterial polyhydroxyalkanoate copolymers and evaluation of their blends by fourier transform infrared spectroscopy and scanning electron microscopy

“…PHA has been blended earlier with chitosan, starch, laprol, PEG etc. to produce fi lm of better mechanical property [5,16,17]. In the present study, PHA obtained from R. meliloti, which contained 3 mol% of HV and PHA from recombinant E. coli, which contained scl-co-mcl PHA (71:29 mol%) were used for blending.…”

“…Major band shift was noticed in C=O regions for the blends. Suppression of crystallinity is assigned to the formation of intermolecular hydrogen bonds between PHA carbonyls and the blend substrate used [17]. This is also evidenced by the FTIR band intensity of the carbonyl stretching absorption from PHA and its blends using PVAc as a plasticizer (Tables 2 and 3).…”

“…This is also evidenced by the FTIR band intensity of the carbonyl stretching absorption from PHA and its blends using PVAc as a plasticizer (Tables 2 and 3). The lowest band (1724 cm -1 ) is assigned due to crystalline phase and stronger absorption bands at 1735, 1743 cm -1 are attributed to amorphous phase [17].…”

Properties of Powder Composite Polyhydroxybutyrate–Chitosan-Calcium Phosphate System

“…In FTIR spectra of the composite before and after 7 days of setting in SBF, the band at wavenumber of 1721 cm -1 characterizes C=O stretching vibration [22] of PHB and bands at 1631 and 1555 cm -1 partially overlapped with the bending vibrations of physically adsorbed water (at around 1650 cm -1 ) can be assigned to the chitosan amide I C=O vibrations and the imide II N-H deformation vibrations respectively [23,24].…”

Miscibility and Physical Properties of Poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)/Poly(ethylene oxide) Binary Blends

“…[2][3][4] Efforts have been devoted to blending P(3HB) with suitable polymers, and this is expected to improve its impact strength and thermal properties. [5][6][7][8] Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] is one of the bacterial P(3HB) copolymers, [9][10][11] which exhibits significantly improved physical properties than those of P(3HB) due to the long side chain. The physical properties of P(3HB-co-3HHx) have been intensively studied and described in several previous Full Paper In order to improve some inferior physical properties of bacterial poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] by blending with PEO, the miscibility, spherulite morphology, crystallization behavior and mechanical properties of P(3HB-co-3HHx)/PEO binary biodegradable polymer blends were investigated.…”