Poly(hydroxybutyrate-Co-Hydroxyvalerate) Micronization by Solution Enhanced Dispersion by Supercritical Fluids Technique

Abstract

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a biodegradable polymer used for a wide range of applications, especially in biomedical and food industry, for which bioactive compound encapsulation is noteworthy. This work aimed to micronize PHBV by Solution Enhanced Dispersion by Supercritical Fluids technique and evaluate possible changes in polymer crystallinity. A 2 3 Central Composite Design with 3 central points was used to analyze the influence of pressure, temperature and PHBV concentration on particle size produced. Micronized particles were mostly spherical with sizes from 210 to 720 nm, and free of organic solvents. PHBV crystallinity degree was approximately 20% higher when polymer was processed at 8 MPa compared to that processed at 10 and 12 MPa, as well as to the raw polymer. Results suggest versatility in PHBV application according to SEDS process parameters and the possibility of its use in drug delivery systems.

Effect of 3-Hydroxyvalerate Content on Thermal, Mechanical, and Rheological Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Biopolymers Produced from Fermented Dairy Manure

“…Purified PHBV samples were analyzed by FTIR spectroscopy to gain insight into its chemical structure; results are given in Table 3 . The C–C stretching band occurs at 977 cm −1 [ 38 , 39 ]. The C–O stretching bands are observed between 1054 and 1129 cm −1 and from 1226 to 1275 cm −1 [ 38 , 39 , 40 , 41 ].…”

“…The C–C stretching band occurs at 977 cm −1 [ 38 , 39 ]. The C–O stretching bands are observed between 1054 and 1129 cm −1 and from 1226 to 1275 cm −1 [ 38 , 39 , 40 , 41 ]. The band at 1179 cm −1 was assigned to the C–O–C stretching of the amorphous PHBV [ 42 ].…”

“…The band at 1720 cm −1 (highest intensity) was assigned to a C=O stretching of an ester structure in PHBV [ 6 , 38 , 40 ]. The C–H stretching bands of methyl (–CH 3 ) and methylene (–CH 2 ) groups appeared at 2975 cm −1 and 2933 cm −1 , respectively [ 39 , 40 , 43 ]. Analysis of the FTIR spectra can be used to gain insight into the relative amounts of amorphous versus crystalline material in PHBV by determining the carbonyl index ( I C= O ).…”

Green Composites from a Bioplastic Blend of Poly(3-hyroxybutyrate-co-3-hydroxyvalerate) and Carbon Dioxide-Derived Poly(propylene carbonate) and Filled with a Corn Ethanol-Industry Co-product

“…However, despite this potential asset, PHAs are relatively expensive compared to other commercial plastics with comparable properties, and the costs increase with greater complexity in the PHA family. Furthermore, PHBV has a narrow processing window and inferior mechanical properties (i.e., highly brittle), making it unsuitable for various applications such as biomedical and flexible packaging. − …”

Formation of Polymer-Carbon Nanotube Composites by Two-Step Supercritical Fluid Treatment

“…Subsequent flushing of the precipitation chamber with an additional portion of the SCF allows rinsing the precipitated product from the traces of organic solvents. SAS is widely used for micronization of pharmaceutical substances [ 37 , 38 , 39 , 40 , 41 ], biocompatible polymers [ 42 , 43 , 44 ], formation of catalysts [ 45 , 46 ], superconductor precursor nanoparticles [ 47 ], explosives and high propellants [ 48 ], etc. The main advantage of the SAS process for preparation of CNT-polymer composites is very fast solute precipitation.…”