Study of the behavior of blends of a poly(hydroxybutyrate‐valerate) copolymer, polypropylene, and SEBS

Abstract

Polyhydroxyalkanoates are a type of polymers with a clear renewable origin, as different types of microorganisms can produce them. Unfortunately, their mechanical properties are not usually as good as those of conventional polymers and for a moment their price is relatively higher; these are two of the reasons why it is suggested in the bibliography that they can be employed forming part of blends with conventional polymers. In the present work, blends of a poly(hydroxybutyrate-valerate) (PHBV) copolymer and a polypropylene resin have been successfully processed using PHBV concentrations up to 20 phr with internal mixer and a hot plate press. Processability and applicability of such blends logically depend on their properties, and for this reason morphology, rheological, thermal properties, and tensile strength for all samples have been evaluated. Ternary blends, incorporating a poly(styrene-ethylene-butylene) copolymer have also been obtained and the influence of the blends properties has been analyzed. Results have shown that the rheological behavior and crystallization process of the system is markedly dependent on the blend composition. Although tensile strength significantly decreases with PHBV concentration, the use of low concentrations of the styrene-ethylene-butylene-styrene copolymer could improve the elongation at break to a certain extent.

Polylactide/poly(hydroxybutyrate-co-hydroxyvalerate) blends: Morphology and mechanical properties

“…Its properties are known to depend on hydroxyvalerate (HV) content [10]. At very low HV content, PHBV is similar to conventional petrochemical thermoplastics, such as polypropylene, in terms of melting temperature, crystallinity, and tensile strength [11][12][13][14][15]. Most of literature agrees on immiscibility of PLA and PHBV [16][17][18][19].…”

Prodegradant effect of titanium dioxide nanoparticulates on polypropylene–polyhydroxybutyrate blends

“…One of the methods that has been investigated as a partial solution for reducing the impact of polyolefins in the environment is their mixture with biodegradable polymers. Some authors have investigated the behavior of polymeric blends based on poly(hydroxybutyrate) (PHB) or poly(hydroxybutyrate–valerate) and PP . This combination of polymers is favored because of the similarity of their thermal properties, such as their melting points, which is desirable when materials are produced through thermal processing .…”

Fabrication and improved performance of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) for packaging by addition of high molecular weight natural rubber

“…Bacteria and enzymes can degrade aliphatic polymers with hydrolyzable carbon backbones, such as bacterially synthesized poly(3‐hydroxybutyrate) (PHB), thus alleviating landfill saturation . PHB is produced by nutrient‐deprived microorganisms, which accumulate the polymer as an intracellular form of energy storage . However, commercial use of PHB is limited due to thermal degradation, and brittleness at room temperature, in addition to its higher production costs.…”

“…PHB is produced by nutrient‐deprived microorganisms, which accumulate the polymer as an intracellular form of energy storage . However, commercial use of PHB is limited due to thermal degradation, and brittleness at room temperature, in addition to its higher production costs. During the growth stage of PHB homopolymer, incorporation of propionic or pentanoic acid, while restricting dissolved oxygen, leads to the formation of 3‐hydroxyvalerate (PHV).…”