Influence of the rubbery phase on the crystallinity and thermomechanical properties of poly(3-hydroxybutyrate)/elastomer blends
Résumé
Poly(3-hydroxybutyrate) (PHB) is a very promising biopolymer. In order to improve its processability and decrease its brittleness, PHB/elastomer blends can be prepared. In the work reported, the effect of the addition of a rubbery phase, i.e. ethylene-propylene-diene terpolymer (EPDM) or poly(vinyl butyral) (PVB), on the properties of PHB was studied. The effects of rubber type and of changing the PHB/elastomer blend processing method on the crystallinity and physical properties of the blends were also investigated. For blends based on PHB, the main role of EPDM is its nucleating effect evidenced by a decrease of crystallization temperature and an increase of crystallinity with increasing EPDM content regardless of the processing route. While EPDM has a weak effect on PHB glass transition temperature, PVB induces amarked decrease of this temperature thank to its plasticizer that swells the PHB amorphous phase. A promising solution to improve the mechanical properties of PHB seems to be the melt-processing of PHB with both plasticizer and EPDM. In fact, the plasticizer is more efficient than the elastomer in decreasing the PHB glass transition temperature and, because of the nucleating effect of EPDM, the decrease of the PHB modulus due to the plasticizer can be counterbalanced. © 2010 Society of Chemical Industry.
Mots clés
Amorphous phase
Crystallinities
Crystallization temperature
Ethylene propylene diene terpolymer
Melt processing
Nucleating effect
Poly(3-hydroxybutyrate)
Polyvinyl butyral
Processability
Processing method
Processing Route
Thermomechanical properties
Crystallization
Ethylene
Fracture mechanics
Glass
Mechanical properties
Plasticizers
Polymer blends
Processing
Propylene
Reinforced plastics
Rubber
Superconducting transition temperature
Glass transition
biopolymer
crystallinity
elastomer
glass transition temperature
mechanical property
nucleation
physical property
polymer blend
temperature
thermal property