Effects of Ethyl Cellulose on the Crystallization and Mechanical Properties of Poly(β-hydroxybutyrate)
作者：Jianxiang Chen, Defeng Wu,* Keren Pan
關(guān)鍵字：ethyl cellulose (EC); poly( -hydroxybutyrate) (PHB); blends; spherulite; properties.
論文來源：期刊
具體來源：International Journal of Biological Macromolecules
發(fā)表時間：2016年
International Journal of Biological Macromolecules, 2016,88C, 120-129.
ABSTRACT:
Ethyl
cellulose (EC) was blended with poly(β-hydroxybutyrate)
(PHB), aiming at controlling crystallization and mechanical properties of PHB. The obtained PHB/EC blend is an immiscible system,
and the discrete EC phase behaves dual characteristics in the PHB matrix, as
the viscoelastic droplets during processing, and as the rigid filler particles during
shear flow. This is confirmed by the rheological
tests. The presence of EC domains acts as the tackifier, sharply increasing system viscosity from 1,000 Pa?s to 5,000 Pa?s,
and as a result, has large influence on the spherulite morphology of PHB and its crystallization
kinetics. The PHB spherulite growth rate reduces in the presence of
inert EC, accompanied by decreased degree
of crystallinity and reduced lamella defects. These
affect the mechanical properties of PHB strongly, together with reinforcing
effect of EC itself. At the lower content level,
EC can act as both reinforcement and toughener. The presence of 1 wt% EC enhances the tensile
strength of PHB by about 22%, from 27.5 MPa to 33.3 MPa, accompanied by 15%
increase of impact strength. This work provide an easy
way to control the structure and properties of PHB using EC.
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