writer：Jianxiang Chen, Defeng Wu,* Keren Pan
keywords：ethyl cellulose (EC); poly( -hydroxybutyrate) (PHB); blends; spherulite; properties.
source：期刊
specific source：International Journal of Biological Macromolecules
Issue time：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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http://www.sciencedirect.com/science/article/pii/S0141813016302720