Title of article :
Nascent morphology of syndiotactic polystyrene synthesized over silica-supported metallocene catalyst
Author/Authors :
Han، نويسنده , , Joong Jin and Yoon، نويسنده , , Won Jung and Lee، نويسنده , , Hyung Woo and Choi، نويسنده , , Kyu Yong، نويسنده ,
Issue Information :
دوهفته نامه با شماره پیاپی سال 2008
Abstract :
The nascent morphology of semi-crystalline syndiotactic polystyrene (sPS) polymerized over silica-supported pentamethyl cyclopentadienyl titanium trimethoxide (Cp∗Ti(OCH3)3) catalyst in a liquid slurry polymerization has been investigated under various reaction conditions. The scanning electron microscopic analysis of nascent polymers reveals that sPS molecules grow as long nanofibrils of 30–50 nm diameter and X-ray diffraction analysis shows the co-crystalline phases including both sPS and low molecular weight guest molecules of monomer and diluent. The energy dispersive X-ray spectroscopy also shows that the disintegration of silica primary particles occurs during the polymerization as evidenced by the uniform dispersion of silicon and aluminum in a polymer particle. The fibrous growth of the polymer inside a polymer particle leads to the shape replication of the original silica particles.
Keywords :
Syndiotactic polystyrene , Polymer morphology , crystallization