Direct Observations of Three Nucleation/Growth Processes of Charge-Stabilized Dispersion Polymerizations with Varying Water/Methanol Ratios

作者：Zhang, Fen; Ma, Yuhong; Liu, Lianying; Yang, Wantai^*

来源：Journal of Physical Chemistry B, 2010, 114(34): 10970-10978.

DOI：10.1021/jp102936n

• POLY(ETHYLENE OXIDE) MACROMONOMERS
• ETHANOL-WATER MEDIA
• PARTICLE-SIZE
• METHYL-METHACRYLATE
• POLAR-SOLVENTS
• POLYSTYRENE PARTICLES
• POLYMER PARTICLES
• MICROMETER-SIZE
• STYRENE
• MONODISPERSE

This article presents observations of three polymerization modes of a self-developed cation-charge-stabilized styrene/water/methanol dispersion polymerization system: (1) a water/methanol (20/80) system, corresponding to a typical dispersion polymerization mode where the particle nucleation occurred in the solution phase and growth in the particle phase; (2) a pure CH3OH system, including a first nucleation in the solution phase with growth by absorption of the small particles and polymers formed in this phase, and a secondary nucleation with growth in the particle phase, when high molecular weight copolymers appeared in the solution phase; and (3) a water/methanol (5/95) system, similar to the conventional dispersion polymerization mode during the first 90 min, with subsequent epitaxial growth. Interestingly, the metastable state of the nucleation stage, including minuscule 6-nm particles, their aggregates, and the aggregating process, was first observed experimentally. By quantitatively following the relationship of the deposited molecular weight and the nucleation/growth process in the three systems, it was proposed that the molecular weight of the deposited polymer had to reach a specific high value before they could absorb or capture monomer to form smooth/spherical nuclei or particles.

• 出版日期2010-9-2
• 单位北京化工大学