טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentSuckeveriene Ran
SubjectDevelopment and Characterization of Nano-Composites Based on
Monomer Polymerization in the Presence of Nano-
Particles
DepartmentDepartment of Chemical Engineering
Supervisor Professor Emeritus Moshe Narkis
Full Thesis textFull thesis text - English Version


Abstract

This work describes a unique in-situ bulk polymerization method of styrene monomer in the presence of different types nano-particles (Al2O3, TiO2 and SiO2), different surfaces (hydrophobic, hydrophilic and methacrylic) with different particle sizes. Nano-particles were mixed with styrene solution containing different concentrations of initiator, followed by polymerization process for different periods and temperatures. In this peroxide bulk polymerization process two polystyrene fractions are formed: A polystyrene (PS) fraction attached to the particles surface, which cannot be detached by hot xylene extraction, and a free unattached PS fraction which dissolves in xylene. Solvent extraction along with TGA measurements have confirmed the existence of grafted PS chains to the nano-particle surfaces.

In the first part of this research various systems were investigated in order to find suitable conditions for the different particle types.

In the second part of this research nano-particles were melt-mixed as follows:

a.    With polypropylene matrix using batch processing in a Brabender Plastograph.

b.   With polypropylene matrix using continuous processing via a Brabender twin-screw extruder.

c.     With polystyrene matrix using continuous processing via a Brabender twin-screw extruder.

Research goals:

v  Development of a polymerization method of styrene in the presence of various types of nano-particles.

v  Prevent re-agglomeration of the nano-particles.

v  Fine dispersion of the nano-particles in the polymeric matrix.

v  Processing nano-particles/polymers using conventional processing methods.

v  Characterization of thermal and mechanical properties of the nano-composites.

v  Characterization and understanding the behavior of treated versus untreated nano-particles present in the polymeric matrix.