Viscoelastic and molecular weight effect on phase separation in PEI modified epoxy blends

POLY 192

Wenjun Gan, ganwj@sh163.net, College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, No.333 Longteng Road, Shanghai, 201620, China, Yingfeng Yu, Department of Macromolecular Science and The Key Laboratory of Molecular Engineering of Polymer, Ministry of Education, Fudan University, No.220 Handan Road, Shanghai, 200433, China, and Shanjun Li, sjli@fudan.edu.cn, Department of macromolecular Science and Laboratory of Macromolecular Engineering of Polymers, Fudan University, No.220 Handan Road, Shanghai, 200433, China.
Phase separations for epoxy/PEI/anhydride blends with different molecular weight of PEI were investigated by time-resolved light scattering (TRLS), and scanning electron microscopy (SEM) at different curing temperatures. The morphologies at different temperature are almost same and close to co-continuous structure. The results of TRLS indicate that phase separation for PEI modified epoxy resin blends takes place according to the spinodal decomposition mechanism. The time dependent qm was simulated according to the Maxwell-type relaxation equation and the obtained relaxation times at different temperatures were fit with the Williams-Landel-Ferry equation. It is found that the evolution of scattering vector qm follows the viscoelastic relaxation model. Meanwhile as the molecular weight of PEI decreases, phase separation takes place latter and bigger periodic distance results.
 

General Papers: Functional Materials
6:00 PM-8:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Polymer Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007