Effect of Molecular Weight on the Glass Transition Temperature of Conjugated Polymers

Open Access
Author:
Caggiano, Nicholas Joseph
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Enrique Gomez, Thesis Supervisor
  • Enrique Gomez, Honors Advisor
  • Michael Janik, Faculty Reader
Keywords:
  • Conjugated polymers
  • Glass transition
  • OPV
  • PFTBT
  • PCDTBT
  • Rheology
  • GPC
  • Polymer
  • Suzuki
Abstract:
Fully conjugated polymers, with their delocalized π networks, can serve as charge carriers in organic photovoltaic (OPV) devices. It is important to characterize the material properties of such polymers for future device fabrication. In this work the conjugated polymers PFTBT and PCDTBT were synthesized by a two-phase Suzuki polycondensation reaction. Molecular weight was varied by adjusting the monomer ratio during synthesis. Four batches of PFTBT and two batches of PCDTBT of varying weights were synthesized and characterized by GPC to obtain molecular weight. The glass transition temperature (Tg) was measured by a rheological temperature ramp study. Analysis shows that the glass transition temperature of the polymers increases with increasing molecular weight.