Flow-Induced Crystallization of Poly- (Ethylene Oxide)

Open Access
Author:
Mack, Audrey
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Ralph H Colby, Thesis Supervisor
  • Scott Thomas Milner, Honors Advisor
Keywords:
  • Rheology
  • Crystallization
  • Rheometry
  • Flow-Induced Crystallization
  • Poly (Ethylene Oxide)
  • PEO
Abstract:
The purpose of this research is to study the flow-induced crystallization of poly- (ethylene oxide) of different molecular weights using rotational rheometry. Experiments were carried out to determine the behavior of the material in the melt state, specifically as functions of frequency and shear rate. The quiescent crystallization behavior of PEO was studied, and the impact of flow on this crystallization behavior was explored in detail. The goal of this work was to establish the criteria for the onset of flow-induced crystallization, to determine if a point exists when the increased rate of crystallization will begin to level off or decrease (saturation point) in PEOs with different molecular weights and molecular weight distributions, and to determine the governing parameter of FIC in PEO. Parameters that were considered include shearing time, shearing rate, shearing temperature and specific work applied. The strengths of FIC effects were compared to the fraction of stretchable chains in the molecular weight distributions.