Crystallization kinetics of polymer melts in extensional flow

A technique to study the kinetics of flow-induced crystallization of polymers in extensional flow has been developed which uses a 4-Roll Mill. The kinetics of a High Density Polyethylene were found to be well described by the Avrami treatment, indicated that the crystallization occurred by sporadic nucleation and one-dimensional growth and were a strong function of temperature and applied stress but were independent of strain history. The kinetics were found to be consistent with the Ziabicki theory for strain-induced crystallization but inconsistent with the theory of uttermost uniformity and an elevated melting point mechanism. The kinematics and stress fields of the 4-Roll Mill flow were measured independently by a tracer particle technique and an application of the Method of Isoclinics respectively allowing comparison to the predictions of several rheological equations of state. The deformation of a polymer droplet suspended in a carrier phase at low Reynolds number and high Weber number was documented. It is recommended that the 4-Roll Mill technique be used for study of other crystallizable polymer systems.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Tree, David Alan

Contributors dc:contributor

• McHugh, Anthony J.

• Engineering, Chemical

Statement dc:rights

• Copyright 1990 Tree, David Alan

Language dc:language

eng

Identifier

AAI9114443
(UMI)AAI9114443

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/19299