Deformation and Transformation Mechanisms of Polybutene and Poly(vinylidene Fluoride)

The deformation of thin films of polybutene (PB) and poly(vinylidene fluoride) (PVF$\sb2$) occurs by micronecking. Finite blocks are drawn off the edge of the microneck depending upon the orientation of the original crystalline lamellae comprising the spherulites with respect to the draw direction. Deformation of fresh PB thin film is accompanied by a transformation of tetragonal form to hexagonal form. Potassium permanganate etching and dark field microscopy of fresh thick and thin films reveal that the lateral crystal size of the tetragonal form crystals in the fresh film is significantly reduced upon transformation to the hexagonal crystals during aging. Dark field microscopy and electron diffraction patterns of the deformed PB thin films indicate that the majority of tetragonal crystalline segments transformed into the stable hexagonal crystals while still incorporated in the original lamellae, i.e. during tilt and slip of molecules within the blocks. Morphology of deformed thick films indicates the deformation behavior of thick films is more coherent than that of thin films.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Metallurgical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Hsu, Tsuey-Chen

Contributors dc:contributor

• Geil, Phillip H.

• Engineering, Materials Science

Identifier

(UMI)AAI8803070

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71847