Structure and Property of Polybutylene, Polypropylene and Polyvinylidene Fluoride Crystallized From the Glassy State and Structure-Property - Processing Relationships of Polypropylene - Polybutylene Blends

Ultraquenching was used to obtain glassy polybutylene (PB), polypropylene (PP) and polyvinylidene fluoride (PVF(,2)). The structure and properties of the as-quenched and subsequently crystallized samples were characterized by various techniques. The glass has no structure larger than 30 (ANGSTROM). PB crystallizes from the glass into tetragonal structure (II) at ca. 0(DEGREES)C, depending on the sample thickness, then transforms to twinned hexagonal structure (I) upon aging at room temperature. In the presence of isopentane, PB crystallizes partially from the glass into untwinned hexagonal (I') structure at ca. -100(DEGREES)C, the rest of the sample transforms to tetragonal structure at ca. 0(DEGREES)C. The exact temperatures of both transformations depend on the amount of isopentane present and sample thickness. Upon aging at room temperature the tetragonal structure converts to twinned hexagonal structure even faster than in the absence of isopentane. Dynamic mechanical spectra show the presence of two relaxation-like peaks at -27(DEGREES)C and -15(DEGREES)C for the ultraquenched samples, presumably T(,g)(L) and T(,g)(U) respectively. X-ray diffraction, DSC and torsion pendulum show PB crystallizes from the glass at T(,g)(U).

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, Chih-Chung

• Chemistry, Polymer

Identifier

(UMI)AAI8422085

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71809