Studies conducted by many workers in recent years have indicated substantial anisotropies in injection molded thermoplastics. These anisotropies have been associated with differences in morphology (crystallinity) and orientation (shrinkage and birefringences) at various positions in the molding. They are reflected by anisotropies in tensile properties measured at different points or in different directions. However, no work has been reported to quantitatively relate the distributions in tensile properties. The present work represents an attempt to meet this challenge. / Microstructure determination is achieved by making the following measurements on microtomed specimens at different positions in the polyethylene moldings: density, sonic speed, birefringence, wide-angle X-ray diffraction, dichroic ratio, and polarized light photomicrography. The above tests yield data relating to crystallinity and orientation functions for both the crystalline and amorphous phases. They also yield sufficient data to check the consistency of results obtained by the different techniques. Tensile properties are measured on microtomed samples obtained from the same regions tested for microstructure. Finally, the distributions of tensile and sonic moduli in the molding are estimated by employing some of the theoretical techniques proposed in the literature. The results show very good agreement between theoretical predictions and experimental data relating to the distributions of both sonic moduli and tensile moduli.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 194-209). Also available in electronic version.

Dissertation (PhD)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 104-110). Also available on the World Wide Web.

Thesis (M.S.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 106-107).

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xxi, 238 p.; also includes graphics Includes bibliographical references (p. 231-238). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xvi, 206 p.; also includes graphics (some col.). Includes bibliographical references (p. 167-173). Available online via OhioLINK's ETD Center

Thesis (M. Phil.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 174-176).

Thesis (M.S.)--Ohio State University, 2006. / Includes bibliographical references (leaf 111). Available online via OhioLINK's ETD Center

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (p. 89-102).