{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/71853"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/71853","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Strength Development at Incompatible Polymer Interfaces","abstract":"Mechanical strength of incompatible polymer interfaces welded above T$\\sb{\\rm g}$ has been investigated as a function of time, temperature, and composition. Three pairs of polymers were used: polystyrene-polymethylmethacrylate, polystyrene-co-acrylonitrile-polymethylmethacrylate, and polystyrene-co-acrylonitrile-polycarbonate. For each pair, the weld strength, as measured by G$\\sb{\\rm IC}$, attained a constant value which increased with welding temperature. While only five to ten percent of bulk G$\\sb{\\rm IC}$ values, these plateau values are orders of magnitude greater than the work of adhesion calculated using intermolecular forces. For the copolymer-homopolymer pairs, the maximum plateau strength was reached when the interaction parameter was a minimum. These results are in agreement with a model of the interface based on current molecular theories of incompatible interfaces coupled with a chain pull out microstructural deformation mechanism, which predicts that G$\\sb{\\rm IC}$ increases inversely with the interaction parameter, X. Microscopic investigation of the fracture surfaces revealed dissimilar fracture surfaces for a given pair, with evidence of stick-slip crack growth. X-ray photoelectron spectroscopy revealed residues of one polymer on the other's surface, indicating cohesive fracture occurred to some extent; in each case, the residue was always from the polymer with the lower entanglement density.","abstract_html":"Mechanical strength of incompatible polymer interfaces welded above T$\\sb{\\rm g}$ has been investigated as a function of time, temperature, and composition. Three pairs of polymers were used: polystyrene-polymethylmethacrylate, polystyrene-co-acrylonitrile-polymethylmethacrylate, and polystyrene-co-acrylonitrile-polycarbonate. For each pair, the weld strength, as measured by G$\\sb{\\rm IC}$, attained a constant value which increased with welding temperature. While only five to ten percent of bulk G$\\sb{\\rm IC}$ values, these plateau values are orders of magnitude greater than the work of adhesion calculated using intermolecular forces. For the copolymer-homopolymer pairs, the maximum plateau strength was reached when the interaction parameter was a minimum. These results are in agreement with a model of the interface based on current molecular theories of incompatible interfaces coupled with a chain pull out microstructural deformation mechanism, which predicts that G$\\sb{\\rm IC}$ increases inversely with the interaction parameter, X. Microscopic investigation of the fracture surfaces revealed dissimilar fracture surfaces for a given pair, with evidence of stick-slip crack growth. X-ray photoelectron spectroscopy revealed residues of one polymer on the other's surface, indicating cohesive fracture occurred to some extent; in each case, the residue was always from the polymer with the lower entanglement density.","abstract_has_math":true,"creators":["Willett, Julious Lee"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Metallurgical Engineering","degree_department":null,"school":null,"contributors":["Wool, Richard P."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-16T20:52:18Z","date_published":"2014-12-16T20:52:18Z","updated_at":"2026-07-22T22:26:05Z","subjects":["Engineering, Materials Science"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8823290"],"render_values":[{"text":"(UMI)AAI8823290","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/71853","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Wool, Richard P."]},{"key":"dc:creator","label":"Author","values":["Willett, Julious Lee"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-16T20:52:18Z","10000-01-01","1988"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Metallurgical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Materials Science"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/71853","(UMI)AAI8823290"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Mechanical strength of incompatible polymer interfaces welded above T$\\sb{\\rm g}$ has been investigated as a function of time, temperature, and composition. Three pairs of polymers were used: polystyrene-polymethylmethacrylate, polystyrene-co-acrylonitrile-polymethylmethacrylate, and polystyrene-co-acrylonitrile-polycarbonate. For each pair, the weld strength, as measured by G$\\sb{\\rm IC}$, attained a constant value which increased with welding temperature. While only five to ten percent of bulk G$\\sb{\\rm IC}$ values, these plateau values are orders of magnitude greater than the work of adhesion calculated using intermolecular forces. For the copolymer-homopolymer pairs, the maximum plateau strength was reached when the interaction parameter was a minimum. These results are in agreement with a model of the interface based on current molecular theories of incompatible interfaces coupled with a chain pull out microstructural deformation mechanism, which predicts that G$\\sb{\\rm IC}$ increases inversely with the interaction parameter, X. Microscopic investigation of the fracture surfaces revealed dissimilar fracture surfaces for a given pair, with evidence of stick-slip crack growth. X-ray photoelectron spectroscopy revealed residues of one polymer on the other's surface, indicating cohesive fracture occurred to some extent; in each case, the residue was always from the polymer with the lower entanglement density.","Made available in DSpace on 2014-12-16T20:52:18Z (GMT). No. of bitstreams: 1 8823290.pdf: 5113962 bytes, checksum: 87c04810974abd02dc1478a14f973517 (MD5) Previous issue date: 1988","Embargo set by: Seth Robbins for item 72019 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","221 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988."]},{"key":"dc:title","label":"Title","values":["Strength Development at Incompatible Polymer Interfaces"]}]}],"canonical_facts":{"dc:contributor":["Wool, Richard P."],"dc:creator":["Willett, Julious Lee"],"dc:date":["2014-12-16T20:52:18Z","10000-01-01","1988"],"dc:description":["Mechanical strength of incompatible polymer interfaces welded above T$\\sb{\\rm g}$ has been investigated as a function of time, temperature, and composition. Three pairs of polymers were used: polystyrene-polymethylmethacrylate, polystyrene-co-acrylonitrile-polymethylmethacrylate, and polystyrene-co-acrylonitrile-polycarbonate. For each pair, the weld strength, as measured by G$\\sb{\\rm IC}$, attained a constant value which increased with welding temperature. While only five to ten percent of bulk G$\\sb{\\rm IC}$ values, these plateau values are orders of magnitude greater than the work of adhesion calculated using intermolecular forces. For the copolymer-homopolymer pairs, the maximum plateau strength was reached when the interaction parameter was a minimum. These results are in agreement with a model of the interface based on current molecular theories of incompatible interfaces coupled with a chain pull out microstructural deformation mechanism, which predicts that G$\\sb{\\rm IC}$ increases inversely with the interaction parameter, X. Microscopic investigation of the fracture surfaces revealed dissimilar fracture surfaces for a given pair, with evidence of stick-slip crack growth. X-ray photoelectron spectroscopy revealed residues of one polymer on the other's surface, indicating cohesive fracture occurred to some extent; in each case, the residue was always from the polymer with the lower entanglement density.","Made available in DSpace on 2014-12-16T20:52:18Z (GMT). No. of bitstreams: 1 8823290.pdf: 5113962 bytes, checksum: 87c04810974abd02dc1478a14f973517 (MD5) Previous issue date: 1988","Embargo set by: Seth Robbins for item 72019 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","221 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988."],"dc:identifier":["http://hdl.handle.net/2142/71853","(UMI)AAI8823290"],"dc:subject":["Engineering, Materials Science"],"dc:title":["Strength Development at Incompatible Polymer Interfaces"],"dc:type":["text"],"thesis:degree_discipline":["Metallurgical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:05Z"}