{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/19779"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/19779","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Characterization of thermoplastic J1 polymer and its graphite fiber AS4/J1 matrix composites","abstract":"The objectives of this research were to study, as a representative thermoplastic system: (1) the structure-property-thermal history relationships of the J1 matrix resin (DuPont, a semicrystalline polyamide) and AS4/J1 composites, and (2) the effect of moisture absorption on mechanical properties.","abstract_html":"The objectives of this research were to study, as a representative thermoplastic system: (1) the structure-property-thermal history relationships of the J1 matrix resin (DuPont, a semicrystalline polyamide) and AS4/J1 composites, and (2) the effect of moisture absorption on mechanical properties.","abstract_has_math":false,"creators":["Lin, David C."],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Materials Science and Engineering","degree_department":null,"school":null,"contributors":["Geil, Phillip H."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T12:18:16Z","date_published":"2011-05-07T12:18:16Z","updated_at":"2026-07-22T22:25:14Z","subjects":["Engineering, Chemical","Engineering, Materials Science"],"languages":["eng"],"rights":["Copyright 1991 Lin, David C."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9210896","(UMI)AAI9210896"],"render_values":[{"text":"AAI9210896","href":null,"code":true},{"text":"(UMI)AAI9210896","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/19779","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Geil, Phillip H."]},{"key":"dc:creator","label":"Author","values":["Lin, David C."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T12:18:16Z","10000-01-01","1991"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science and 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, Chemical","Engineering, Materials Science"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1991 Lin, David C."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9210896","(UMI)AAI9210896","http://hdl.handle.net/2142/19779"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The objectives of this research were to study, as a representative thermoplastic system: (1) the structure-property-thermal history relationships of the J1 matrix resin (DuPont, a semicrystalline polyamide) and AS4/J1 composites, and (2) the effect of moisture absorption on mechanical properties.","At least eight different kinds of crystal structures of J1 have been found; four of which are of significance in composite materials.","In-situ FTIR, DSC, and in-situ WAXD were used to study the crystal structure and thermal behavior of J1 as a function of temperature, thermal history and processing conditions. Two crystal-crystal transformations were observed in DSC and x-ray studies, a thermally reversible one at 145$\\sp\\circ$C and a thermally irreversible one at 240$\\sp\\circ$C. An endothermic peak seen in DSC scans at ca. 145$\\sp\\circ$C and multiple melting peaks between 265$\\sp\\circ$C and 285$\\sp\\circ$C are due to the reversible crystal-crystal transition and a crystal melting-recrystallization-remelting process respectively. Physical aging and dynamic mechanical spectroscopy studies were conducted to explore the superposition of the glass transition, T$\\sb{\\rm g}$, and the crystal-crystal transition at ca. 145$\\sp\\circ$C.","The effect of annealing (at temperatures between T$\\sb{\\rm g}$ and T$\\sb{\\rm m}$) on crystal structure, crystallinity, and properties of quenched(prepreg), and slow cooled(laminate) J1(AS4/J1) neat resin(composite) was investigated. The mechanical properties of J1 neat resin and unidirectional graphite fiber AS4/J1 laminates, with and without annealing at 240$\\sp\\circ$C for 8 hours, have been examined in tension, compression and three point bend tests. The processing history dependent differences in structure lead to significant differences in mechanical properties in both neat resin and composite.","The effect of moisture absorption on mechanical properties was also examined. The diffusion behavior of J1 resin and AS4/J1 composite obeys Fick's second law. The mechanical properties of water saturated melt crystallized J1 resin and (90) $\\sb{24}$ AS4/J1 laminates in tension show an increase in strain to failure and the same value of failure strength. A shear band deformation is seen in the water saturated J1 specimens in tensile tests; absorbed water molecules act as a plasticizer and soften the J1 resin. (Abstract shortened with permission of author.)","Made available in DSpace on 2011-05-07T12:18:16Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9210896.pdf: 8973330 bytes, checksum: 52967cff71590d012e7ff19a0196999d (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:39:22Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:16:33-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Characterization of thermoplastic J1 polymer and its graphite fiber AS4/J1 matrix composites"]}]}],"canonical_facts":{"dc:contributor":["Geil, Phillip H."],"dc:creator":["Lin, David C."],"dc:date":["2011-05-07T12:18:16Z","10000-01-01","1991"],"dc:description":["The objectives of this research were to study, as a representative thermoplastic system: (1) the structure-property-thermal history relationships of the J1 matrix resin (DuPont, a semicrystalline polyamide) and AS4/J1 composites, and (2) the effect of moisture absorption on mechanical properties.","At least eight different kinds of crystal structures of J1 have been found; four of which are of significance in composite materials.","In-situ FTIR, DSC, and in-situ WAXD were used to study the crystal structure and thermal behavior of J1 as a function of temperature, thermal history and processing conditions. Two crystal-crystal transformations were observed in DSC and x-ray studies, a thermally reversible one at 145$\\sp\\circ$C and a thermally irreversible one at 240$\\sp\\circ$C. An endothermic peak seen in DSC scans at ca. 145$\\sp\\circ$C and multiple melting peaks between 265$\\sp\\circ$C and 285$\\sp\\circ$C are due to the reversible crystal-crystal transition and a crystal melting-recrystallization-remelting process respectively. Physical aging and dynamic mechanical spectroscopy studies were conducted to explore the superposition of the glass transition, T$\\sb{\\rm g}$, and the crystal-crystal transition at ca. 145$\\sp\\circ$C.","The effect of annealing (at temperatures between T$\\sb{\\rm g}$ and T$\\sb{\\rm m}$) on crystal structure, crystallinity, and properties of quenched(prepreg), and slow cooled(laminate) J1(AS4/J1) neat resin(composite) was investigated. The mechanical properties of J1 neat resin and unidirectional graphite fiber AS4/J1 laminates, with and without annealing at 240$\\sp\\circ$C for 8 hours, have been examined in tension, compression and three point bend tests. The processing history dependent differences in structure lead to significant differences in mechanical properties in both neat resin and composite.","The effect of moisture absorption on mechanical properties was also examined. The diffusion behavior of J1 resin and AS4/J1 composite obeys Fick's second law. The mechanical properties of water saturated melt crystallized J1 resin and (90) $\\sb{24}$ AS4/J1 laminates in tension show an increase in strain to failure and the same value of failure strength. A shear band deformation is seen in the water saturated J1 specimens in tensile tests; absorbed water molecules act as a plasticizer and soften the J1 resin. (Abstract shortened with permission of author.)","Made available in DSpace on 2011-05-07T12:18:16Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9210896.pdf: 8973330 bytes, checksum: 52967cff71590d012e7ff19a0196999d (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:39:22Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:16:33-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9210896","(UMI)AAI9210896","http://hdl.handle.net/2142/19779"],"dc:language":["eng"],"dc:rights":["Copyright 1991 Lin, David C."],"dc:subject":["Engineering, Chemical","Engineering, Materials Science"],"dc:title":["Characterization of thermoplastic J1 polymer and its graphite fiber AS4/J1 matrix composites"],"dc:type":["text"],"thesis:degree_discipline":["Materials Science and Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:14Z"}