DC Field | Value | Language |
---|---|---|
dc.contributor.author | Kim, SI | - |
dc.contributor.author | Pyo, SM | - |
dc.contributor.author | Ree, M | - |
dc.date.accessioned | 2016-03-31T13:58:24Z | - |
dc.date.available | 2016-03-31T13:58:24Z | - |
dc.date.created | 2009-03-09 | - |
dc.date.issued | 1997-12-15 | - |
dc.identifier.issn | 0024-9297 | - |
dc.identifier.other | 1998-OAK-0000000010 | - |
dc.identifier.uri | https://oasis.postech.ac.kr/handle/2014.oak/20928 | - |
dc.description.abstract | Aromatic poly(amic acid) precursors always form complexes with dipolar aprotic solvents via strong acid/base interaction and are expected to have relatively high glass transition temperatures (T-g's) which are overlapped with or higher than the imidization temperatures, so that their T-g's could not he determined in spite of their wide usages. In the present study, the measurement of T-g was attempted fur poly(amic acid) precursors of three different aromatic polyimides synthesized in N-methyl-2-pyrrolidone (NMP) from the respective dianhydrides and diamines: poly(4,4'-oxydiphenylene pyromellitamic acid) (PMDA-ODA), poly(p-phenylene 3,3',4,4'-oxydiphthalamic acid) (ODPA-PDA), and poly(p-phenylene benzophenonetetracarboxamic acid) (BTDA-PDA). Phase transitions, as well as imidization reactions in the precursor/NMP mixtures, were measured with varying compositions by a newly developed oscillating differential scanning calorimetry Compositions in the mixtures were determined by proton nuclear magnetic resonance spectroscopy. For solvent-rich mixtures, a melting point depression of the NMP solvent was observed, whereas for precursor rich mixtures, T-g depression was detected. In particular, T-g's measured for the precursor rich mixtures were best fitted by a modified Gordon-Taylor equation as a function of composition, in order to estimate T(g)s of poly(amic acid)s in solvent free, that is, true T-g's of the precursor polymers: 207.4 degrees C for PMDA-ODA, 166.3 degrees C for ODPA-PDA, and 213.2 degrees C for BTDA-PDA precursor. The Kuhn segment length, which is a measure of chain flexibility, was estimated to be 43.3 Angstrom for PMDA-ODA, 34.6 Angstrom for ODPA-PDA, and 34.6 Angstrom for BTDA-PDA. In addition, a phase diagram was constructed Cor the PMDA-ODA precursor/NMP mixture. For the highly dried precursor samples, the chemical repeat unit, was also determined to complex with 1.4-1.7 NMP molecules, depending on the precursors. | - |
dc.description.statementofresponsibility | X | - |
dc.language | English | - |
dc.publisher | AMER CHEMICAL SOC | - |
dc.relation.isPartOf | MACROMOLECULES | - |
dc.subject | FLEXIBILITY | - |
dc.subject | SCATTERING | - |
dc.subject | BLENDS | - |
dc.subject | IR | - |
dc.title | Investigation of glass transition behaviors in poly(amic acid) precursors of semiflexible polyimides by oscillating differential scanning calorimetry | - |
dc.type | Article | - |
dc.contributor.college | BK분자과학사업단 | - |
dc.identifier.doi | 10.1021/ma970556f | - |
dc.author.google | Kim, SI | - |
dc.author.google | Pyo, SM | - |
dc.author.google | Ree, M | - |
dc.relation.volume | 30 | - |
dc.relation.issue | 25 | - |
dc.relation.startpage | 7890 | - |
dc.relation.lastpage | 7897 | - |
dc.contributor.id | 10115761 | - |
dc.relation.journal | MACROMOLECULES | - |
dc.relation.index | SCI급, SCOPUS 등재논문 | - |
dc.relation.sci | SCI | - |
dc.collections.name | Journal Papers | - |
dc.type.rims | ART | - |
dc.identifier.bibliographicCitation | MACROMOLECULES, v.30, no.25, pp.7890 - 7897 | - |
dc.identifier.wosid | 000071057600036 | - |
dc.date.tcdate | 2019-01-01 | - |
dc.citation.endPage | 7897 | - |
dc.citation.number | 25 | - |
dc.citation.startPage | 7890 | - |
dc.citation.title | MACROMOLECULES | - |
dc.citation.volume | 30 | - |
dc.contributor.affiliatedAuthor | Ree, M | - |
dc.identifier.scopusid | 2-s2.0-0031338978 | - |
dc.description.journalClass | 1 | - |
dc.description.journalClass | 1 | - |
dc.description.wostc | 35 | - |
dc.type.docType | Article | - |
dc.subject.keywordPlus | FLEXIBILITY | - |
dc.subject.keywordPlus | SCATTERING | - |
dc.subject.keywordPlus | BLENDS | - |
dc.subject.keywordPlus | IR | - |
dc.relation.journalWebOfScienceCategory | Polymer Science | - |
dc.description.journalRegisteredClass | scie | - |
dc.description.journalRegisteredClass | scopus | - |
dc.relation.journalResearchArea | Polymer Science | - |
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