{"id":{"repo_id":"cent-lancashire","oai_identifier":"oai:clok.uclan.ac.uk:20704"},"canonical_url":"https://search.dev.ndltd.org/etd/cent-lancashire/oai:clok.uclan.ac.uk:20704","repository":{"repo_id":"cent-lancashire","name":"University of Central Lancashire","base_url":"https://clok.uclan.ac.uk/cgi/oai2"},"display":{"title":"The crystal stucture determination of low and high temperature phases of Tris (Ethylene Terephthalate)","abstract":"Tris (Ethylene Terephthalate) is an oligomer of Polyethylene Terephthalate with a chemical formula of -[O.00.C 6H 4 .CO.O.CH2 .CHJ 3 -. It has two phases, namely the Low Temperature phase (Type A) which isstable below 801C; and the High Temperature Phase (Type B) - stable between 800C and its melting temperature 320 0C. The crystal structures of these two phases have been determined by X-ray diffraction of single crystals. The LTP crystals were crystallised from its solution in DMF at room temperature. The LTP crstals were found to have a monoclinic unit cell and spac%C; the unit cell is a = 16.98A°, b = 19.59A °, c = 8.43A and $ 96.240 with z = 4 molecules/unit cell; d(obs) = 1.367 g/cm 3 . The HTP trimer crystals were formed from a hot solution of tris(ethylene terephthalate) and Dekalin above 1200C. These crystals were found to have a density of 1.321 g/cm 3 and a hexagonal unit cell of a = b = 15.37A ° , c = 20.78A° and y = 1200 ; Z = 6 molecules/ unit cell; Space Group of The two structures were refined to R-Factors of 9.66% and 14.86% respectively. The molecular conformations of both phases are the same; their ester-groups in ICISt conformation and the glycol residue links in 'gauchC' formation. The trimer molecules in the LT phase are arranged in an ordered manner; whilst in the HTP trimer the glycol residue links are disordered, with two possible conformations for each link.","abstract_html":"Tris (Ethylene Terephthalate) is an oligomer of Polyethylene Terephthalate with a chemical formula of -[O.00.C 6H 4 .CO.O.CH2 .CHJ 3 -. It has two phases, namely the Low Temperature phase (Type A) which isstable below 801C; and the High Temperature Phase (Type B) - stable between 800C and its melting temperature 320 0C. The crystal structures of these two phases have been determined by X-ray diffraction of single crystals. The LTP crystals were crystallised from its solution in DMF at room temperature. The LTP crstals were found to have a monoclinic unit cell and spac%C; the unit cell is a = 16.98A°, b = 19.59A °, c = 8.43A and $ 96.240 with z = 4 molecules/unit cell; d(obs) = 1.367 g/cm 3 . The HTP trimer crystals were formed from a hot solution of tris(ethylene terephthalate) and Dekalin above 1200C. These crystals were found to have a density of 1.321 g/cm 3 and a hexagonal unit cell of a = b = 15.37A ° , c = 20.78A° and y = 1200 ; Z = 6 molecules/ unit cell; Space Group of The two structures were refined to R-Factors of 9.66% and 14.86% respectively. The molecular conformations of both phases are the same; their ester-groups in ICISt conformation and the glycol residue links in 'gauchC' formation. The trimer molecules in the LT phase are arranged in an ordered manner; whilst in the HTP trimer the glycol residue links are disordered, with two possible conformations for each link.","abstract_has_math":false,"creators":["Vyas, Ramesh Harakhji"],"institution":"University of Central Lancashire","degree_name":"phd","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1984,"date_issued":"1984","date_published":"1984","updated_at":"2026-07-24T01:36:16Z","subjects":["F100 - Chemistry","F300 - Physics"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Vyas, Ramesh Harakhji"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1984"]},{"key":"dc:date.issued","label":"Date","values":["1984"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Central Lancashire"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://knowledge.lancashire.ac.uk/id/eprint/20704/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["phd"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["F100 - Chemistry","F300 - Physics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://knowledge.lancashire.ac.uk/id/eprint/20704/1/20704%20Ramesh%20Harakhji%20Vyas%201984%20%20the%20cystal%20structure%20determination%20of%20low%20and%20high%20temperature%20phases%20of%20tris%28ethyleneterephthalate%29%20degree%20of%20Doctor%20of%20Philosophy%20unpublished%201984unknown%20268.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Tris (Ethylene Terephthalate) is an oligomer of Polyethylene Terephthalate with a chemical formula of -[O.00.C 6H 4 .CO.O.CH2 .CHJ 3 -. It has two phases, namely the Low Temperature phase (Type A) which isstable below 801C; and the High Temperature Phase (Type B) - stable between 800C and its melting temperature 320 0C. The crystal structures of these two phases have been determined by X-ray diffraction of single crystals. The LTP crystals were crystallised from its solution in DMF at room temperature. The LTP crstals were found to have a monoclinic unit cell and spac%C; the unit cell is a = 16.98A°, b = 19.59A °, c = 8.43A and $ 96.240 with z = 4 molecules/unit cell; d(obs) = 1.367 g/cm 3 . The HTP trimer crystals were formed from a hot solution of tris(ethylene terephthalate) and Dekalin above 1200C. These crystals were found to have a density of 1.321 g/cm 3 and a hexagonal unit cell of a = b = 15.37A ° , c = 20.78A° and y = 1200 ; Z = 6 molecules/ unit cell; Space Group of The two structures were refined to R-Factors of 9.66% and 14.86% respectively. The molecular conformations of both phases are the same; their ester-groups in ICISt conformation and the glycol residue links in 'gauchC' formation. The trimer molecules in the LT phase are arranged in an ordered manner; whilst in the HTP trimer the glycol residue links are disordered, with two possible conformations for each link."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["The crystal stucture determination of low and high temperature phases of Tris (Ethylene Terephthalate)"]}]}],"canonical_facts":{"dc:creator":["Vyas, Ramesh Harakhji"],"dc:date":["1984"],"dc:date.issued":["1984"],"dc:description.abstract":["Tris (Ethylene Terephthalate) is an oligomer of Polyethylene Terephthalate with a chemical formula of -[O.00.C 6H 4 .CO.O.CH2 .CHJ 3 -. It has two phases, namely the Low Temperature phase (Type A) which isstable below 801C; and the High Temperature Phase (Type B) - stable between 800C and its melting temperature 320 0C. The crystal structures of these two phases have been determined by X-ray diffraction of single crystals. The LTP crystals were crystallised from its solution in DMF at room temperature. The LTP crstals were found to have a monoclinic unit cell and spac%C; the unit cell is a = 16.98A°, b = 19.59A °, c = 8.43A and $ 96.240 with z = 4 molecules/unit cell; d(obs) = 1.367 g/cm 3 . The HTP trimer crystals were formed from a hot solution of tris(ethylene terephthalate) and Dekalin above 1200C. These crystals were found to have a density of 1.321 g/cm 3 and a hexagonal unit cell of a = b = 15.37A ° , c = 20.78A° and y = 1200 ; Z = 6 molecules/ unit cell; Space Group of The two structures were refined to R-Factors of 9.66% and 14.86% respectively. The molecular conformations of both phases are the same; their ester-groups in ICISt conformation and the glycol residue links in 'gauchC' formation. The trimer molecules in the LT phase are arranged in an ordered manner; whilst in the HTP trimer the glycol residue links are disordered, with two possible conformations for each link."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://knowledge.lancashire.ac.uk/id/eprint/20704/1/20704%20Ramesh%20Harakhji%20Vyas%201984%20%20the%20cystal%20structure%20determination%20of%20low%20and%20high%20temperature%20phases%20of%20tris%28ethyleneterephthalate%29%20degree%20of%20Doctor%20of%20Philosophy%20unpublished%201984unknown%20268.pdf"],"dc:language":["en"],"dc:publisher.institution":["University of Central Lancashire"],"dc:relation.isreferencedby":["https://knowledge.lancashire.ac.uk/id/eprint/20704/"],"dc:subject":["F100 - Chemistry","F300 - Physics"],"dc:title":["The crystal stucture determination of low and high temperature phases of Tris (Ethylene Terephthalate)"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["phd"]},"updated_at":"2026-07-24T01:36:16Z"}