{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:50791"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:50791","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Structure-property relationship of aliphatic segmented poly(ester amide)s","abstract":"This thesis focuses on the synthesis, characterization and applications of aliphatic segmented poly(ester amide)s (PEA)s for use as potential biomaterials. Three different series of PEAs with different microstructures containing isolated, two and three adjacent amide groups within a polybutylene adipate (PBA) chain have been synthesized. Analytical techniques such as NMR (liquid and solid-state), SEC, DSC, FT-IR, WAXD and microscopy (AFM, SEM, optical) have been extensively used to characterize the synthesized monomers and PEAs. Thermal properties have been determined and correlated to features like morphology and crystallization behaviour; structure-property relationship of these polymers were established. The preparation of tailor made monomers for the synthesis of PEAs was carried out by ring opening of epsilon-caprolactam, epsilon-caprolactone or delta-valerolactone with 1,4-diaminobutane, 4-aminobutanol, 3-aminopropanol and/or 2-aminoethanol. These preformed monomers which are alpha,omega-diamines, alpha,omega-amino alcohols or alpha,omega-diols, each containing an in-built amide bond, were obtained in high purity and yields. Synthesis of the PEAs containing an isolated amide group, two or three adjacent amide groups was achieved by a two-step melt polycondensation of the preformed monomers with 1,4-butanediol and dimethyl adipate. In the first step, trans-esterification was carried out so as to avoid a random microstructure and hence, PEAs with segmented microstructure could be obtained. In the second step, polycondensation took place. Further, the amide content in each series could be varied by taking different ratios of the preformed monomer to 1,4-butanediol. High molecular weight PEAs were obtained in good yield and NMR analyses showed that no side reactions had taken place. Thermal analyses revealed that the length of the amide segment, functional groups participating in the crystallization process as well as the amide concentration influenced the transition temperatures and their enthalpies. For the three-adjacent amide series, mainly the amide groups crystallize and only a single endotherm and exotherm was seen. The melting and crystallization temperature increase with increasing amide content. Similar trend was also observed for the two-adjacent amide series of PEAs but here, both ester and amide groups co-crystallize and show multiple endotherms and exotherms. In the isolated amide series, mainly ester groups formed the hard domains and only at very high amide content, ester-amide co-crystallization was observed. FT-IR analyses revealed that the PEAs crystallize mainly in the alpha-form found in even-even nylons and the chains are bridged via hydrogen bonds. Morphology of the two-adjacent amide series of PEAs was investigated in detail using solid state NMR analyses. Spin diffusion experiments were performed to determine the domain sizes of the rigid, interface and mobile phases. A correlation of these domain sizes with the amide content in the PEA was successfully established. 13C solid state NMR analyses gave information about the functional groups participating in the crystalline and amorphous phases which were in line with the observed thermal properties. The hydrolytic degradation of the synthesized PEAs was evaluated in PBS buffer at 37°C over a time period of 24 weeks. The PEAs showed slow degradation kinetics and a maximum mass loss of 7% over the entire time period which proceeded by cleavage of the ester bonds. Further, PEA foils sustain cell growth and are non-cytotoxic to mouse fibroblasts (L929) cells. Electrospinning of the two-adjacent amide series of PEAs was carried out from solution in order to obtain non wovens for tissue engineering purposes. Among a series of solvents and solvent mixtures used, CHCl3/HCOOH mixtures gave the best results. Small amounts of formic acid were added to break the hydrogen bonds in the polymers. Effect of polymer concentration, microstructure and applied voltage on the resulting fibre diameter and morphology were also studied. Fibre quality and homogeneity enhanced with increasing amide content and polymer concentration and these factors played a decisive role in obtaining uniform, randomly oriented, homogeneous fibres in the nanometre range.","abstract_html":"This thesis focuses on the synthesis, characterization and applications of aliphatic segmented poly(ester amide)s (PEA)s for use as potential biomaterials. Three different series of PEAs with different microstructures containing isolated, two and three adjacent amide groups within a polybutylene adipate (PBA) chain have been synthesized. Analytical techniques such as NMR (liquid and solid-state), SEC, DSC, FT-IR, WAXD and microscopy (AFM, SEM, optical) have been extensively used to characterize the synthesized monomers and PEAs. Thermal properties have been determined and correlated to features like morphology and crystallization behaviour; structure-property relationship of these polymers were established. The preparation of tailor made monomers for the synthesis of PEAs was carried out by ring opening of epsilon-caprolactam, epsilon-caprolactone or delta-valerolactone with 1,4-diaminobutane, 4-aminobutanol, 3-aminopropanol and/or 2-aminoethanol. These preformed monomers which are alpha,omega-diamines, alpha,omega-amino alcohols or alpha,omega-diols, each containing an in-built amide bond, were obtained in high purity and yields. Synthesis of the PEAs containing an isolated amide group, two or three adjacent amide groups was achieved by a two-step melt polycondensation of the preformed monomers with 1,4-butanediol and dimethyl adipate. In the first step, trans-esterification was carried out so as to avoid a random microstructure and hence, PEAs with segmented microstructure could be obtained. In the second step, polycondensation took place. Further, the amide content in each series could be varied by taking different ratios of the preformed monomer to 1,4-butanediol. High molecular weight PEAs were obtained in good yield and NMR analyses showed that no side reactions had taken place. Thermal analyses revealed that the length of the amide segment, functional groups participating in the crystallization process as well as the amide concentration influenced the transition temperatures and their enthalpies. For the three-adjacent amide series, mainly the amide groups crystallize and only a single endotherm and exotherm was seen. The melting and crystallization temperature increase with increasing amide content. Similar trend was also observed for the two-adjacent amide series of PEAs but here, both ester and amide groups co-crystallize and show multiple endotherms and exotherms. In the isolated amide series, mainly ester groups formed the hard domains and only at very high amide content, ester-amide co-crystallization was observed. FT-IR analyses revealed that the PEAs crystallize mainly in the alpha-form found in even-even nylons and the chains are bridged via hydrogen bonds. Morphology of the two-adjacent amide series of PEAs was investigated in detail using solid state NMR analyses. Spin diffusion experiments were performed to determine the domain sizes of the rigid, interface and mobile phases. A correlation of these domain sizes with the amide content in the PEA was successfully established. 13C solid state NMR analyses gave information about the functional groups participating in the crystalline and amorphous phases which were in line with the observed thermal properties. The hydrolytic degradation of the synthesized PEAs was evaluated in PBS buffer at 37°C over a time period of 24 weeks. The PEAs showed slow degradation kinetics and a maximum mass loss of 7% over the entire time period which proceeded by cleavage of the ester bonds. Further, PEA foils sustain cell growth and are non-cytotoxic to mouse fibroblasts (L929) cells. Electrospinning of the two-adjacent amide series of PEAs was carried out from solution in order to obtain non wovens for tissue engineering purposes. Among a series of solvents and solvent mixtures used, CHCl3/HCOOH mixtures gave the best results. Small amounts of formic acid were added to break the hydrogen bonds in the polymers. Effect of polymer concentration, microstructure and applied voltage on the resulting fibre diameter and morphology were also studied. Fibre quality and homogeneity enhanced with increasing amide content and polymer concentration and these factors played a decisive role in obtaining uniform, randomly oriented, homogeneous fibres in the nanometre range.","abstract_has_math":false,"creators":["Garg, Priya"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Möller, Martin"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010","date_published":"2010","updated_at":"2026-07-30T19:40:25Z","subjects":["info:eu-repo/classification/ddc/540","Polymere","Biomaterial","Chemie","polymer","biomaterials","electrospinning","morphology"],"languages":["eng"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113318%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113318%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113318%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/50791","outbound_label":"Repository record","outbound_source":"dc:identifier"},"source_record":{"url":"https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A50791","prefix":"oai_dc"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Möller, Martin"]},{"key":"dc:creator","label":"Author","values":["Garg, Priya"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2010"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-31966"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/540","Polymere","Biomaterial","Chemie","polymer","biomaterials","electrospinning","morphology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/50791","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113318%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This thesis focuses on the synthesis, characterization and applications of aliphatic segmented poly(ester amide)s (PEA)s for use as potential biomaterials. Three different series of PEAs with different microstructures containing isolated, two and three adjacent amide groups within a polybutylene adipate (PBA) chain have been synthesized. Analytical techniques such as NMR (liquid and solid-state), SEC, DSC, FT-IR, WAXD and microscopy (AFM, SEM, optical) have been extensively used to characterize the synthesized monomers and PEAs. Thermal properties have been determined and correlated to features like morphology and crystallization behaviour; structure-property relationship of these polymers were established. The preparation of tailor made monomers for the synthesis of PEAs was carried out by ring opening of epsilon-caprolactam, epsilon-caprolactone or delta-valerolactone with 1,4-diaminobutane, 4-aminobutanol, 3-aminopropanol and/or 2-aminoethanol. These preformed monomers which are alpha,omega-diamines, alpha,omega-amino alcohols or alpha,omega-diols, each containing an in-built amide bond, were obtained in high purity and yields. Synthesis of the PEAs containing an isolated amide group, two or three adjacent amide groups was achieved by a two-step melt polycondensation of the preformed monomers with 1,4-butanediol and dimethyl adipate. In the first step, trans-esterification was carried out so as to avoid a random microstructure and hence, PEAs with segmented microstructure could be obtained. In the second step, polycondensation took place. Further, the amide content in each series could be varied by taking different ratios of the preformed monomer to 1,4-butanediol. High molecular weight PEAs were obtained in good yield and NMR analyses showed that no side reactions had taken place. Thermal analyses revealed that the length of the amide segment, functional groups participating in the crystallization process as well as the amide concentration influenced the transition temperatures and their enthalpies. For the three-adjacent amide series, mainly the amide groups crystallize and only a single endotherm and exotherm was seen. The melting and crystallization temperature increase with increasing amide content. Similar trend was also observed for the two-adjacent amide series of PEAs but here, both ester and amide groups co-crystallize and show multiple endotherms and exotherms. In the isolated amide series, mainly ester groups formed the hard domains and only at very high amide content, ester-amide co-crystallization was observed. FT-IR analyses revealed that the PEAs crystallize mainly in the alpha-form found in even-even nylons and the chains are bridged via hydrogen bonds. Morphology of the two-adjacent amide series of PEAs was investigated in detail using solid state NMR analyses. Spin diffusion experiments were performed to determine the domain sizes of the rigid, interface and mobile phases. A correlation of these domain sizes with the amide content in the PEA was successfully established. 13C solid state NMR analyses gave information about the functional groups participating in the crystalline and amorphous phases which were in line with the observed thermal properties. The hydrolytic degradation of the synthesized PEAs was evaluated in PBS buffer at 37°C over a time period of 24 weeks. The PEAs showed slow degradation kinetics and a maximum mass loss of 7% over the entire time period which proceeded by cleavage of the ester bonds. Further, PEA foils sustain cell growth and are non-cytotoxic to mouse fibroblasts (L929) cells. Electrospinning of the two-adjacent amide series of PEAs was carried out from solution in order to obtain non wovens for tissue engineering purposes. Among a series of solvents and solvent mixtures used, CHCl3/HCOOH mixtures gave the best results. Small amounts of formic acid were added to break the hydrogen bonds in the polymers. Effect of polymer concentration, microstructure and applied voltage on the resulting fibre diameter and morphology were also studied. Fibre quality and homogeneity enhanced with increasing amide content and polymer concentration and these factors played a decisive role in obtaining uniform, randomly oriented, homogeneous fibres in the nanometre range."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University VII, 213 S. : Ill., graph. Darst. (2010). = Aachen, Techn. Hochsch., Diss., 2010"]},{"key":"dc:title","label":"Title","values":["Structure-property relationship of aliphatic segmented poly(ester amide)s"]}]}],"canonical_facts":{"dc:contributor":["Möller, Martin"],"dc:coverage":["DE"],"dc:creator":["Garg, Priya"],"dc:date":["2010"],"dc:description":["This thesis focuses on the synthesis, characterization and applications of aliphatic segmented poly(ester amide)s (PEA)s for use as potential biomaterials. Three different series of PEAs with different microstructures containing isolated, two and three adjacent amide groups within a polybutylene adipate (PBA) chain have been synthesized. Analytical techniques such as NMR (liquid and solid-state), SEC, DSC, FT-IR, WAXD and microscopy (AFM, SEM, optical) have been extensively used to characterize the synthesized monomers and PEAs. Thermal properties have been determined and correlated to features like morphology and crystallization behaviour; structure-property relationship of these polymers were established. The preparation of tailor made monomers for the synthesis of PEAs was carried out by ring opening of epsilon-caprolactam, epsilon-caprolactone or delta-valerolactone with 1,4-diaminobutane, 4-aminobutanol, 3-aminopropanol and/or 2-aminoethanol. These preformed monomers which are alpha,omega-diamines, alpha,omega-amino alcohols or alpha,omega-diols, each containing an in-built amide bond, were obtained in high purity and yields. Synthesis of the PEAs containing an isolated amide group, two or three adjacent amide groups was achieved by a two-step melt polycondensation of the preformed monomers with 1,4-butanediol and dimethyl adipate. In the first step, trans-esterification was carried out so as to avoid a random microstructure and hence, PEAs with segmented microstructure could be obtained. In the second step, polycondensation took place. Further, the amide content in each series could be varied by taking different ratios of the preformed monomer to 1,4-butanediol. High molecular weight PEAs were obtained in good yield and NMR analyses showed that no side reactions had taken place. Thermal analyses revealed that the length of the amide segment, functional groups participating in the crystallization process as well as the amide concentration influenced the transition temperatures and their enthalpies. For the three-adjacent amide series, mainly the amide groups crystallize and only a single endotherm and exotherm was seen. The melting and crystallization temperature increase with increasing amide content. Similar trend was also observed for the two-adjacent amide series of PEAs but here, both ester and amide groups co-crystallize and show multiple endotherms and exotherms. In the isolated amide series, mainly ester groups formed the hard domains and only at very high amide content, ester-amide co-crystallization was observed. FT-IR analyses revealed that the PEAs crystallize mainly in the alpha-form found in even-even nylons and the chains are bridged via hydrogen bonds. Morphology of the two-adjacent amide series of PEAs was investigated in detail using solid state NMR analyses. Spin diffusion experiments were performed to determine the domain sizes of the rigid, interface and mobile phases. A correlation of these domain sizes with the amide content in the PEA was successfully established. 13C solid state NMR analyses gave information about the functional groups participating in the crystalline and amorphous phases which were in line with the observed thermal properties. The hydrolytic degradation of the synthesized PEAs was evaluated in PBS buffer at 37°C over a time period of 24 weeks. The PEAs showed slow degradation kinetics and a maximum mass loss of 7% over the entire time period which proceeded by cleavage of the ester bonds. Further, PEA foils sustain cell growth and are non-cytotoxic to mouse fibroblasts (L929) cells. Electrospinning of the two-adjacent amide series of PEAs was carried out from solution in order to obtain non wovens for tissue engineering purposes. Among a series of solvents and solvent mixtures used, CHCl3/HCOOH mixtures gave the best results. Small amounts of formic acid were added to break the hydrogen bonds in the polymers. Effect of polymer concentration, microstructure and applied voltage on the resulting fibre diameter and morphology were also studied. Fibre quality and homogeneity enhanced with increasing amide content and polymer concentration and these factors played a decisive role in obtaining uniform, randomly oriented, homogeneous fibres in the nanometre range."],"dc:identifier":["https://publications.rwth-aachen.de/record/50791","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-113318%22"],"dc:language":["eng"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-31966"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University VII, 213 S. : Ill., graph. Darst. (2010). = Aachen, Techn. Hochsch., Diss., 2010"],"dc:subject":["info:eu-repo/classification/ddc/540","Polymere","Biomaterial","Chemie","polymer","biomaterials","electrospinning","morphology"],"dc:title":["Structure-property relationship of aliphatic segmented poly(ester amide)s"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:40:25Z"}