[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-443968-105":59,"doc-detail-443968-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","cyclic-polyglycolide-by-means-of-metal-acetylacetonates","Cyclic polyglycolide by means of metal acetylacetonates","","Glycolide was polymerized in bulk at 160 °C using various metal acetylacetonates as catalysts, with zirconium acetylacetonate enabling rapid polymerization even at 130 °C. Cyclic poly(glycolic acid) formation was confirmed by MALDI-TOF mass spectrometry, consistent with a ring-expansion polymerization mechanism. Even-numbered cycles were favored depending on conditions, delivering number-average molecular weights of 2000–3500 g mol−1 and dispersities below 2.0. WAXS showed crystal lattices matching known linear PGAs, supporting comparisons of crystallinity from DSC values.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/cyclic-polyglycolide-by-means-of-metal-acetylacetonates/443968/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/cyclic-polyglycolide-by-means-of-metal-acetylacetonates/443968.png","ImageObject",300,407,{"name":92,"@type":93},"Sarah ","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-03","2026-09-29",true,{"@type":102,"interactionType":103,"userInteractionCount":81},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"Which catalyst proved most efficient for cyclic polyglycolide formation?","Question",{"text":112,"@type":113},"Zirconium acetylacetonate was particularly efficient, enabling rapid polymerization even at 130 °C.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How was the formation of cyclic poly(glycolic acid) verified?",{"text":117,"@type":113},"Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry confirmed cyclic poly(glycolic acid) formation.",{"name":119,"@type":110,"acceptedAnswer":120},"What structural comparison was made between cyclic and linear PGAs?",{"text":121,"@type":113},"Wide-angle X-ray scattering (WAXS) powder patterns showed that the crystal lattice in cyclic PGA matches that of known linear PGAs, allowing crystallinity comparisons using DSC-derived values.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},443968,1790791473,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":81,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":39,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":143,"read_time":46},962085320529,"https://ap-avatar.wpscdn.com/davatar_9964176cb1d06d4a9deccf72a44ae3dc","RSC Advances  \nPAPER  \nCite this: RSC Adv., 2026, 16, 1757  \nReceived 17th October 2025 Accepted 14th December 2025 DOI: 10.1039/d5ra07961f  \n[rsc.li/rsc-advances](rsc.li/rsc-advances)  \nCyclic polyglycolide by means of metal acetylacetonates  \nSteffen M. Weidner,  a Andreas Meyer, b Jana Falkenhagen  cand Hans R. Kricheldorf*c  \nGlycolide was polymerized in bulk at 160 °C using various metal acetylacetonates as catalysts. Zirconium acetylacetonate was particularly efficient, enabling rapid polymerization even at 130 °C. The formation of cyclic poly(glycolic acid) (PGA), most likely via a ring-expansion polymerization (REP) mechanism, was proven by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Depending on the polymerization conditions, the formation of even-numbered cycles was favored to varying degrees. Number-average molecular weights (Mn) in the range of 2000–3500 g mol−1 were achieved with dispersities below 2 .0. Wide-angle X-ray scattering (WAXS) powder patterns showed that the crystal lattice was the same as that of known linear PGAs, regardless of the Mn values. These patterns enabled a comparison of crystallinities with values derived from DSC measurements.  \nIntroduction  \nInterest in the synthesis and characterization of polyglycolide (PGA) increased among academics and industry members when, in 1952/53, members of American Cyanamide and DuPont 􀀁led patents describing the synthesis and properties of this biodegradable polyester, mentioning its potential usefulness in medical applications.1–3 These initial patents were followed by a relatively slow but steady stream of additional patents and academic research articles.4–27 In 1968, American Cyanamide commercialized PGA 􀀁bres under the trademark“Dexon' for use as a resorbable medical suture. A few years later, Ethicon Inc., a subsidiary of Johnson & Johnson, followed with the commercialization of a medical suture under the trademark“Vicryl”. This suture is made from a copolyester of glycolic and lactic acid, containing more than 90% glycolic acid. These two sutures are still widely used in the 21st century. Over the past thirty years, further applications have emerged, such as 􀀁lms  \nfor packaging purposes under the trademark “Kuradex.”  \nPGA has a unique combination of properties. The absence of substituents enables PGA to form a compact crystal lattice through the parallel arrangement of linear chains in a planar zigzag conformation. This results in a structure resembling the b-sheet structure of polyglycine. This dense chain packing results in a high-density crystalline PGA with a speci􀀁c density that can reach values around 1.69 g cm−3 and a hardness that is  \naBundesanstalt für Materialforschung und -prüfung–BAM, Richard Willsttter Strasse11, D-12489 Berlin, Germany  \nbUniversitt Hamburg, Institut für Physikalische Chemie, Grindelallee 117, Hamburg D-20146, Germany  \nc Universitt Hamburg, Institut für Technische und Makromolekulare Chemie, Bundesstrasse 45, D-20146 Hamburg, Germany. E-mail: [hrkricheldorf@aol.de](hrkricheldorf@aol.de)  \nrelatively high compared to other aliphatic polyesters.6 Another corollary is a stable crystal lattice with a high melting temperature (Tm up to 232 °C) and a high melting enthalpy (theoretical DH = 206 J g−1) .14,20 The tight chain packing also provides excellent barrier properties against gases, particularly non-polar ones. These properties, combined with high mechanical strength, make PGA an interesting material for food packaging. However, applications and research papers dealing with PGA are scarce compared to those dealing with polylactide because PGA has a few negative properties. First, glycolide polymerization, the standard technical procedure, is highly exothermic, and controlling the heat 􀀃ow is difficult when polymerizing several tons of material. Second, processing from the melt requires temperatures above 230 °C, which pose a high risk of thermal degradation and discoloration. T","cbCaikYlmYzNo8x1","https://ap.wps.com/l/cbCaikYlmYzNo8x1","pdf",1013208,"English","# Introduction\n## Polymerization approach and catalysts\n## Evidence for cyclic PGA formation\n## Molecular weight, dispersity, and cycle selectivity\n## Solid-state structure: WAXS and DSC crystallinity comparison","[{\"question\":\"Which catalyst proved most efficient for cyclic polyglycolide formation?\",\"answer\":\"Zirconium acetylacetonate was particularly efficient, enabling rapid polymerization even at 130 °C.\"},{\"question\":\"How was the formation of cyclic poly(glycolic acid) verified?\",\"answer\":\"Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry confirmed cyclic poly(glycolic acid) formation.\"},{\"question\":\"What structural comparison was made between cyclic and linear PGAs?\",\"answer\":\"Wide-angle X-ray scattering (WAXS) powder patterns showed that the crystal lattice in cyclic PGA matches that of known linear PGAs, allowing crystallinity comparisons using DSC-derived values.\"}]","Cyclic polyglycolide by means of metal acetylacetonates | PDF",1790706247]