[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-439303-105":59,"doc-detail-439303-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","recycling-of-polyurethane-waste-facile-hydrothermal-conversion-using-acidic-and-basic-additives","Recycling of Polyurethane Waste: Facile Hydrothermal Conversion Using Acidic and Basic Additives","","Polyurethane (PU) is a widely utilized plastic, and chemical recycling is a key route toward circular use. This study evaluates hydrothermal conversion of PU with and without acidic and basic catalysts, comparing non-catalytic depolymerisation with catalytic performance. Catalysis improves PU conversion and increases 2,4-toluenediamine (TDA) yield, with ethylenediamine outperforming NaOH, H2SO4, and acetic acid. The results highlight organic amine/organic base advantages via ionic interactions and more uniform catalyst distribution at vapour–liquid equilibrium.",{"@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/recycling-of-polyurethane-waste-facile-hydrothermal-conversion-using-acidic-and-basic-additives/439303/",{"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/recycling-of-polyurethane-waste-facile-hydrothermal-conversion-using-acidic-and-basic-additives/439303.png","ImageObject",300,407,{"name":92,"@type":93},"Alex Sinclair","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-01","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},"What is the main goal of the hydrothermal conversion study on polyurethane waste?","Question",{"text":112,"@type":113},"To evaluate how hydrothermal treatment depolymerises polyurethane waste, and how acidic and basic additives affect conversion and product yield.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How do catalytic and non-catalytic hydrothermal approaches compare?",{"text":117,"@type":113},"Both routes enable depolymerisation to monomers, but the use of catalysts improves PU conversion and increases the yield of 2,4-toluenediamine (TDA).",{"name":119,"@type":110,"acceptedAnswer":120},"Which additive shows the best catalytic performance and at what conditions?",{"text":121,"@type":113},"Ethylenediamine, an organic amine, shows the highest activity, achieving a TDA yield of 13.6 wt% and PU conversion of 28.2% at 180°C.","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},439303,1790711600,{"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":44,"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":144},1099523882182,"https://ap-avatar.wpscdn.com/davatar_6f874abed73319feea01a86fa6f0fab8","ChemSusChem  \nRESEARCH ARTICLE   \nRecycling of Polyurethane Waste: Facile Hydrothermal Conversion Using Acidic and Basic Additives  \nHongqi Wang  | Himanshu Gupta | N. Raveendran Shiju   \nCatalysis Engineering Group, Van ‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, Netherlands Correspondence: N. Raveendran Shiju ([n.r.shiju@uva.nl](n.r.shiju@uva.nl))  \nReceived: 18 October 2025 | Revised: 24 November 2025 | Accepted: 24 November 2025  \nKeywords: base | catalyst | hydrolysis | hydrothermal liquefaction | polyurethane waste  \nABSTRACT  \nPolyurethane (PU) is a widely utilised plastic material due to its versatile properties. The chemical recycling, especially by hydrothermal treatment, is an effective way to achieve the circular use of PU. This article reports the results of hydrothermal treatment of PU with and without the use of acidic and basic catalysts. Both non-catalytic and catalytic approaches showed that PU could bedepolymerised to the monomers using hydrothermal treatment. The use of a catalyst improved PU conversion and 2,4-toluenediamine (TDA) yield. An organic amine showed better catalytic activity than inorganic base NaOH, inorganic acid H2SO4, and organic acid acetic acid. Among the catalysts tested, the organic amine ethylenediamine exhibited the highest activity, achieving a TDA yield of 13.6 wt% and a PU conversion of 28.2% at 180°C. Organic bases outperformed inorganic acids and bases, such as H2SO4, acetic acid, and NaOH, which is attributed to their ability to form ionic interactions with PU-derived zwitterions and their uniform distribution across vapour and liquid phases under vapour–liquid equilibrium.  \n1 | Introduction  \nIn recent years, plastics waste management has become a major global concern, driving increasing research into chemical recycling and circular economy strategies to mitigate environmental impacts. Advanced conversion processes such as hydrothermal liquefaction (HTL) and pyrolysis have shown promise for transforming mixed or polyolefin-rich plastics waste into valuable hydrocarbons and reusable chemical feedstocks, thereby reducing dependence on virgin fossil resources and enabling material circularity [1–4] . Beyond polyolefins, chemical recycling approaches are also being extended to condensation polymers, such as polyethylene terephthalate (PET), where catalytic depolymerisation methods like glycolysis have demonstrated efficient recovery of monomers for reuse in new materials [5–7] . Similarly, emerging strategies are addressing the recycling and reuse of specialised polymer systems such as olefinic battery separators and thermoset plastics, expanding the scope of circular technologies to more complex waste streams [8] .  \nPolyurethane (PU) is a common and versatile polymer widely used in our society due to its durability and low cost, such as flexible foam in furniture and rigid foam in automotive interiors [9, 10] . PU can be tailored into thermoplastic or thermoset forms, depending on the polyols and polyisocyanates employed in the production process [11] . The urethane group (–HN–COO–) is the typical functional group in PU, irrespective of the utilised polyols and polyisocyanates. The recycling of PU waste is not only crucial for alleviating the environmental burden associated with the current disposal method of landfilling and but also for recovering valuable feedstocks in a sustainable and circular manner.  \nPU waste could be recycled by both mechanical and chemical methods [12] . The physical treatment in mechanical recycling requires a high level of purity and may cause the degradation of product quality [13] . The chemical recycling includes glycolysis, hydrolysis and pyrolysis [9] . Glycolysis refers to the depolymerisation of PU through transesterification reactions with a glycol, typically conducted under elevated temperature and  \nThis is an open access article under the terms of the Creative Commons Attribution License, which permits use,","cbCairAvFSAZ4EB8","https://ap.wps.com/l/cbCairAvFSAZ4EB8","pdf",981935,"English","# Introduction\n## Background on chemical recycling and circular economy\n## Role of hydrolysis and hydrothermal liquefaction for PU recycling","[{\"question\":\"What is the main goal of the hydrothermal conversion study on polyurethane waste?\",\"answer\":\"To evaluate how hydrothermal treatment depolymerises polyurethane waste, and how acidic and basic additives affect conversion and product yield.\"},{\"question\":\"How do catalytic and non-catalytic hydrothermal approaches compare?\",\"answer\":\"Both routes enable depolymerisation to monomers, but the use of catalysts improves PU conversion and increases the yield of 2,4-toluenediamine (TDA).\"},{\"question\":\"Which additive shows the best catalytic performance and at what conditions?\",\"answer\":\"Ethylenediamine, an organic amine, shows the highest activity, achieving a TDA yield of 13.6 wt% and PU conversion of 28.2% at 180°C.\"}]","Recycling of Polyurethane Waste: Facile Hydrothermal Conversion Using Acidic and Basic Additives | PDF",1790688098,23]