{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,17]],"date-time":"2026-10-17T19:00:07Z","timestamp":1792263607773,"version":"4.4.0"},"reference-count":42,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2025,8,9]],"date-time":"2025-08-09T00:00:00Z","timestamp":1754697600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Natural rubber (NR) possesses excellent comprehensive properties and plays an irreplaceable role in both national defense and people\u2019s livelihood. In recent years, lignin, as a new development trend, has emerged as a reinforcing filler in natural rubber, partially replacing traditional carbon black, or serving as an antioxidant in rubber. However, lignin, a polar biomass filler, exhibits poor compatibility with non-polar natural rubber. To address the compatibility issue between the two, this paper adopts an in situ method, utilizing formic acid and hydrogen peroxide to modify natural rubber into two types of epoxidized natural rubber (ENR) with different degrees of epoxidation (E-25% and E-45%). Subsequently, through wet mixing, it is combined with a lignin aqueous solution (20 parts), and ethanol is used as a flocculant to prepare lignin\/ENR composite rubber materials. Comprehensive characterization of the composite rubber materials reveals that after epoxidation modification, the interfacial compatibility between lignin and natural rubber has been significantly improved. Wet mixing also effectively enhances the dispersibility of lignin in the rubber matrix. Compared to natural rubber, the composite material with an epoxidation degree of 25% exhibits significantly superior mechanical properties and thermal stability. The tensile properties of the composite rubber increase from 29.4 MPa to 36.2 MPa, indicating the significant reinforcing effect of lignin. This study aims to investigate the effects of the epoxidation degree (25% and 45%) of epoxidized natural rubber (ENR) and the mixing method on the compatibility and reinforcement performance of composite rubber, providing a new method for preparing high-performance lignin\/ENR composites.<\/jats:p>","DOI":"10.3390\/ma18163736","type":"journal-article","created":{"date-parts":[[2025,8,11]],"date-time":"2025-08-11T09:04:53Z","timestamp":1754903093000},"page":"3736","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Lignin\/Epoxidized Natural Rubber Compounds Based on Wet Mixing: Impact of Epoxidation Degree on the Interface of Compounds"],"prefix":"10.3390","volume":"18","author":[{"given":"Hongbing","family":"Zheng","sequence":"first","affiliation":[{"name":"Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing 100029, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0839-0926","authenticated-orcid":false,"given":"Dongmei","family":"Yue","sequence":"additional","affiliation":[{"name":"Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing 100029, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"110614","DOI":"10.1016\/j.compositesb.2023.110614","article-title":"Influence of a Novel Coupling Agent on the Performance of Recovered Carbon Black Filled Natural Rubber","volume":"255","author":"Zhang","year":"2023","journal-title":"Compos. Part B Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"821","DOI":"10.1146\/annurev-biochem-013118-111107","article-title":"Molecular Mechanisms of Natural Rubber Biosynthesis","volume":"89","author":"Yamashita","year":"2020","journal-title":"Annu. Rev. Biochem."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/S1369-7021(06)71397-9","article-title":"Natural Rubber by a Rubber Man","volume":"9","author":"Martinez","year":"2006","journal-title":"Mater. Today"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1016\/0032-3861(64)90149-1","article-title":"The Chemistry and Physics of Rubber-like Substances","volume":"5","author":"Bawn","year":"1964","journal-title":"Polymer"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2307741","DOI":"10.1002\/advs.202307741","article-title":"Unraveling Non-Uniform Strain-Induced Crystallization Near a Crack Tip in Natural Rubber","volume":"11","author":"Mai","year":"2024","journal-title":"Adv. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.compositesb.2018.08.033","article-title":"Preparation and Properties of Modified Porous Starch\/Carbon Black\/Natural Rubber Composites","volume":"156","author":"Du","year":"2019","journal-title":"Compos. Part B Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"108346","DOI":"10.1016\/j.compositesb.2020.108346","article-title":"Recycling of Waste Tire by Pyrolysis to Recover Carbon Black: Alternative & Environment-Friendly Reinforcing Filler for Natural Rubber Compounds","volume":"200","author":"Dwivedi","year":"2020","journal-title":"Compos. Part B Eng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10965-020-02246-7","article-title":"Chemical Modification of Natural Rubber in Latex Stage for Improved Thermal, Oil, Ozone and Mechanical Properties","volume":"27","author":"Saengdee","year":"2020","journal-title":"J. Polym. Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1800689","DOI":"10.1002\/mame.201800689","article-title":"Lignin-Reinforced Ethylene-Propylene-Diene Copolymer Elastomer via Hydrogen Bonding Interactions","volume":"304","author":"Mei","year":"2019","journal-title":"Macromol. Mater. Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1016\/j.compositesb.2015.02.028","article-title":"Lignocellulosic Fibre Mediated Rubber Composites: An Overview","volume":"76","author":"Zhou","year":"2015","journal-title":"Compos. Part B Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"50866","DOI":"10.1002\/app.50866","article-title":"Recent Advances of Natural Fibers Based Green Rubber Composites: Properties, Current Status, and Future Perspectives","volume":"138","author":"Roy","year":"2021","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2362","DOI":"10.1002\/pc.26546","article-title":"Hybrid Nanocellulose\/Carbon Nanotube\/Natural Rubber Nanocomposites with a Continuous Three-dimensional Conductive Network","volume":"43","author":"Kazemi","year":"2022","journal-title":"Polym. Compos."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2100483","DOI":"10.1002\/mame.202100483","article-title":"Cellulose-Nanofiber-Reinforced Rubber Composites with Resorcinol Resin Prepared by Elastic Kneading","volume":"306","author":"Noguchi","year":"2021","journal-title":"Macromol. Mater. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1246843","DOI":"10.1126\/science.1246843","article-title":"Lignin Valorization: Improving Lignin Processing in the Biorefinery","volume":"344","author":"Ragauskas","year":"2014","journal-title":"Science"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"8031","DOI":"10.1021\/acssuschemeng.2c02113","article-title":"Design of a Lignin-Based Versatile Bioreinforcement for High-Performance Natural Rubber Composites","volume":"10","author":"Li","year":"2022","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1550","DOI":"10.1016\/j.tibtech.2022.09.014","article-title":"Creative Biological Lignin Conversion Routes toward Lignin Valorization","volume":"40","author":"Liu","year":"2022","journal-title":"Trends Biotechnol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"828","DOI":"10.1016\/j.ijbiomac.2019.03.069","article-title":"Valorization of Lignin in Polymer and Composite Systems for Advanced Engineering Applications\u2014A Review","volume":"131","author":"Collins","year":"2019","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_18","first-page":"79","article-title":"Processing and Valorization of Cellulose, Lignin and Lignocellulose Using Ionic Liquids","volume":"5","author":"Xia","year":"2020","journal-title":"J. Bioresour. Bioprod."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"6698","DOI":"10.1039\/D1GC01684A","article-title":"Multifunctional Lignin-Based Nanocomposites and Nanohybrids","volume":"23","author":"Lizundia","year":"2021","journal-title":"Green Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5222","DOI":"10.1039\/C6RA26359C","article-title":"Reinforcing Biofiller \u201cLignin\u201d for High Performance Green Natural Rubber Nanocomposites","volume":"7","author":"Ikeda","year":"2017","journal-title":"RSC Adv."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"5258","DOI":"10.1021\/acssuschemeng.6b00774","article-title":"Influence of Lignin Features on Thermal Stability and Mechanical Properties of Natural Rubber Compounds","volume":"4","author":"Barana","year":"2016","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"410","DOI":"10.1016\/j.ijbiomac.2019.12.182","article-title":"Self-Assembled Lignin-Silica Hybrid Material Derived from Rice Husks as the Sustainable Reinforcing Fillers for Natural Rubber","volume":"145","author":"Xue","year":"2020","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"5337","DOI":"10.1039\/D1GC01115D","article-title":"Bioresourced Fillers for Rubber Composite Sustainability: Current Development and Future Opportunities","volume":"23","author":"Chang","year":"2021","journal-title":"Green Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1016\/j.psep.2020.11.017","article-title":"Lignin Based Nano-Composites: Synthesis and Applications","volume":"145","author":"Parvathy","year":"2021","journal-title":"Process Saf. Environ. Prot."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"113063","DOI":"10.1016\/j.indcrop.2020.113063","article-title":"Toughening of Natural Rubber Nanocomposites by the Incorporation of Nanoscale Lignin Combined with an Industrially Relevant Leaching Process","volume":"159","author":"Hosseinmardi","year":"2021","journal-title":"Ind. Crops Prod."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Qiu, J., Yuan, S., Xiao, H., Liu, J., Shen, T., Tan, Z., Zhuang, W., Ying, H., Li, M., and Zhu, C. (2023). Study on Lignin Amination for Lignin\/SiO2 Nano-Hybrids towards Sustainable Natural Rubber Composites. Int. J. Biol. Macromol., 233.","DOI":"10.1016\/j.ijbiomac.2023.123547"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"109775","DOI":"10.1016\/j.compscitech.2022.109775","article-title":"A Green Dual-Phase Carbon-Silica Nanohybrid Derived from Black Liquor Lignin for Reinforcing Styrene-Butadiene Rubber","volume":"230","author":"Jiang","year":"2022","journal-title":"Compos. Sci. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1661","DOI":"10.1002\/app.1984.070290520","article-title":"Epoxidation of Natural Rubber Latices: Methods of Preparation and Properties of Modified Rubbers","volume":"29","author":"Burfield","year":"1984","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1007\/s42464-019-00029-4","article-title":"Colloidal Properties of Epoxidized Natural Rubber Latex Prepared via Membrane Separation Technology","volume":"22","author":"Singh","year":"2019","journal-title":"J. Rubber Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"573","DOI":"10.1016\/0014-3057(86)90186-2","article-title":"Kinetic Studies of the Performic Acid Epoxidation of Natural Rubber Latex Stabilized by Cationic Surfactant","volume":"22","author":"Gan","year":"1986","journal-title":"Eur. Polym. J."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"796459","DOI":"10.1155\/2015\/796459","article-title":"Influence of Filler from a Renewable Resource and Silane Coupling Agent on the Properties of Epoxidized Natural Rubber Vulcanizates","volume":"2015","author":"Pongdong","year":"2015","journal-title":"J. Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"42044","DOI":"10.1002\/app.42044","article-title":"In Situ Dispersion and Compatibilization of Lignin\/Epoxidized Natural Rubber Composites: Reactivity, Morphology and Property","volume":"132","author":"Jiang","year":"2015","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1007\/s13726-017-0534-0","article-title":"A Comparative Study on Selective Properties of Kraft Lignin\u2013Natural Rubber Composites Containing Different Plasticizers","volume":"26","author":"Datta","year":"2017","journal-title":"Iran. Polym. J."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Wang, H., Liu, W., Huang, J., Yang, D., and Qiu, X. (2018). Bioinspired Engineering towards Tailoring Advanced Lignin\/Rubber Elastomers. Polymers, 10.","DOI":"10.3390\/polym10091033"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Mohamad Aini, N., Othman, N., Hussin, M., Sahakaro, K., and Hayeemasae, N. (2019). Hydroxymethylation-Modified Lignin and Its Effectiveness as a Filler in Rubber Composites. Processes, 7.","DOI":"10.3390\/pr7050315"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/j.indcrop.2004.04.022","article-title":"Characterisation of Structure-Dependent Functional Properties of Lignin with Infrared Spectroscopy","volume":"20","author":"Boeriu","year":"2004","journal-title":"Ind. Crops Prod."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Mohamad Aini, N.A., Othman, N., Hussin, M.H., Sahakaro, K., and Hayeemasae, N. (2020). Lignin as Alternative Reinforcing Filler in the Rubber Industry: A Review. Front. Mater., 6.","DOI":"10.3389\/fmats.2019.00329"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1072","DOI":"10.1021\/sc500087z","article-title":"Progress in Green Polymer Composites from Lignin for Multifunctional Applications: A Review","volume":"2","author":"Thakur","year":"2014","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"11843","DOI":"10.1021\/acssuschemeng.8b02145","article-title":"Lignin Based Functional Additives for Natural Rubber","volume":"6","author":"Barana","year":"2018","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1016\/j.polymertesting.2017.05.043","article-title":"A Rheological Method Exploiting Cole-Cole Plot Allows Gel Quantification in Natural Rubber","volume":"61","author":"Rolere","year":"2017","journal-title":"Polym. Test."},{"key":"ref_41","first-page":"775","article-title":"Properties of Epoxidized Natural Rubber Tread Compound: The Hybrid Reinforcing Effect of Silica and Silane System","volume":"24","author":"Sarkawi","year":"2016","journal-title":"Polym. Polym. Compos."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1226","DOI":"10.1002\/app.24530","article-title":"Role of Lignin Filler in Stabilization of Natural Rubber\u2013Based Composites","volume":"103","author":"Osvald","year":"2007","journal-title":"J. Appl. Polym. Sci."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/16\/3736\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:27:20Z","timestamp":1760034440000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/16\/3736"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,9]]},"references-count":42,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2025,8]]}},"alternative-id":["ma18163736"],"URL":"https:\/\/doi.org\/10.3390\/ma18163736","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8,9]]}}}