{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T17:10:15Z","timestamp":1785431415211,"version":"3.56.0"},"reference-count":39,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,5]],"date-time":"2026-07-05T00:00:00Z","timestamp":1783209600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007120","name":"King Mongkut\u2019s Institute of Technology Ladkrabang","doi-asserted-by":"publisher","award":["KREF186727"],"award-info":[{"award-number":["KREF186727"]}],"id":[{"id":"10.13039\/501100007120","id-type":"DOI","asserted-by":"publisher"}]},{"award":["KREF186727"],"award-info":[{"award-number":["KREF186727"]}],"id":[{"id":"https:\/\/ror.org\/055mf0v62","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gels"],"abstract":"<jats:p>Polymer\/Silica aerogel (SA) composites improve mechanical properties strategically, but the mixing process disrupts the aerogel\u2019s structure, reducing its efficiency due to polymer chains filling the pores. Pre-vulcanized natural rubber latex (PVNRL) with a higher crosslink density can strain the moving chains, thereby preserving the SA-porous structure in the bulk composite for thermal insulation materials. This study aimed to investigate the effects of PVNRL pre-vulcanization time and SA-immersion time in PVNRL. For PVNRL\/SA composite preparation, various PVNRL, from 0 days to 8 days of pre-vulcanization time, were mixed with a fixed SA content of 20 parts per hundred of rubber (phr) using a latex compounding method. Subsequently, the PVNRL\/SA slurries were cast on glass plates with 0, 3, and 6 days to obtain the PVNRL\/SA composite. Considering the effect of pre-vulcanization time, the crosslink density of the composite increased and revealed a peak at PVNRL\/SA with 8-day PVNRL by 7.277 \u00b1 0.881 \u03bcmol g\u22121, corresponding to the closest percentage of pore area in the SA\u2019s structure to the pristine SA, and eventually a 42.41% lower thermal conductivity than the PVNRL\/SA with 0-day PVNRL exhibited. In addition, the thermal conductivity increased more slowly over immersion time with the presence of 8-day PVNRL. The proposed correlation states that increasing the pre-vulcanization improves the thermal insulation performance of PVNRL\/SA composites, emphasizing the reduction of filled SA\u2019s pore with unvulcanized NR chains. Furthermore, the PVNRL\/SA composite with 8-day PVNRL maintains thermal stability at 387.3 \u00b0C, and can be flexed at room temperature. These fascinating discoveries may be advantageous for further applications related to thin-film and flexible thermal insulation materials.<\/jats:p>","DOI":"10.3390\/gels12070599","type":"journal-article","created":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T13:43:14Z","timestamp":1783345394000},"page":"599","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effect of Pre-Vulcanization Time on Structure and Thermal Insulation of Natural Rubber Latex\/Silica Aerogel Composites"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1022-6911","authenticated-orcid":false,"given":"Chayanan","family":"Boonrawd","sequence":"first","affiliation":[{"name":"Department of Nanoscience and Nanotechnology, School of Integrated Innovative Technology, King Mongkut\u2019s Institute of Technology Ladkrabang, Bangkok 10520, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4633-655X","authenticated-orcid":false,"given":"Wanwilai","family":"Vittayakorn","sequence":"additional","affiliation":[{"name":"Department of Nanoscience and Nanotechnology, School of Integrated Innovative Technology, King Mongkut\u2019s Institute of Technology Ladkrabang, Bangkok 10520, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5689-6406","authenticated-orcid":false,"given":"Darapond","family":"Triampo","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Faculty of Science, Mahidol University, Nakhon Pathom 73170, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6368-1171","authenticated-orcid":false,"given":"Supan","family":"Yodyingyong","sequence":"additional","affiliation":[{"name":"Institute for Innovative Learning, Mahidol University, Nakhon Pathom 73170, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1016\/j.energy.2015.07.109","article-title":"Thermal transport in nano-porous insulation of aerogel: Factors, models and outlook","volume":"90","author":"Tang","year":"2015","journal-title":"Energy"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Ramesh, R., and Barisik, M. (2026). Thermal Conductivity in Nanoporous Aerogels: A Critical Review of Gas and Solid Conduction Models and Structure-Property Relations. Gels, 12.","DOI":"10.3390\/gels12040334"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1002\/(SICI)1521-3773(19980202)37:1\/2<22::AID-ANIE22>3.0.CO;2-I","article-title":"Aerogels\u2014Airy Materials: Chemistry, Structure, and Properties","volume":"37","author":"Schubert","year":"1998","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"971","DOI":"10.1126\/science.255.5047.971","article-title":"Thermal Conductivity of Monolithic Organic Aerogels","volume":"255","author":"Lu","year":"1992","journal-title":"Science"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.jmatprotec.2007.10.060","article-title":"Silica aerogel; synthesis, properties and characterization","volume":"199","author":"Dorcheh","year":"2008","journal-title":"J. Mater. Process. Technol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1016\/j.enbuild.2010.12.012","article-title":"Aerogel insulation for building applications: A state-of-the-art review","volume":"43","author":"Baetens","year":"2011","journal-title":"Energy Build."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Aegerter, M.A., Leventis, N., and Koebel, M.M. (2011). Aerogels Handbook, Springer Science & Business Media.","DOI":"10.1007\/978-1-4419-7589-8"},{"key":"ref_8","unstructured":"Liu, Y. (2007). Heat Transfer Mechanism and Thermal Design of Nanoporous Insulating Materials. [Ph.D. Thesis, University of Science and Technology Beijing]."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"14542","DOI":"10.1039\/C4TA02195A","article-title":"Ambient-pressure drying synthesis of large resorcinol\u2013formaldehyde-reinforced silica aerogels with enhanced mechanical strength and superhydrophobicity","volume":"2","author":"Yun","year":"2014","journal-title":"J. Mater. Chem. A"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1594","DOI":"10.1039\/C4TA05618C","article-title":"Synthesis of mechanically reinforced silica aerogels via surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization","volume":"3","author":"Maleki","year":"2015","journal-title":"J. Mater. Chem. A"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1021\/am200007n","article-title":"Tailoring mechanical properties of aerogels for aerospace applications","volume":"3","author":"Randall","year":"2011","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1036","DOI":"10.3390\/ma19051036","article-title":"Preparation of Polystyrene\/SiO2 Composite Aerogel Microspheres","volume":"19","author":"Qian","year":"2026","journal-title":"Materials"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"112766","DOI":"10.1016\/j.eurpolymj.2024.112766","article-title":"Recent advances and prospective of reinforced silica aerogel Nanocomposites and their applications","volume":"206","author":"Jadhav","year":"2024","journal-title":"Eur. Polym. J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.compositesa.2015.04.014","article-title":"Silica aerogel\/polyvinyl alcohol (PVA) insulation composites with preserved aerogel pores using interfaces between the superhydrophobic aerogel and hydrophilic PVA solution","volume":"75","author":"Kim","year":"2015","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"33296","DOI":"10.1021\/acsami.5c00606","article-title":"Recent Progress of Multifunctional Silica Aerogel Composite Materials: From Fabrication Strategies to Versatile Applications","volume":"17","author":"Li","year":"2025","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1007\/s13233-014-2006-0","article-title":"Silica aerogel\/polyimide composites with preserved aerogel pores using multi-step curing","volume":"22","author":"Kim","year":"2014","journal-title":"Macromol. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1515\/epoly-2014-0165","article-title":"Silica aerogel\/epoxy composites with preserved aerogel pores and low thermal conductivity","volume":"15","author":"Kim","year":"2015","journal-title":"e-Polymers"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1016\/j.compositesa.2019.05.004","article-title":"Super-insulating, flame-retardant, and flexible poly(dimethylsiloxane) composites based on silica aerogel","volume":"123","author":"Lee","year":"2019","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3108","DOI":"10.1002\/app.35354","article-title":"Thermal and mechanical behavior of natural rubber latex-silica aerogel film","volume":"124","author":"On","year":"2012","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"7","DOI":"10.3390\/gels8010007","article-title":"Novel Solvent\u2013Latex Mixing: Thermal Insulation Performance of Silica Aerogel\/Natural Rubber Composite","volume":"8","author":"Boonrawd","year":"2022","journal-title":"Gels"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"893","DOI":"10.1016\/j.jmrt.2025.06.067","article-title":"Tailoring thermal insulation in carbon fiber reinforced composites: Pore-preserved aerogels and thermoplastic matrix engineering","volume":"37","author":"Choi","year":"2025","journal-title":"J. Mater. Res. Technol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"131163","DOI":"10.1016\/j.colsurfa.2023.131163","article-title":"Structure and rheological properties of silica aerogel\/natural rubber latex-based slurries and composites","volume":"664","author":"Boonrawd","year":"2023","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"244","DOI":"10.1016\/j.compscitech.2018.12.027","article-title":"Flexible and coatable insulating silica aerogel\/polyurethane composites via soft segment control","volume":"171","author":"Cho","year":"2019","journal-title":"Compos. Sci. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"106108","DOI":"10.1016\/j.compositesa.2020.106108","article-title":"Investigation of the effects of silica aerogel particles on thermal and mechanical properties of epoxy composites","volume":"139","author":"Kucharek","year":"2020","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.colsurfa.2011.09.021","article-title":"Surface nanostructure of Hevea brasiliensis natural rubber latex particles","volume":"390","author":"Nawamawat","year":"2011","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_26","first-page":"6","article-title":"Structural characterization of natural rubber","volume":"50","author":"Tanaka","year":"1997","journal-title":"Kautsch. Gummi Kunststoffe"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1007\/s004250050657","article-title":"Rubber particles from four different species, examined by transmission electron microscopy and electron-paramagnetic-resonance spin labeling, are found to consist of a homogeneous rubber core enclosed by a contiguous, monolayer biomembrane","volume":"210","author":"Cornish","year":"1999","journal-title":"Planta"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"107","DOI":"10.5254\/1.3546578","article-title":"Application of the Langmuir trough to the study of rubber latex","volume":"15","author":"Wren","year":"1942","journal-title":"Rubber Chem. Technol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1900283","DOI":"10.1002\/mame.201900283","article-title":"Pre-Vulcanization of Large and Small Natural Rubber Latex Particles: Film-Forming Behavior and Mechanical Properties","volume":"304","author":"Sriring","year":"2019","journal-title":"Macromol. Mater. Eng."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2127","DOI":"10.1002\/app.29226","article-title":"Green strength of natural rubber: The origin of the stress\u2013strain behavior of natural rubber","volume":"111","author":"Amnuaypornsri","year":"2009","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"6208","DOI":"10.1021\/la981601v","article-title":"Surface Morphology of Prevulcanized Natural Rubber Latex Films by Atomic Force Microscopy:\u2009 New Insight into the Prevulcanization Mechanism","volume":"15","author":"Ho","year":"1999","journal-title":"Langmuir"},{"key":"ref_32","unstructured":"Boonrawd, C. (2023). Study of Natural Rubber Latex\/Silica Aerogel Composite for Thermal Insulation. [Ph.D. Thesis, Mahidol University]."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"126782","DOI":"10.1016\/j.ijbiomac.2023.126782","article-title":"The impact of non-deproteinization on physicochemical and biological properties of natural rubber latex for biomedical applications","volume":"253","author":"Asami","year":"2023","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.polymertesting.2015.02.011","article-title":"Investigating natural rubber composition with Fourier Transform Infrared (FT-IR) spectroscopy: A rapid and non-destructive method to determine both protein and lipid contents simultaneously","volume":"43","author":"Rolere","year":"2015","journal-title":"Polym. Test."},{"key":"ref_35","first-page":"264500","article-title":"The Effect of Vulcanization Temperature on the Properties of Natural Rubber Latex to Prepare the Suturing Training Pad","volume":"17","author":"Taksapattanakul","year":"2024","journal-title":"Recent Sci. Technol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"107050","DOI":"10.1016\/j.porgcoat.2022.107050","article-title":"Effect of Mg(OH)2\/silica composite aerogel filler on the glass transition temperature and flame retardancy of detachable polymer coatings","volume":"171","author":"Lee","year":"2022","journal-title":"Prog. Org. Coat."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2009","DOI":"10.1007\/s00289-020-03199-z","article-title":"Cure characteristics and physico-mechanical properties of natural rubber\/silica composites: Effect of natural rubber-graft-poly(2-hydroxyethyl acrylate) content","volume":"78","author":"Borapak","year":"2021","journal-title":"Polym. Bull."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"7619","DOI":"10.1021\/acsapm.6c00858","article-title":"Natural Rubber-Based Soft Robotic Gripper with Tunable Performance","volume":"8","author":"Sriring","year":"2026","journal-title":"ACS Appl. Polym. Mater."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"21060","DOI":"10.1021\/am505937p","article-title":"New Design Strategy for Reversible Plasticity Shape Memory Polymers with Deformable Glassy Aggregates","volume":"6","author":"Lin","year":"2014","journal-title":"ACS Appl. Mater. Interfaces"}],"container-title":["Gels"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2310-2861\/12\/7\/599\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T17:59:43Z","timestamp":1783533583000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2310-2861\/12\/7\/599"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,5]]},"references-count":39,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["gels12070599"],"URL":"https:\/\/doi.org\/10.3390\/gels12070599","relation":{},"ISSN":["2310-2861"],"issn-type":[{"value":"2310-2861","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,5]]}}}