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Sustainability of the adhesives prepared from fossil-based materials has become a growing concern. Thus, replacement of petroleum-based materials by ones derived from renewable resources is pursued as a sustainable strategy for reducing their carbon footprint. Biobased latexes can be widely used as waterborne adhesives if their performance and properties are competitive to those currently available in the market. This work aims to evaluate the performance of latex adhesives with higher biobased content recently developed in our group. For this purpose, plant oil-based vinyl monomers HOSBM and CMM (derived from high oleic soybean oil and camelina oil, respectively) in combination with methyl methacrylate (MMA) and butyl acrylate (BA) were copolymerized using miniemulsion to yield latexes to be tested as adhesives. The MMA (“rigid” fragment) content was kept at 55 wt%, while BA (within remaining 45 wt% of the “soft” fragments) has been gradually replaced by either CMM or HOSBM. The effect of partial substitution of the BA by CMM or HOSBM on adhesive properties was assessed using peel testing (ASTM D 1876-08) on the multiple substrates. Presence of plant oil-based fragments in latex copolymers improves adhesives peel strength on most substrates. Plant oil-based latexes with the maximum content of CMM or HOSBM (up to 45wt %) and their optimal adhesive performance were determined on various carpet and paperboard substrates. Additionally, Life Cycle Assessment (LCA) method was used as a tool to evaluate the environmental performance of the synthesized latex adhesives as well as identify the hotspots in the synthesis of these plant-derived adhesives in their early design stages. LCA of plant oil-based monomers can explain to which extent the sustainability of the biobased latex adhesives can be improved. The authors thank the NSF Industry and University Cooperative Research Center for Bioplastic and Biocomposites for financial support. Thanks to NSF CB2 (1916564)
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This content will become publicly available on February 1, 2026
Hydrothermal Liquefied Bio-Oil from Municipal Sewage Sludge as a Reactive Filler in Polymeric Diphenylmethane Diisocyanate (p-MDI) Wood Adhesives
The growing environmental concerns associated with petrochemical-based adhesives have driven interest in sustainable alternatives. This study investigates the use of bio-oil, derived from municipal sewage sludge (MSS) through hydrothermal liquefaction (HTL), as a reactive filler in polymeric methylene diphenyl diisocyanate (pMDI) wood adhesives. The bio-oil, rich in hydroxyl and carbonyl functional groups, was characterized using FTIR (Fourier transform infrared spectroscopy), elemental analysis, and NMR (nuclear magnetic resonance). These functional groups interact with the isocyanate groups of pMDI, enabling crosslinking and enhancing adhesive performance. Various MSS bio-oil and pMDI formulations were evaluated for tensile shear strength on Southern yellow pine veneers under dry and wet conditions. The formulation with a 1:4 bio-oil to pMDI weight ratio exhibited the best performance, achieving tensile shear strengths of 1.96 MPa (dry) and 1.66 MPa (wet). Higher bio-oil content led to decreased adhesive strength, attributed to reduced crosslinking and increased moisture sensitivity. This study demonstrates the potential of MSS-derived bio-oil as a sustainable additive in pMDI adhesives, offering environmental benefits without significantly compromising adhesive performance and marking a step toward greener wood adhesive solutions.
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- Award ID(s):
- 1735971
- PAR ID:
- 10645988
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Sustainability
- Volume:
- 17
- Issue:
- 3
- ISSN:
- 2071-1050
- Page Range / eLocation ID:
- 1318
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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