Anjum Sobia, Parks Kendall, Clark Kaylin, Parker Albert, Heveran Chelsea M, Gerlach Robin
Department of Chemical & Biological Engineering, Montana State University, Bozeman, USA.
Center for Biofilm Engineering, Montana State University, Bozeman, USA.
Sci Rep. 2025 Jan 27;15(1):3453. doi: 10.1038/s41598-024-84087-8.
Common adhesives for nonstructural applications are manufactured using petrochemicals and synthetic solvents. These adhesives are associated with environmental and health concerns because of their release of volatile organic compounds (VOCs). Biopolymer adhesives are an attractive alternative because of lower VOC emissions, but their strength is often insufficient. Existing mineral fillers can improve the strength of biopolymer adhesives but require the use of crosslinkers that lower process sustainability. This work introduces a novel approach to strengthen biopolymer adhesives through calcium carbonate biomineralization, which avoids the need for crosslinkers. Biomineral fillers produced by either microbially or enzymatically induced calcium carbonate precipitation (MICP and EICP, respectively) were precipitated within guar gum and soy protein biopolymers. Both, MICP and EICP, increased the strength of the biopolymer adhesives. The strength was further improved by optimizing the concentrations of bacteria, urease enzyme, and calcium. The highest strengths achieved were on par with current commercially available nonstructural adhesives. This study demonstrates the feasibility of using calcium carbonate biomineralization to improve the properties of biopolymer adhesives, which increases their potential viability as more sustainable adhesives.
用于非结构应用的常见粘合剂是使用石化产品和合成溶剂制造的。由于这些粘合剂会释放挥发性有机化合物（VOCs），因此与环境和健康问题相关。生物聚合物粘合剂因其较低的VOC排放量而成为有吸引力的替代品，但其强度往往不足。现有的矿物填料可以提高生物聚合物粘合剂的强度，但需要使用降低工艺可持续性的交联剂。这项工作引入了一种通过碳酸钙生物矿化来增强生物聚合物粘合剂的新方法，该方法无需使用交联剂。通过微生物诱导或酶诱导碳酸钙沉淀（分别为MICP和EICP）产生的生物矿物填料在瓜尔胶和大豆蛋白生物聚合物中沉淀。MICP和EICP都提高了生物聚合物粘合剂的强度。通过优化细菌、脲酶和钙的浓度，强度进一步提高。所达到的最高强度与目前市售的非结构粘合剂相当。这项研究证明了使用碳酸钙生物矿化来改善生物聚合物粘合剂性能的可行性，这增加了它们作为更可持续粘合剂的潜在可行性。
