A Novel Soybean Flour-based Sizing and Strength Additive for Replacing the Daily Food Starch in the Papermaking Process

尽管日常膳食对淀粉的需求量很大，但每年仍有数百万吨淀粉被用作纸张浆料和干强度添加剂。这一点很重要，因为由于人口增长，全球粮食需求正在增加。同样，造纸工业中使用的数百万吨石油基纸干强剂引起了对环境的关注，促使人们努力开发替代品。与淀粉、变性淀粉或石油基强度剂相比，大豆粉是一种廉价的复合多糖，可能是一种合适的替代品。但使用大豆粉的主要问题是，它会引起细菌消化问题，产生难闻的气味和污垢，这是造纸工业使用时需要考虑的重要问题。该项目的目标是通过一种环境可持续的化学改性来阻止大豆粉的细菌分解，从而有利于纸张和纸包装行业的纸张施胶/强度应用。本工作的重点研究活动包括：1)通过特定的化学途径改性合成季正电功能化大豆粉，改性大豆粉最终表现出克服细菌分解的抗菌活性；2)研究改性大豆粉和未改性大豆粉的生物分解，以确定其抗菌性能；3)对改性大豆粉和改性大豆粉处理浆纸的物理性能和抗菌活性进行了表征。目标是将这些材料用作纸张和纸包装工业中淀粉基施胶/强度剂的替代品。提出的改性大豆粉具有解决低成本、高性能、可生物降解和食品级无毒纸制品要求的潜力。此外，该项目有可能导致替代造纸工业中使用的聚丙烯酰胺等不可生物降解和污染的石油基纸干强剂，从而解决环境和健康问题。研究生和本科生都将成为项目团队的成员。此外，K-12外展计划是整个项目可交付成果的一部分。该项目方法是基于开发一种创新的反应机制，将季铵盐引入大豆粉中，使功能化大豆粉具有杀菌活性并克服生物诱导分解。初步结果支持这样的假设，即在大豆粉中引入这种季铵盐在阻止生物消化和抑制大豆粉被细菌、霉菌和真菌污染方面起着关键作用。这一假设将通过测试反应条件来进一步检验，以提高目标性能。用FTIR、NMR、XPS、SEM、TGA、DSC、XRD等分析改性大豆粉的改性和热稳定性。交联改性大豆粉中的阳离子电荷将由电荷分析仪测定，抗菌活性将通过标准AATCC 100和FTTS- FA-002测试方法进行评估。豆粉和季阳离子带功能化豆粉的生物消化将通过ASTM测试方法进行评估。初步实验结果表明，四元阳离子带电荷功能化大豆粉显著提高了其自身和与大小纸张的抗菌性能，并显著提高了纸张的抗拉强度。这项工作不仅将探讨化学转化，还将探索一系列反应物和交联剂，并优化反应条件，以制造功能性和应用动机的抗菌豆粉，以潜在地取代日常食品淀粉。同样，初步结果表明，功能化大豆粉可以作为纸张表面施胶剂，改变纸张的吸收性能，提高施胶纸的强度，有可能取代淀粉基施胶剂。该项目将进一步证实这些初步结果。对改性豆粉处理浆纸的吸收率、强度、刚度、印刷适性等性能进行评价，并与淀粉处理浆纸性能进行比较。对改性豆粉处理浆纸的抗菌性能进行评价，以确定其对豆粉细菌分解的抑制作用。此外，改性大豆粉将与纸浆混合制成添加剂处理的纸张，以表征其物理性能，特别是与商业石油基强度添加剂（聚丙烯酰胺）处理的纸张相比的强度。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Millions of tons of starches are used as a paper sizing and dry strength additive every year despite the fact that starch is typically in high demand for daily meals. This is important to note because global food demand is increasing due to population growth. Similarly, millions of tons of petroleum-based paper dry strength agents used in the paper making industry have raised environmental concerns, motivating efforts toward developing alternatives. Soybean flour is a cheap complex polysaccharide compared to starch, modified starches, or petroleum-based strength agents, and may be a suitable substitute. But the main problem associated with using soybean flour is that it poses a bacterial digestion problem that can produce bad odors and fouling, vital issues to consider for use in paper industries. The goal of this project is to stop the bacterial decomposition of soybean flour by an environmentally sustainable chemical modification in order to benefit paper sizing/strength applications in the paper and paper packaging industries. The key research activities of this work include: 1) synthesis of quaternary positively charged functionalized soybean flour by a specific chemical pathway modification in which modified soybean flour will ultimately demonstrate the antimicrobial activity to overcome bacterial decomposition, 2) investigation of the biological decomposition of modified soybean flour and unmodified soybean flour to determine antimicrobial performance, and 3) characterization of the physical properties and antimicrobial activities of the modified soybean flour and modified soybean flour-treated sized paper. The goal is for these materials to be used as an alternative to starch-based sizing/strength agents in the paper and paper packaging industries. The proposed modified soybean flour has the potential to address low-cost, high-performance, biodegradable, and food-grade requirements for non-toxic paper products. Additionally, the project holds the potential to lead to the replacement of non-biodegradable and polluting petroleum-based paper dry-strength agents such as polyacrylamide used in the paper industries and thus address environmental and health concerns. Both graduate and undergraduate students will be members of the project team. In addition, K-12 outreach is planned as part of the total project deliverables.The project approach is based on exploiting an innovative reaction mechanism for introducing a quaternary cationic charge into soybean flour such that the functionalized soybean flour will exhibit bactericidal activity and overcome biologically-induced decomposition. Preliminary results support the hypothesis that the introduction of this quaternary cationic charge in soybean flour plays a key role in stopping biological digestion and inhibiting soybean flour contamination by bacteria, mold, and fungi. This hypothesis will be further examined by testing reaction conditions in pursuit of enhancing targeted performance. Modified soybean flour will be analyzed by FTIR, NMR, XPS, SEM, TGA, DSC, and XRD to confirm modification and thermal stability. Cationic charges in cross-linked modified soybean flour will be determined by a charge analyzer and antimicrobial activity will be evaluated by standard AATCC 100 and FTTS- FA-002 test methods. The biological digestion of soybean flour and quaternary cationic charged-functionalized soybean flour will be evaluated by ASTM test methods. Preliminary lab results have shown that the quaternary cationic charged-functionalized soybean flour significantly enhances the antimicrobial properties of itself and with a sized paper sheet as well as significantly contributing to the tensile strength of paper. The work will probe not only the chemical transformations but also explore a range of reactants and crosslinking agents, and optimize reaction conditions to make functionally competent and application-motivated antimicrobial soybean flours to potentially replace daily food starch. Likewise, preliminary results indicate that the functionalized soybean flour can be used as a surface sizing agent in paper to change absorption properties and increase the strength of sized paper, potentially replacing starch-based sizing agents. The project will further confirm these preliminary results. The absorption, strength, stiffness, printability, and other properties of modified soybean flour-treated sized paper will be evaluated and compared with starch-treated sized paper properties. The antimicrobial properties of modified soybean flour-treated sized paper will be evaluated to confirm the inhibition of bacterial decomposition of soybean flour. Additionally, modified soybean flour will be blended with pulp slurry to fabricate additive-treated paper sheets to characterize physical properties, especially strength compared to commercial petroleum-based strength additive (polyacrylamide)-treated papers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.