Increasing prices of petrochemical resins and possible harmful formaldehyde emissions from conventionally produced wood composites have resulted in increased interest in enzymatic binder systems as environmentally friendly alternatives for gluing lignocellulosic products. In this study, laccase mediator systems (LMSs) were used to activate lignin on wood fiber surfaces in the pilot-scale production of medium-density fiberboard (MDF) using a dry process. Three different mediators were applied: 4-hydroxybenzoic acid (HBA), 1-hydroxybenzotriazole (HBT), and acetosyringone (AS) of which HBA performed best. The mechanical properties of the manufactured boards produced with thermomechanical pulp (TMP) fibers, laccase, and HBA fulfilled all required European standards for wood-based panels. Oxygen consumption rates of the different LMSs and (13)C NMR spectroscopy results for treated TMP fibers were obtained for qualitative and quantitative analysis of lignin activation. The results show that reactions were most effective within the first 30 min of incubation. Oxygen consumption was fastest and highest for the LMS using HBA. (13)C NMR spectroscopy indicated the highest decrease of aromatic groups in the wood fiber lignin with this LMS. The data correlated well with the quality of the MDF. The required enzymatic reaction times allowed direct integration of the LMS into standard MDF production techniques. The results indicate that application of LMSs has a high potential for environmentally friendly MDF production.

中文翻译：

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漆酶介体系统，用于在中试规模上以生态友好的方式生产中密度纤维板（MDF）：反应机理的理化分析。

石油化学树脂的价格上涨以及常规生产的木质复合材料可能产生的有害甲醛排放，已引起人们对酶促粘合剂体系的兴趣日益浓厚，作为胶粘木质纤维素产品的环保替代品。在这项研究中，漆酶介体系统（LMS）用于在干法中密度纤维板（MDF）的中试规模生产中激活木质纤维表面的木质素。应用了三种不同的介质：4-羟基苯甲酸（HBA），1-羟基苯并三唑（HBT）和乙酰丁香酮（AS），其中HBA表现最佳。用热机械浆粕（TMP）纤维，漆酶和HBA生产的人造板的机械性能满足了人造板所有欧洲要求的标准。获得了不同LMS的耗氧率和经处理的TMP纤维的（13）C NMR光谱结果，用于木质素活化的定性和定量分析。结果表明，反应在孵育的前30分钟内最有效。使用HBA的LMS耗氧最快，最高。（13）C NMR光谱表明，使用该LMS，木纤维木质素中的芳族基团减少最多。数据与MDF的质量密切相关。所需的酶促反应时间可将LMS直接整合到标准MDF生产技术中。结果表明，LMS的应用在环境友好的MDF生产中具有很高的潜力。结果表明，反应在孵育的前30分钟内最有效。使用HBA的LMS耗氧最快，最高。（13）C NMR光谱表明，使用该LMS，木纤维木质素中的芳族基团减少最多。数据与MDF的质量密切相关。所需的酶促反应时间可将LMS直接整合到标准MDF生产技术中。结果表明，LMS的应用在环境友好的MDF生产中具有很高的潜力。结果表明，反应在孵育的前30分钟内最有效。使用HBA的LMS耗氧最快，最高。（13）C NMR光谱表明，使用该LMS，木纤维木质素中的芳族基团减少最多。数据与MDF的质量密切相关。所需的酶促反应时间可将LMS直接整合到标准MDF生产技术中。结果表明，LMS的应用在环境友好的MDF生产中具有很高的潜力。数据与MDF的质量密切相关。所需的酶促反应时间可将LMS直接整合到标准MDF生产技术中。结果表明，LMS的应用在环境友好的MDF生产中具有很高的潜力。数据与MDF的质量密切相关。所需的酶促反应时间可将LMS直接整合到标准MDF生产技术中。结果表明，LMS的应用在生产中密度纤维板方面具有很高的潜力。