Abstract The objectives of this study were (i) to synthesize bio-oil-based phenol–formaldehyde resin to be used for the wood products industry, and (ii) to investigate the effect of phenol substitution (molar-based vs. weight-based) with bio-oil on the properties of resulting PF resin. Bio-oil was produced by hydrothermal liquefaction (HTL) process using sweetgum hardwood, and utilized as a bio-based phenolic feedstock as an alternative for petroleum-based phenol in the synthesis of PF resin. Phenol was substituted with bio-oil (both as weight- and molar-based). The resulting PF resin was noted as BPF-W and BPF-M when bio-oil was used to replace 50% of phenol in weight- and molar-based, respectively, and then compared with neat PF resin in terms of free formaldehyde content, gel time, pH of the resin, solid content, bond strength and thermal stability. Results showed that BPF-M resin had less free formaldehyde content and longer gel time than BPF-W resin. No significant difference in pH and solid content was observed between bio-oil-based PF resins. Moreover, molar-based substitution resulted in a resin with higher bonding strength than that of weight-based substitution, and both BPF-W and BPF-M showed higher bonding strength then neat PF resin. TGA analysis of the resin revealed that substitution of phenol with bio-oil lowered the thermal stability of bio-oil derived PF resins. However, molar-based substitution of phenol with bio-oil could enhance the thermal stability.

中文翻译：

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生物油基酚醛树脂：苯酚与生物油的重量和摩尔取代比较

摘要 本研究的目的是 (i) 合成用于木制品工业的生物油基酚醛树脂，以及 (ii) 研究苯酚取代的影响（摩尔基与重量基) 与生物油对所得 PF 树脂的性能的影响。生物油是使用甜胶硬木通过水热液化 (HTL) 工艺生产的，并用作生物基酚类原料，在 PF 树脂的合成中作为石油基苯酚的替代品。苯酚被生物油取代（以重量和摩尔为基础）。当使用生物油分别取代 50% 的苯酚时，所得 PF 树脂分别记为 BPF-W 和 BPF-M，分别以重量和摩尔为基础，然后与纯 PF 树脂的游离甲醛含量进行比较，凝胶时间、树脂的 pH 值、固体含量、粘合强度和热稳定性。结果表明，BPF-M树脂比BPF-W树脂游离甲醛含量少，凝胶时间长。在基于生物油的 PF 树脂之间没有观察到 pH 值和固体含量的显着差异。此外，基于摩尔的取代导致树脂比基于重量的取代具有更高的粘合强度，并且 BPF-W 和 BPF-M 都显示出比纯 PF 树脂更高的粘合强度。树脂的 TGA 分析表明，用生物油取代苯酚会降低生物油衍生的 PF 树脂的热稳定性。然而，用生物油基于摩尔的苯酚取代可以提高热稳定性。在基于生物油的 PF 树脂之间没有观察到 pH 值和固体含量的显着差异。此外，基于摩尔的取代导致树脂比基于重量的取代具有更高的粘合强度，并且 BPF-W 和 BPF-M 都显示出比纯 PF 树脂更高的粘合强度。树脂的 TGA 分析表明，用生物油取代苯酚会降低生物油衍生的 PF 树脂的热稳定性。然而，用生物油基于摩尔的苯酚取代可以提高热稳定性。在基于生物油的 PF 树脂之间没有观察到 pH 值和固体含量的显着差异。此外，基于摩尔的取代导致树脂比基于重量的取代具有更高的粘合强度，并且 BPF-W 和 BPF-M 都显示出比纯 PF 树脂更高的粘合强度。树脂的 TGA 分析表明，用生物油取代苯酚会降低生物油衍生的 PF 树脂的热稳定性。然而，用生物油基于摩尔的苯酚取代可以提高热稳定性。树脂的 TGA 分析表明，用生物油取代苯酚会降低生物油衍生的 PF 树脂的热稳定性。然而，用生物油基于摩尔的苯酚取代可以提高热稳定性。树脂的 TGA 分析表明，用生物油取代苯酚会降低生物油衍生的 PF 树脂的热稳定性。然而，用生物油基于摩尔的苯酚取代可以提高热稳定性。