ABSTRACT 1,3-dimethyl-4,5-dihydroxyethyleneurea (DDHEU) and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) were used as the binders in 3-mm high density fiberboard (HDF) manufacturing. The studies focus on the physical and mechanical properties of boards bonded with DDHEU or DMDHEU as a potential substitute for typically used urea-formaldehyde (UF) resins. The adhesive loads were 8% or 12%. The UF-bonded boards of same resin load were used as the controls. Applied pressing time ranged between 4 and 5 minutes. The results indicate that the use of DDHEU or DMDHEU as binders enhanced physical and mechanical properties of the boards. It was found that properly set pressing scheme and resin type allowed produce DDHEU- and DMDHEU-bonded HDF that exhibited comparable or superior performance when compared to the UF-bonded reference series and complied with European Standards. The best performing boards exhibited internal bond 1.3 MPa, modulus of elasticity 9656 MPa, modulus of rupture 56.5 MPa, thickness swelling 14% and formaldehyde release below 3.0 mg/m2h. Due to low reactivity of DDHEU and DMDHEU at temperatures below 160°C, the approach is effective for thin boards only.

中文翻译：

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1,3-二羟甲基-4,5-二羟基亚乙基脲（DMDHEU）粘合的薄高密度纤维板的物理机械性能

摘要 1,3-二甲基-4,5-二羟基亚乙基脲 (DDHEU) 和 1,3-二羟甲基-4,5-二羟基亚乙基脲 (DMDHEU) 被用作 3 毫米高密度纤维板 (HDF) 制造中的粘合剂。这些研究侧重于用 DDHEU 或 DMDHEU 粘合的板的物理和机械性能，作为通常使用的脲醛 (UF) 树脂的潜在替代品。粘合剂负载为8%或12%。相同树脂负载的超滤粘合板用作对照。施加的按压时间在 4 到 5 分钟之间。结果表明，使用 DDHEU 或 DMDHEU 作为粘合剂增强了板的物理和机械性能。结果发现，正确设置压制方案和树脂类型可以生产 DDHEU 和 DMDHEU 粘合的 HDF，与 UF 粘合参考系列相比，它们表现出相当或优越的性能，并符合欧洲标准。表现最佳的板材表现出内部粘合 1.3 MPa、弹性模量 9656 MPa、断裂模量 56.5 MPa、厚度膨胀 14% 和甲醛释放量低于 3.0 mg/m2h。由于 DDHEU 和 DMDHEU 在低于 160°C 的温度下反应性低，该方法仅对薄板有效。