Ostendorf Kolja, Ahrens Christian, Beulshausen Arne, Tene Tayo Jean Lawrence, Euring Markus
Department of Forest Botany and Tree Physiology, Georg-August University Goettingen, 37073 Göttingen, Germany.
Polymers (Basel). 2021 Mar 30;13(7):1088. doi: 10.3390/polym13071088.
The thermal insulation of buildings using wood fiber insulation boards (WFIBs) constitutes a positive contribution towards climate change. Thereby, the bonding of wood fibers using mainly petrochemical-based resins such as polymeric diphenylmethane diisocyanate (pMDI) is an important measure to meet required board properties. Still there is a need to reduce or partial substitute the amount of these kinds of resins in favor of a greener product. This study therefore focusses on the feasibility of reducing the amount of pMDI by 50% through the addition of 1% BioPiva 395 or Indulin as two types of softwood Kraft-Lignin and lignin rich canola hulls together with propylene carbonate as a diluent. A panel density of 160 kg/m and a thickness of 40 mm was aimed. The curing of these modified pMDI was investigated by using two types of techniques: hot-steam (HS) and innovative hot-air/hot-steam-process (HA/HS). The WFIBs were then tested on their physical-mechanical properties. The equilibrium moisture content (EMC) was determined at two different climates. An exemplary investigation of thermal conductivity was conducted as well. The WFIBs did undergo a further chemically based analysis towards extractives content and elemental (C, N) composition. The results show that it is feasible to produce WFIBs with lower quantities of pMDI resin and added lignin with enhanced physical-mechanical board properties, which were lacking no disadvantages towards thermal conductivity or behavior towards moisture, especially when cured via HA/HS-process.
使用木纤维保温板（WFIBs）对建筑物进行保温有助于应对气候变化。因此，主要使用基于石化的树脂（如聚合二苯基甲烷二异氰酸酯（pMDI））来粘结木纤维是满足板材所需性能的一项重要措施。然而，仍有必要减少或部分替代这类树脂的用量，以生产更环保的产品。因此，本研究着重探讨通过添加1%的BioPiva 395或Indulin（两种软木硫酸盐木质素和富含木质素的油菜籽壳）以及碳酸丙烯酯作为稀释剂，将pMDI的用量减少50%的可行性。目标是生产出面板密度为160 kg/m³且厚度为40 mm的板材。采用两种技术对这些改性pMDI的固化情况进行了研究：热蒸汽（HS）和创新的热风/热蒸汽工艺（HA/HS）。然后对WFIBs的物理力学性能进行了测试。在两种不同气候条件下测定了平衡含水率（EMC）。还对导热系数进行了示例性研究。对WFIBs的提取物含量和元素（C、N）组成进行了进一步的化学分析。结果表明，减少pMDI树脂用量并添加木质素以提高板材物理力学性能是可行的，且对导热系数或防潮性能没有不利影响，特别是通过HA/HS工艺固化时。
