Application of Liquefaction to Wood-Based Materials Hard to be Abandoned

以聚乙二醇/甘油混合物为溶剂，硫酸为催化剂，研究了杉木（Cryptomeria Japonica）的液化。结果表明，液化木材的含木量可提高50%左右。将液化后的木材与各种环氧化合物反应，形成一种新的树脂体系。通过改变液化木材与环氧化合物的比例，评价了固化树脂的粘弹性。固化后的树脂在40 ~ 70℃时普遍表现出一个较宽的玻璃化转变，表明形成了互穿聚合物网络。此外，它们的正常粘接剪切强度被认为与商用环氧树脂相同。作为一种难以废弃的木质材料，本文采用相同的方法研究了几种含聚苯乙烯和聚甲基丙烯酸甲酯的木质聚合物复合材料的液化过程。然而，这些液化并不顺利进行，因为浸渍在木材中的聚合物会阻碍溶剂与木材之间的亲和力。采用相同的溶剂和催化剂，对稻谷粉、稻秆、高山solidago altissima茎、落叶松（Larix leptolepis）、泽尔科瓦（Zelkova serrata）和银杏叶（Ginkgo biloba）作为废植物原料进行了液化研究。结果表明，稻草和树叶对液化具有普遍的抵抗性。另一方面，发现米粉和黄花茎容易液化。采用碱法预处理提高了稻草的液化性能。从米粉和一枝黄花茎中得到的产物与各种环氧化合物反应，也证明了其对环氧树脂的吸附作用。这些固化树脂在粘弹性性能的温度依赖性测量中表现出与木材树脂几乎相同的行为。

The Liquefaction of Sugi (Cryptomeria Japonica) was investigated by using polyethylene glycol/glycerol mixture as solvent and sulfuric acid as catalyst. As the results, the wood content in liquefied wood was increased up to appioximately 50%. The liquefied wood was reacted with various epoxy compounds to develop a new resin system. The viscoelastic properties of cured resins were evaluated by the changing the ration of liquefied wood to epoxv compound. The cured resins generally displayed one broad glass transition at 40-70℃, that suggested to form interpenetrating polymer networks. Further, their normal adhesive shear strength was recognized to be the same as commercial epoxy resins.As the wood-based materials hard to be abandoned, the liquefaction of several wood polymer composites (WPC), which contains polystyrene and poly(methyl methacrylate), were investigated by the same method. However, these liquefaction did not proceed well, because the polymer impregnated into wood would hinder the affinity between solvent and wood.As the waste plant materials, the liquefaction of rice flour, rice straw, stem of Solidago altissima and leaves of various trees (Larix leptolepis, Zelkova serrata and Ginkgo biloba) were investigated by using same solvent and catalyst. As the results, rice straw and tree leaves were found generally to resist to the liquefaction. On the other hand, rice flour and stem of Solidago were found to be easy to liquefy. The liquefaction of rice straw was improved by alkaline pre-treatment. The products obtained from rice flour and stem of Solidago also were shown to afford the resins by reacting with various epoxy compounds. These cured resins display almost the same behavior as those from wood in the measurement of temperature dependence of viscoelastic properties.