Creation of biomimetic composites using matrix resins derived from wood biomass

以间苯二酚液化木材为树脂前驱体，合成了木质热固性环氧树脂。首先，木粉通过与间苯二酚在耐压管中的反应进行液化。试管中的黑色浆料被认为是合成环氧树脂的前驱体，因为反应的化合物中含有大量的羟基，因为反应中心来自木材和溶剂。其次，对酚羟基进行缩水甘油醚化反应，合成了木质环氧树脂。因此，树脂的环氧官能度将反映液化木材中酚羟基的浓度。木质固化环氧树脂的弹性模量和弯曲强度与商品化双酚A型环氧树脂相当。此外，木基液态环氧树脂的粘度足够低，可以浸渍在增强纤维中。因此，以可再生生物质资源为原料，由木基环氧树脂和亚麻纤维复合而成的新型绿色复合材料得到了成功的应用。木质环氧树脂对亚麻纤维表面具有良好的粘接性能，是一种很有潜力的绿色复合材料基质树脂。亚麻纤维增强木质环氧基复合材料的刚性与相同纤维增强的商品环氧基复合材料的刚性相当。

Wood-based thermoset epoxy resins were newly synthesized from resorcinol-liquefied wood as a resin precursor. Firstly, wood meal was liquefied by the reaction with resorcinol in a pressure-proof tube. The black paste in the tube was considered as a precursor for synthesizing the epoxy resin, because the reacted compound would include considerable amount of hydroxyl groups as reactive sites originated from the wood and the solvents. Next, the glycidyl etherification for the phenolic-OH groups was conducted and the wood-based epoxy resins were synthesized. The epoxy functionality of the resins would therefore reflect the concentration of phenolic-OH groups of the liquefied-wood. The modulus of elasticity and the flexural strength of the wood-based cured epoxy resins were equivalent to those of commercial-based bisphenol-A type epoxy resin. Also, the viscosity of the wood-based liquid epoxy resins was low enough to impregnate among reinforcing fibers. Therefore, new green composites from the renewable biomass resources, composed of the wood-based epoxy matrix resins and flax fibers, were successfully fabricated. The wood-based epoxy resins had good adhesive property to the surface of flax fibers, which indicates the high potential as matrix resins for green composites. The stiffness of the flax fiber reinforced wood-based epoxy composites were equivalent to those of the same fiber reinforced commercial-based epoxy composites.