Guo Qiyue, He Yuan, Wu Jianyu, Ye Haichuan, You Tingting, Xu Feng
Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
Engineering Research Center of Forestry Biomass Materials and Energy, Ministry of Education, Beijing Forestry University, Beijing 100083, China.
Polymers (Basel). 2024 Aug 15;16(16):2312. doi: 10.3390/polym16162312.
It is a formidable challenge in thermoplastic/lignin composites to simultaneously boost tensile strength and elongation performance due to the rigidity of lignin. To address this issue, sodium-alginate-doped lignin nanoparticles (SLNPs) were prepared by combining solvent exchange and a coprecipitation method and used as an eco-friendly filler for poly(butylene adipate-co-terephthalate) (PBAT). The results indicated that the 1% polyanionic sodium alginate solution contributed to the formation of SLNP in lignin/THF solution. SLNP with a mean hydrodynamic diameter of ~500 nm and a Zeta potential value of -19.2 mV was obtained, indicating more hydrophobic lignin nanoparticles and a smaller number of agglomerates in SLNP suspension. Only 0.5 wt% SLNP addition improved the yield strength, tensile strength, and elongation at break by 32.4%, 31.8%, and 35.1% of the PBAT/SLNP composite films, respectively. The reinforcing effect resulted from the rigid aromatic structure of SLNP, whereas the enhanced elongation was attributed to the nanostructural feature of SLNP, which may promote boundary cracking. Additionally, the PBAT/SLNP composite films displayed excellent ultraviolet (UV) resistance with a UV shielding percentage near 100% for UVB and more than 75% for UVA, respectively. The addition of SLNP hindered water vapor, enhancing the moisture barrier properties. Overall, this study provides an effective strategy to eliminate the decrement in elongation performance for PBAT/lignin composites and suggest they are good candidates to be extensively utilized.
由于木质素的刚性，在热塑性/木质素复合材料中同时提高拉伸强度和伸长性能是一项艰巨的挑战。为了解决这个问题，通过溶剂交换和共沉淀法相结合制备了海藻酸钠掺杂的木质素纳米颗粒（SLNPs），并将其用作聚（己二酸丁二醇酯-co-对苯二甲酸丁二醇酯）（PBAT）的环保型填料。结果表明，1%的聚阴离子海藻酸钠溶液有助于在木质素/四氢呋喃溶液中形成SLNP。获得了平均流体动力学直径约为500 nm、Zeta电位值为-19.2 mV的SLNP，表明SLNP悬浮液中木质素纳米颗粒的疏水性更强，团聚体数量更少。仅添加0.5 wt%的SLNP就分别使PBAT/SLNP复合薄膜的屈服强度、拉伸强度和断裂伸长率提高了32.4%、31.8%和35.1%。增强效果源于SLNP的刚性芳香结构，而伸长率的提高归因于SLNP的纳米结构特征，这可能促进边界开裂。此外，PBAT/SLNP复合薄膜表现出优异的抗紫外线（UV）性能，对UVB的紫外线屏蔽率接近100%，对UVA的紫外线屏蔽率超过75%。SLNP的添加阻碍了水蒸气，增强了防潮性能。总体而言，本研究提供了一种有效的策略来消除PBAT/木质素复合材料伸长性能的下降，并表明它们是广泛应用的良好候选材料。
