Three kinds of tree bark extractives from trembling aspen (Populus tremuloides) (AE), lodgepole pine (Pinus contorta) (LE), and western red cedar (Thuja plicata) (RE) were produced and used as antioxidants. The antioxidation activities of those extractives were evaluated and compared with commercial antioxidant butylated hydroxytoluene (BHT). The obtained extractives were applied as natural photostabilizers to produce wood flour/polypropylene (WF/PP) composites at an addition level of 2 wt%. The composites were subjected to QUV accelerated weathering tester for a total of 1200 h. The changes in surface color, surface morphology, and surface chemistry of composites were investigated during the exposure. The results showed that all bark extractives alleviated the photodegradation of composites successfully. Among them, RE was proved to be the most effective. It exhibited excellent UV absorption and similar free-radical inhibition ability compared with BHT. Consequently, composites containing RE exhibited less discoloration, less severe surface cracking, and less changes in surface chemistry during the whole weathering process. Overall, these results revealed that RE had great potential as a natural photostabilizer in polymer systems.

颤抖的白杨（Populus tremuloides）（AE），黑松（Pinus contorta）（LE）和西部红柏（Thuja plicata）的三种树皮提取物）（RE）被生产并用作抗氧化剂。评估了这些提取物的抗氧化活性，并与市售抗氧化剂丁基化羟基甲苯（BHT）进行了比较。将获得的提取物用作天然光稳定剂，以2％（重量）的添加量生产木粉/聚丙烯（WF / PP）复合材料。使复合材料经受QUV加速耐候性测试仪共1200小时。在暴露过程中研究了复合材料的表面颜色，表面形态和表面化学变化。结果表明，所有树皮提取物均能成功减轻复合材料的光降解。其中，RE被证明是最有效的。与BHT相比，它具有出色的紫外线吸收和类似的自由基抑制能力。所以，含稀土的复合材料在整个风化过程中均表现出较少的变色，较小的表面开裂和较小的表面化学变化。总体而言，这些结果表明，稀土在聚合物体系中具有作为天然光稳定剂的巨大潜力。