四种植物纤维/高密度聚乙烯木塑复合材料耐海水腐蚀性能比较

为比较桉木、杨木、竹粉和稻壳为改性相的高密度聚乙烯（HDPE）基四种木塑复合材料耐海水腐蚀性能，对其进行模拟海水加速腐蚀试验，测试四种HDPE基木塑复合材料腐蚀前后力学性能和色差值，分析其腐蚀前后微观形貌和官能团变化。结果表明:模拟海水腐蚀导致四种HDPE基木塑复合材料两相结合质量变差（裂隙和空洞增多），力学性能下降，色差值变大（桉木/HDPE、杨木/HDPE和稻壳/HDPE复合材料趋于变白、变黄和变绿，竹粉/HDPE复合材料趋于变白、变蓝和变绿），羟基含量增多。模拟海水腐蚀21天，四种HDPE基木塑复合材料弯曲强度和弯曲模量降幅为:桉木/HDPE复合材料分别为12.94%和23.18%；竹粉/HDPE复合材料分别为15.45%和23.20%；稻壳/HDPE复合材料分别为18.53%和25.15%，杨木/HDPE复合材料分别为18.52%和34.21%。模拟海水腐蚀后，力学性能下降和颜色变化及断面裂隙和孔洞缺陷最少的是桉木/HDPE复合材料，最多的是杨木/HDPE复合材料。 

Comparison of seawater corrosion resistance of four types of plant fibers/high-density polyethylene composites

In order to investigate the seawater corrosion resistance of high-density polyethylene (HDPE) based wood plastic composites, four types of plant fibers (eucalyptus, poplar, bamboo, and rice husk fibers) were incorporated into HDPE. The simulated accelerated seawater corrosion test was carried on to analysis the mechanical properties, color stability, microstructure and chemical groups of four types of plant fibers/HDPE composites before and after corrosion. The results show that the accelerated seawater corrosion would result in poorer fiber/matrix bonding quality (increasing cracks and holes), mechanical properties and color stability (the color shifts towards white, yellow and green for eucalyptus/HDPE and poplar/HDPE and rice husk/HDPE composites, and the color shifts towards white, blue and green for bamboo/HDPE composites), and higher hydroxyl content. After 21 days seawater corrosion, the reductions of the flexural strength and modulus of eucalyptus/HDPE composites are 12.94% and 23.18%, respectively; for the bamboo/HDPE composites, the reductions are 15.45% and 23.20%, respectively; for the rice husk/HDPE composites, the reductions are 18.53% and 25.15%, respectively; and for the poplar/HDPE composites, the reductions are 18.52% and 34.21%, respectively. The eucalyptus/HDPE and poplar/HDPE composites present the lowest and highest degradation (such as mechanical loss, color fading and interfacial debonding) after corrosion, respectively.