不同多巴胺添加量对竹粉/高密度聚乙烯复合材料性质的影响

Properties of Bamboo Powder Treated by Different Dosages of Dopamine/High-density Polyethylene Composites

受海洋贝类对固体表面超强黏附现象的启发,采用盐酸多巴胺对竹塑复合材料进行增强改性。分别使用多巴胺添加量为0、0.25%、0.50%、1.00%处理了毛竹竹粉,制备出竹粉/高密度聚乙烯复合材料D0、D0.25、D0.50、D1.00。竹粉与复合材料的分析方法包括傅里叶变换衰减全反射红外分析、X射线衍射法、物理力学测试、SEM和接触角法。结果显示:多巴胺可以作为竹粉/高密度聚乙烯体系有效的表面改性剂,不同多巴胺添加量改性后材料的弯曲强度和拉伸强度都有提高。适合的多巴胺添加量是0.50%,材料的拉伸强度和弯曲模量分别提升7.74%、27.78%。不同多巴胺添加量处理的竹粉具备相同结晶结构。多巴胺添加量不同,一定程度改变了竹粉的分子结构。SEM分析显示,D0.50中竹粉分散均匀,与聚乙烯结合最为紧密。多巴胺抑制了竹粉的亲水性能,使得改性竹粉水接触角增大。

Inspired by strong adhesion of shellfish to solid surface,we used the dopamine hydrochloride to enhance bamboo plastic composites.Moso bamboo powder was treated with 0,0.25%,0.5%and 1%dopamine,and they were used to prepare bamboo powder/high-density polyethylene composites D0,D0.25,D0.5 and D1,respectively.For bamboo powder and composites,analysis methods included attenuated total reflection,X-ray diffraction,physical-mechanical testing,and scanning electron microscopy and contact angle.Bamboo powder D0,D0.25,D0.5,and D1 had the same crystalline structure.Appropriate dopamine can reduce the surface polarity of bamboo powder while maintaining the original mechanical strength.The infrared spectra proved that dopamine reacted with bamboo powder to form a dark covering film.At different dosages of dopamine,the molecular structure of bamboo powder was changed to a certain extent.Dopamine can be used as an effective surface modifier for bamboo powder/high-density polyethylene composites.The bending strength and tensile strength of bamboo fiber modified with different dosages of dopamine were improved.D0.5 was the appropriate dosage of dopamine for tensile strength and bending modulus,which increased by 7.74%and 27.78%,respectively.Tensile fracture surface morphology of composites showed that bamboo powder in composites D0.5 had even dispersion,the highest interfacial adhesion with high-density polyethylene,and no obvious gap at interface.Dopamine inhibits the hydrophilic property of bamboo powder and increases the water contact angle of modified bamboo powder.