表面改性对竹纤维与聚丙烯纤维混杂毡平铺复合材料湿热老化影响

Effect of Surface Modification on Hygrothermal Ageing Behavior of Bamboo Fiber and Polypropylene Fiber Hybrid Composite

采用碱处理以及碱-偶联剂处理竹纤维,利用非织造和热压工艺制备了竹纤维(BF)与聚丙烯纤维(PP)混杂毡平铺复合材料。研究了改性前后竹纤维与聚丙烯纤维混杂毡平铺复合材料的湿热老化行为的变化,并用SEM研究了复合材料界面结合状况。结果表明:竹纤维与聚丙烯纤维混杂毡平铺复合材料的吸湿规律符合Fick吸湿定律,和竹纤维含量无关,复合材料的吸湿行为不仅与竹纤维含量有关,还与材料内部孔洞密切相关。湿热老化对复合材料拉伸性能影响不显著,经过碱处理或者碱-偶联剂处理后,竹纤维与聚丙烯纤维混杂毡平铺复合材料耐湿热老化性能有较明显的提升效果,综合考虑湿热老化后复合材料的性能,碱-偶联剂处理后复合材料耐湿热老化性能最优,当湿热老化60 d后,复合材料的弯曲和拉伸强度分别为60.55、33.10 MPa,较未处理分别提高了49.51%、18.06%,弯曲和拉伸模量分别为3.91、3.58 GPa,较未处理分别提高了64.7%、7.28%。SEM结果显示:经过碱-偶联剂处理后,竹纤维与聚丙烯树脂之间的黏结得到了提升,复合材料内部孔隙减少,阻碍了水分在材料内的扩散,从而提升了复合材料的耐湿热老化性能。

Alkali treatment and alkali-silane treatment were used to modify bamboo fiber, bamboo fiber（BF） and polypropylene fiber （PP） hybrid composite were manufactured by nonwoven technology and compression moulding. Hygrothermal ageing behavior of untreated and treated BF/PP hybrid composite were investigated. SEM was used to describe composite interface bonding conditions. The results revealed that the evolution of water absorption for BF/PP hybrid composite had appeared to be Fiekian＇ s law, it had not been and relevanted to the content of bamboo fiber. The moisture absorption behavior of the composite was not only related to the content of bamboo fiber, but also with the inner voids of the composite. Effects of hygrotbermal aging on the tensile properties of composite were not significant. After alkali treatment or alkali-silane treatment,the hygrothermal properties of BF/PP hybrid composite had an obvious promotion. Considering the properties of composite, after alkali-silane treatment, BF/PP composite attained optimal level. After 60 days ageing, flexrual and tensile strength of the composite reinforced by alkali-silane treatment bamboo fiber were 60.55 and 33.10 MPa,which compared with the untreated increased by 49.51% and 18.06% respectively. And the flexrual and tensile modulus of the composite reinforced by alkali-silane treatment bamboo fiber were 3.91 and 3.58 GPa, improved by 64. 7% and 7.28% compared with untreated, respectively. SEM results showed that after alkali-silane treatment, bonding between the fibres and matrix was improved, and the voids in composite was reduced, which hinder the diffusion of moisture in the materials, then increased hygrothermal properties of composite materials.