桉木/PLA复合材料界面改性方法及其性能研究

Study on interfacial modification method and property of eucalyptus/PLA composite

以桉木为填料,聚乳酸(PLA)为基体,应用模压成型工艺制备桉木/PLA复合材料,通过添加壳聚糖、硅烷偶联剂及进行NaOH处理改善其界面相容性,进一步分析木塑复合材料的吸水吸湿性及力学性能,从而确定最优的改性方法。结果表明:对于壳聚糖,其含量为2%左右时复合材料的整体力学性能相对较好,此时接触角相对较大,材料相对比较疏水,而吸水率也相对较小。而对于硅烷偶联剂,其能较为明显地提高材料的力学性能,当加入6%硅烷时,材料的力学性能相对较好,此时拉伸强度有较大幅度提升,值为19.68MPa,而弯曲强度相比无偶联剂时相应提高,洛氏硬度也相对较高,其值为138HRB。4%氢氧化钠处理的材料力学性能较好,且此时吸水率相对会较小。

Eucalyptus was used as filler and polylactic acid(PLA) as matrix to prepare eucalyptus/PLA composite by molding process.The interface compatibility was improved by adding chitosan,silane coupling agent and NaOH treatment.The water absorption and mechanical properties of the wood plastic composite were further analyzed to determine the optimal modification method.The final experimental results shown that:for chitosan,when its content was about 2%,the overall mechanical properties of the composite were relatively good,the contact angle was relatively large,the material was relatively hydrophobic,and the water absorption was relatively small.For silane coupling agent,it can significantly improve the mechanical properties of the material.When the content of silane was about 6%,the mechanical properties of the material were relatively good.At this time,the tensile strength was greatly improved,with the value of 19.68 MPa,while the bending strength was 52.3% higher than that without coupling agent,and the Rockwell hardness was relatively high,with the value of 138 hrb.For sodium hydroxide,when the concentration of sodium hydroxide was 4%,the mechanical properties of the material were better,and the contact angle was larger,reaching 102° and the water absorption was relatively small.