苎麻织物表面改性对其增强热固性聚乳酸复合材料力学及阻燃性能的影响

采用碱处理、硅烷偶联剂处理、碱+硅烷偶联剂复合处理、碱+阻燃剂+硅烷偶联剂复合处理对苎麻织物进行表面改性,采用模压工艺制备了苎麻织物增强热固性聚乳酸(PLA)复合材料。研究了4种表面改性方法对苎麻织物/PLA复合材料弯曲性能的影响,采用SEM研究了苎麻纤维与PLA基体之间的界面结合状况。结果表明:经过4种表面改性处理后苎麻织物/PLA复合材料的弯曲性能均有所提高,其中碱+硅烷偶联剂复合处理后提高幅度最大,苎麻织物/PLA复合材料的弯曲强度、模量分别提高了59.5%、51.9%。碱+阻燃剂+硅烷偶联剂复合处理后苎麻织物/PLA复合材料的弯曲强度、模量较未处理时分别提高了38.0%、66.8%;且苎麻织物/PLA复合材料60s点火时间的损毁长度为8.25cm,达到了美国DOT/FAA/AR-00/12要求的标准。SEM结果表明:改性处理后苎麻织物/PLA复合材料中纤维与树脂之间的界面结合更好。

Effect of surface modification on properties of mechanical and flame retardant of ramie fabrics reinforced thermosetting polylactic acid composites

The surface of ramie fabrics was modified by using four sorts of methods including alkali treatment, silane coupling agent treatment, alkali+silane coupling agent treatment, alkali+flame retardant+silane coupling agent treatment. Then ramie fabrics reinforced thermosetting polylactic acid (PLA) composites were prepared by means of compression molding technology. The effects of the four surface modification methods on flexural properties of ramie fabrics/PLA composites were studied. SEM was used to describe the interface bonding condition between ramie fiber and PLA matrix. The results reveal that after treating ramie fabrics using the four surface modification methods, the flexural properties of ramie fabrics/PLA composites all increase, especially, the increase of flexural strength and modulus is the most with alkali+silane coupling agent treatment, and increases 59.5%, 51.9%, respectively. Alkali+flame retardant+silane coupling agent treatment improves the flexural strength and modulus by 38.0%, 66.8%, and the burn length is 8.25 cm when the ignition time of ramie fabrics/PLA composites is 60 s, which reaches the demand of American standard DOT/FAA/AR-00/12. The results of SEM show that a better interface adhesion occurs between fiber and resin in ramie fabrics/PLA composites after modification treatment.