摘要
为改善聚乳酸的阻燃性能,利用植酸改性壳聚糖(PAMC)与三聚氰胺磷酸盐(MPP)复配得到一种新型膨胀型阻燃剂(IFR)体系,并将有机蒙脱土(OMMT)作为协效剂,通过熔融共混法制备阻燃聚乳酸(PLA)复合材料(PLA/PAMC/MPP/OMMT)。通过极限氧指数(LOI)、锥形燃烧量热(CONE)测试、垂直燃烧法(UL-94)和热重分析(TGA)测试分析复合材料的阻燃性能、燃烧性能和热稳定性能。采用扫描电镜(SEM)和X-射线光电子能谱(XPS)对复合材料的炭渣进行分析,研究了OMMT与PAMC/MPP在PLA复合材料中的阻燃协效作用。结果表明:与纯PLA相比,添加质量分数为25%的PAMC/MPP后,PLA2的LOI值、UL-94等级和800℃时的残炭量分别由21、NR和0.61%增至27.5、V-1级和17.28%,HRR曲线的峰值(PHRR)和总热释放量(THR)值分别由533.5 k W/m^2和81.7 MJ/m^2下降至270.2 k W/m^2和63.7 MJ/m^2。当添加质量分数为0.5%的OMMT后,PLA3的LOI值和残炭量继续增加至30.0和18.58%,PHRR和THR值进一步下降至251.6 k W/m^2和60.6 MJ/m^2,UL-94等级达到V-0级,且熔融滴落现象消失。OMMT与PAMC/MPP之间存在较好的协同效应,可有效改善PLA复合材料的阻燃性能,本研究结果可为制备绿色阻燃PLA复合材料提供理论依据。
In order to improve the flame retardancy of PLA, anovel intumescent flame retardant （IFR） polylactic acid（PLA） system （PLA/PAMC/MPP/OMMT） was prepared through direct melting-blending technique. The IFRsystem was composed of phytic acid modified chitosan （PAMC） and melamine phosphate （MPP） together with or-ganic montmorillonite （OMMT） as a synergistic agent. The flammability ,burning behavior and thermal stability of thecomposites were evaluated through the limiting oxygen index （LOI）, cone calorimeter test, vertical burning test （UL-94） and thermogravimetric analysis （TGA）. The char residues of the composites were characterized by scanning elec-tron microscopy （SEM） and X-ray photoelectron spectroscopy （XPS） to investigate the synergetic effect of OMMTand PAMC/MPP on the flame retardant properties of PLA composites. After incorporation of 25 wt% of PAMC/MPP, compared with PLA1, the LOI value, UL-94 grade and the residue rate at 800℃ of PLA2 were respectivelyimproved from 21.0, no class and 0. 61 wt% to 27.5, V-1 and 17.28 wt%, and the PHRR and THR values respec-tively decreased from 533.5 kW/m2 and 81.7 MJ/m2to 270. 2 kW/m2 and 63.7 MJ/m2. Compared with PLA2,when 0. 5 wt% of PAMC/MPP were replaced by OMMT, the LOI value and the residue rate at 800~（2 of PLA3 re-spectively increased to 30. 0 and 18.58%, and the PHRR and THR values decreased to 251.6 kW/m2and 60. 6 MJ/m2. The UL-94 test could pass V-0 rating and melt-dripping phenomenon disappeared. The above results indicated thatthe synergistic flameretardant effect between OMMT and PAMC/MPP showed a satisfied synergistic effect on theflame retardant properties of the PLA composites. The results from this study could provide theoretical basis for thepreparation of green flame retardant PLA composites.
出处
《林业工程学报》
北大核心
2017年第4期77-83,共7页
Journal of Forestry Engineering
基金
江苏省自然科学基金项目(BK2012821)
关键词
聚乳酸
植酸改性壳聚糖
有机蒙脱土
阻燃性能
协效
polylactic acid
phytic acid modified chitosan
organic montmorillonite
flame retardancy
synergistic effect
