壳聚糖改性聚乳酸的阻燃性能分析

为解决聚乳酸(PLA)易燃、熔滴等问题,以绿色天然高聚物壳聚糖为原料,采用甲磺酸、五氧化二磷、三聚氰胺对其改性,得到了一种绿色环保型阻燃剂———MPCS,与三聚氰胺聚磷酸盐(MPP)复配,形成了膨胀型阻燃剂(IFR)。将IFR、α-磷酸锆(α-ZrP)和PLA用转矩流动仪熔融共混制备了阻燃聚乳酸复合材料。采用傅立叶红外光谱(FT-IR)、X射线粉末衍射(XRD)对MPCS的结构进行了表征;用垂直燃烧法(UL-94)、锥形量热测试(CCT)、热重分析(TGA)及电子扫描电镜(SEM)研究了聚乳酸复合材料的阻燃性能及其阻燃机理。结果表明,当添加3%α-ZrP和22%IFR时,PLA复合材料的阻燃性能达到UL-94V-0级且无熔融滴落;由于α-ZrP具有片层阻隔作用和催化成炭作用,α-ZrP能提高PLA/IFR复合材料的阻燃效果,降低热释放量和烟密度。

Analysis of Flame Retardancy of Modifiedchitosan for Polylactic Acid

A novel flame retardant named melamine chitosan Phosphate(MPCS),was prepared by using phosphorous pentoxide,melamine and chitosan,which were mixed with melamine polyphosphate(MPP)to form an intumescent flame retardant(IFR).IFR,α-ZrP used as a synergistic agent and polylactic acid(PLA)were used to prepare the flame retardant polylactic acid(PLA)composite by melt blending in a torque flow meter.The structure of MPCS was determined by Fourier transform infrared spectroscopy(FTIR)and X-ray powder diffraction(XRD).The flame retardancy of PLA composite was analyzed by means of vertical combustion,cone calorimetry test(CCT),thermogravimetric analysis(TGA)and electron scanning electron microscopy(SEM).The results indicated that the flame retardant properties of PLA reached to UL-94V-0 rating and without dripping when addition of 3%ofα-ZrP and 22%of IFR.α-ZrP could improve the flame retardant property,reduce the heat release and smoke density of PLA/IFR composite due to the lamellar barrier ofα-ZrP and the catalytic carbonization ofα-ZrP.