聚偏氟乙烯/聚甲基丙烯酸甲酯交替多层材料的热稳定性

利用微层共挤出技术制得不同层数(2,16,64层)的聚偏氟乙烯(PVDF)/聚甲基丙烯酸甲酯(PMMA)交替多层材料,通过偏光显微镜、垂直燃烧测试、热失重分析、红外光谱分析、微型量热测试研究了层数的变化对体系热分解和热释放行为的影响。结果表明,PVDF层与PMMA层沿层状样品的厚度方向交替排列,层结构明显,层界面清晰,随着层数的增加,层界面数增加,材料的垂直燃烧行为几乎不变,但表现出更高的热稳定性;高层数样品中热稳定性优异的PVDF层对易热解的PMMA层保护作用增强,且在热释放过程中,更多的层界面为PVDF炭层的形成提供了更丰富的空间,使材料的热释放速率减小,总热释放降低。

Thermal Stability of Poly(vinylidene fluoride)/Poly(methyl methacrylate) Alternating Multilayered Materials

Poly (vinylidene fluoride) (PVDF)/poly (methyl methacrylate) (PMMA) alternating multilayered materials with different layer numbers (2,16 and 64) were fabricated through layer-multiplying coextrusion technology.The influence of layer numbers on the thermal decomposition and heat release behaviors of multilayered specimens was investigated through polarized light micrographs,vertical burning test,thermal gravity analysis,infrared analysis and micro calorimeter test.The results show that PVDF and PMMA layers are distributed alternatively along the thickness direction of the multilayered specimen.With increasing the layer numbers,the vertical burning behavior is nearly unchanged,but the thermal stability tends to be improved.It is considered that the enriched interfaces make more PVDF layers act as barriers to insulate heat transfer,so that the thermal decomposition of PMMA layers is significandy inhibited.