【作者】 徐亮；

【导师】 王旭；

【作者基本信息】 浙江工业大学 ， 材料学， 2010， 硕士

【摘要】 阻燃抗静电尼龙6（PA6）复合材料由于综合性能优越倍受关注。本论文采用PA6为基体，乙烯-醋酸乙烯酯共聚物（EVA）为弹性体，炭黑（CB）为导电填料，膦酸盐为阻燃剂制备阻燃抗静电PA6复合材料。研究了阻燃剂、弹性体、CB等对阻燃抗静电PA6的阻燃性能、抗静电性能、力学性能的影响，并利用SEM进一步观察分析了弹性体、CB等分散相的形态以及CB在体系中的选择性分布，为制备高性能的阻燃抗静电PA6复合材料提供指导。取得的主要研究结论有：1、通过压制成型制备的PA6/EVA/CB复合材料比通过注塑成型制备的PA6/EVA/CB复合材料具有较小的体积电阻率。一方面压制成型制备的复合体系由于具有较高的结晶度更有利于CB在复合体系的非晶区富集，另一方面由于压制成型制备的复合体系具有较低的剪切速率能更完整的保持复合体系的导电网络结构。2、在PA6、EVA、CB直接混合，EVA与CB先混合再与PA6混合，PA6与CB先混合再与EVA混合等三种混合方式下制得的PA6/EVA/CB复合材料中，采用PA6、EVA、CB直接混合制备的复合材料的体积电阻率与它们在一起总的混合时间有关，其它混合方式制备的复合材料的体积电阻率与它们在一起总的混合时间无关，直接混合制备的复合体系中，随混合时间的增加CB间的距离减小，体系的体积电阻率变小。3、阻燃剂三聚氰胺氰尿酸盐（MCA）对纯PA6具有明显的阻燃性能，其含量为8 wt%时，就能使PA6的阻燃性能达到FV-0级，但由于CB粒子的存在产生了类似“烛芯效应”导致其在阻燃抗静电PA6体系中阻燃性能失效；阻燃剂磷酸酯盐（PND）对阻燃抗静电PA6复合体系具有较强的阻燃作用，其阻燃机理主要是气相阻燃，当其在体系中的含量达到17.1 wt%时，复合体系的阻燃性能达到FV-0级；阻燃剂有机膦酸盐（PBA）对阻燃抗静电PA6具有较强的阻燃效果，其阻燃的主要作用机理是凝聚相阻燃，当其在体系中的含量为10.6wt%时，复合体系的阻燃性能就达到了FV-0级。4、凹凸棒能在阻燃过程中起到促进炭化层形成，能提高阻燃抗静电PA6复合体系的阻燃性能。由于PND是以气相阻燃为主的，凹凸棒的加入能对PA6/EVA/CB/PND复合体系起到促进凝聚相成炭的作用，因而有利于体系阻燃性能的提高；由于PBA本身以凝聚相阻燃为主，在少量凹凸棒存在下，对PA6/EVA/CB/PBA复合体系的阻燃性能没有大的提高，但随着凹凸棒含量的提高，体系的阻燃性能提高较明显。5、在阻燃抗静电PA6复合体系中，阻燃剂的加入没有破坏复合体系导电网络结构，故对复合体系抗静电性能基本没有影响；而CB的加入加剧了体系的无焰燃烧，故使复合体系的阻燃变得困难。更多还原

【Abstract】 Flame retarded and antistatic polyamide-6(PA6) (FRAPA6) composites have been paied much attention recently because of their excellent comprehensive properties. In this paper, FRAPA6 composites containing PA6, carbon black (CB), elastomer, and halogen-free flame retardant have been prepared by melt-mixing technology. The effect of CB, elastomer and flame retardant on volume resistivity, flame retardancy and mechanical properties of FRAPA6 composites was investigated. The morphology of dispersed phase and selective distribution of the CB particles was investigated by scanning electron microscopy (SEM). The conclusions were listed as follows:1. The plates of PA6/EVA/CB composites prepared via compression molding showed much better conductivity than the ones prepared via injection molding. On one hand, the samples prepared by compression molding had higher crystallinity, so CB particles tend to concentrate in the amorphous region of the composite system; on the other hand, the composites tend to keep continuous network due to the lower shear rate. 2. The distribution of CB particles significantly affected the electrical conductivity of the PA6/EVA/CB composites. Among three kinds of PA6/EVA/CB composites, including ones prepared by directly mixing, EVA and CB were mixed prior to melt-compounding with PA6 and PA6 and CB were mixed prior to melt-compounding with EVA, the mixing time only significantly influenced the electrical conductivity of composites prepared by directly mixing. Good conductivity of the composites could be realized because the distance between CB particles became closer with the increasing of mixing time.3. Three kinds of flame retardant including melamine cyanurate (MCA), phosphoric acid (PBA) and phosphatic ester (PND) were employed to study the influence on the flame retardancy of the FRAPA6 composites. The results showed that the vertical combustion grade of PA6 composites came up to FV-0 when the content of MCA was 8 wt%. When MCA and CB particles were used simultaneously, the flame retardancy of the composites was weakened dramatically. MCA become invalid, but the composites with PND could provide distinctive flame retardancy. It was showed that the vertical combustion grade of FRAPA6 composites came up to FV-0 when the content of PND was 17.1 wt%, and the grade came up to FV-0 when the content of PBA was 10.6 wt%.4. Attapulgite could improve the flame retardancy of FRAPA6 composites because of the enhancement of the char layer while burning. The flame retardant mechanism of PND used for FRAPA6 composites was the gas phase and the PBA played flame retarding role in condensed phase. When PND and attapulgite were used simultaneously, the flame retardancy of FRAPA6 composites was improved obviously. The flame retardancy of FRAPA6 composites did not improve when PBA and attapulgite were used simultaneously. Attapulgite had better synergistic effect to PND than PBA.5. Flame retardant did not destroy the continuous conductive network of the FRAPA6 composites. The CB particles had negative effect on the flame retardancy of FRAPA6 composites, because the composites exhibited“candlewick effect”with the addition of CB particles.更多还原