海泡石与APP对PVC/竹粉复合材料的阻燃抑烟机理

将海泡石(SEP)和聚磷酸铵(APP)同时加到聚氯乙烯(PVC)/竹粉复合材料中,考察SEP和APP对复合材料的协效阻燃抑烟作用及力学性能的影响。结果表明,在锥形量热实验中,热释放速率峰值相对减少42.8%,平均热释放速率和总热释放量相对减少29.5%和25.7%,总烟释放量相对降低了12.2%,一氧化碳平均产率相对降低了42.0%;扫描电子显微镜分析发现,APP具有催化成炭并形成膨胀泡沫炭层的作用,而SEP具有吸附聚集诱导成炭的作用;APP的阻燃机理主要属于气相阻燃机理,SEP的阻燃机理主要属于凝聚相阻燃机理;弯曲性能测试结果表明,SEP与APP对PVC/竹粉复合材料具有协同颗粒增强作用;拉伸性能测试结果表明,SEP对PVC/竹粉复合材料的塑性变形能力的损害比APP小。因此,SEP与APP联用能够对PVC/竹粉复合材料进行有效的阻燃抑烟,同时也能增强复合材料的力学性能。

Synergistic Flame Retardant Smoke Suppression Mechanism of Sepiolite and APP on PVC/Bamboo Powder Composites

The effects of sepiolite (SEP) and ammonium polyphosphate (APP) on synergistic effects of flame retardant and smoke suppression and mechanical properties of polyvinyl chloride (PVC)/ bamboo powder composites were investigated by add-ing SEP and APP. The results of the cone calorimeter experiment show that the peak heat release rate decreases by 42.8% relatively, the average heat release rate by 29.5% relatively and total heat release by 25.7% relatively,compared by a relative decrease of 12.2% in total smoke production and of 42.0% in the average yield of carbon monoxide. SEM analysis demonstrates that APP promotes catalytic charring and the formation of expanded carbon foam layer,and that SEP has a capability of adsorption and aggregation induced carbon. The flame retardant mechanism of APP is mainly gas phase flame retardant, SEP flame retardant mechanism mainly belong to condensed phase flame retardant. Bending test indicates that SEP and APP have synergetic particle reinforcing effect on the composites while tensile tests implies that SEP can cause less damage to the plastic deformation ability of the composites than APP. Therefore,SEP and APP can be used together for effective flame retardant and smoke suppression,and to improve the mechanical properties of the composites.