ABS新型无卤膨胀阻燃体系的研究

Effect of Novel Intumescent Retardant on Flame Retardancy of ABS

以聚磷酸铵(APP)为酸源,聚对苯二甲酰己二胺(PA6T)为炭源,探讨了不同比例的APP/PA6T复配对丙烯腈-苯乙烯-丁二烯共聚物(ABS)燃烧性能及其降解成炭行为的影响。结果表明,当APP含量为25%、PA6T含量为5%时,阻燃体系的极限氧指数达到29%,通过UL-94测试V-1级;再添加2%协效剂次磷酸铝,可通过V-0级。热失重分析表明,PA6T有较好的成炭作用,APP能极大改变PA6T的热分解行为,使ABS/APP/PA6T阻燃体系的高温残炭率大大提高。SEM形貌分析表明,阻燃体系燃烧表面形成了膨胀、均匀、致密的炭层结构。此外,通过对残炭进行红外分析,发现存在化学键P—O—C,进一步验证了该膨胀阻燃体系的协效成炭行为。

A novel intumescent flame retardant （IFR）, containing ammonium polyphosphate （APP） and poly （hexamethylene terephthalamide） （PA6T）, was prepared for acrylonitrile-butadienestyrene copolymer （ABS）. It was found that when the contents of APP and PA6T were 25 % and 5 %, respectively, the limiting oxygen index of ABS/IFR system reached 29%, but only UL-94 V1 rating was passed. Thus, Al（H2PO2）3 was incorporated into ABS/APP/PA6T system as a synergistic agent. It was found that 2% addition of Al（H2PO2）3 caused PA6T/APP/PA6T（70/ 23.3/4. 7） to pass V-0 rating of UI=94 test. Meanwhile, the TG curves indicated that PA6T was effective as a charring agent and there was a synergistic reaction between PA6T and APP, which promoted the char formation of ABS/IFR system. The residual char after the limiting oxygen index test was characterized using Fourier transform infrared spectra. It showed that P--O^C bond was formed in the residual char, indicating the cross linking reaction occurred. Furthermore, scanning electron microscopy revealed that both ABS/APP/PA6T （70/25/5） and PA6T/APP/PA6T/ AI（H2PO2）3 （70/23.3/4. 7/2） formed uniform and compact intumescent charred layers.