含硫化合物阻燃聚碳酸酯及其阻燃机理

Polycarbonates Flame Retarded by Sulfur-containing Compounds and their Flame Retardant Mechanism

论述了含硫化合物(磺酸盐、磺酰胺盐)及其与聚硅氧烷等的复配物阻燃聚碳酸酯(PC)的特点、配方及性能,详细讨论了硫化合物阻燃PC的机理。为赋予PCUL94V-0或5V阻燃级,极限氧指数(LOI)达40%,所需硫化合物或复配物的添加量甚低,一般小于1%。而阻燃PC的其他性能几乎与未阻燃PC基材相仿。硫化合物在凝聚相中加速PC交联成炭,从而发挥阻燃作用,但对成炭率影响甚小,而气相阻燃作用则是次要的。硫化合物能使PC异构化及发生Fries重排而有助于交联成炭。

The characteristics, formula and properties of PC flame retarded by sulfur-containing compounds （sulfonates or sulfonamidates） and their mixtures with polysiloxane etc. were reviewed, and the flame retardant mechanism was discussed in detail. A small amount （usually less than 1%） of sulfur-containing compounds or their mixtures is needed to impart PC UL94 V-0 or 5V grade and LOI 40%. Other properties of the flame retardant PC are similar to those of pure PC. Sulfur-containing compounds acted mainly in the condensed phase by accelerating the cross linking and char formation of PC while with little increase of char yield. The contribution in the gas phase is negligible. Isomerization and Fries rearrangement of PC caused by sulfur- containing compounds are helpful to the cross linking and char formation.