阻燃聚甲醛的研究

通过阻燃剂的筛选实验，正交实验和配方实验研制了阻燃聚甲醛（POM），并研究了阻燃POM的成型加工工艺。结果表明，最适于POM的阻燃剂为三聚氰胺，聚磷酸铵（APP）和季戊四醇双磷酸酯三聚氰铵盐（MPP）；将这三种阻燃剂复配使用，其效果比单独使用好，具有协同作用，在100份POM中加入40份APP和MPP的混合物及20份三聚氰胺，可使阻燃POM的氧指数达到49％；在100份POM中加入30份APP和MPP的混合物，20份三聚氰胺及10份吸醛剂A，可使阻燃POM的氧指数达到50％，垂直燃烧达FV－0级，两者的力学性能下降率小于50％＜阻燃POM挤出造粒时宜采用渐变式螺杆挤出机；注塑时宜采用螺杆式注塑机，挤出和注射成型的工艺条件与普通POM相同。

STUDY ON THE FLAME-RETARDANT POLYOXYMETHYLENE

Flame retardant polyoxymethylene (POM) was developed by means of screening, orthogonal and compounding experiments of the flame retardants, and its molding processing technology was also studied. The results showed that the flame retardants being most suitable for POM were melamine, APP and MPP. The effect of composite uses of the above flame retardants was better than that of single one, being of synergism for each other. When 40 parts of the mixture of APP and MPP, 20 parts of melamine were added to 100 parts of POM, the oxygen index of the flame-retardant POM would come up to 49% ; and when 30 parts of the mixture of APP and MPP, 20 parts of melamine and 10 parts of aldehyde absorbent A were added to 100 parts of POM, the oxygen index of the flame retardant POM would come up to 50% , with vertical burning being FV-0 grade. The drop rate of the mechanical properties of the a-bove modified POM was lower than 50% . When the flame-retardant POM was extruded, the gradational screw extruder was appropriately used; when the flame-retardant POM was injected, the screw injection machine was appropriately used. The extrusion and injection conditions of the flame-retardant POM were the same as common POM.