混合方式对增容尼龙-6/聚苯醚体系的影响

研究了三种混合方式对于Nylon 6 PPO TPEg共混体系的影响 .混合是在双螺杆挤出机上进行的 .即(A)尼龙 6、聚苯醚和TPEg的混合物直接进行熔融挤出 ;(B)尼龙 6与TPEg的混合物预挤出 ,然后与聚苯醚熔融挤出 ;(C)聚苯醚和TPEg的混合物预挤出 ,然后与尼龙 6熔融挤出 .实验结果表明 ,混合方式不仅会影响共混物的形貌结构 ,而且会影响复合材料的最终性能 ,如力学性能、热性能和尺寸稳定性 .采用混合方式C所得的尼龙 6 聚苯醚复合材料的抗冲击强度高于用混合方式A和B所制备的复合材料 .这是因为聚苯醚和TPEg预共混时 ,聚苯醚上的OH基团和TPEg上的一部分马来酸酐发生化学反应 .然后预混物和尼龙 6熔融挤出时 ,剩下的马来酸酐再与尼龙分子上的NH2 基团反应 .这样就会形成一个好的界面层 ,它使复合材料的抗冲击强度大幅度提高 ,材料达到了超高韧性

THE EFFECT OF MIXING PROCEDURES ON COMPATIBILIZED NYLON-6/PPO BLENDS

The effect of three mixing procedures on compatibilized nylon 6/PPO blends was investigated. A twin screw extruder was used in the experiment. (A) The mixture of nylon 6, PPO and TPEg was extruded; (B) the preblends of nylon 6 and TPEg through the extruder was co extruded with PPO; (C) the preblends of PPO and TPEg through the extruder was co extruded with nylon 6. The experimental results showed that the rational adaptation of processing method greatly affected the phase structure of the blend, and consequently affected the final properties of materials, such as mechanical properties, thermal properties and dimensional stability. The impact strength of the compatibilized nylon 6/PPO blends prepared via mixing procedure (C) is much higher than that of the compatibilized nylon 6/PPO blends prepared via mixing procedure (A)and (B).The reason is that the reactivity of —OH groups on PPO molecules is much lower than that of —NH 2 groups on nylon molecules. In mixing procedure (C), PPO was first preblended with TPEg which allowed the —OH group to react with part of the maleic anhydride groups, then in the following co extrusion with nylon 6 the un reacted maleic anhydride groups further reacted with —NH 2 groups on nylon molecules. With the two steps a good interface is formed and greatly improves the impact strength of the blends, and the material has the property of super toughness.