Synergistic modification of long-chain polyamides with brominated polystyrene/Sb 2 O 3 for high-performance flame-retardant PA66 composites
Yike Zhang, Wenxi Cheng, Wei Miao, Weiqiang Song, Shaoshuai Wang, Bo Cheng, Shunli An, Hongsen Wang, Tao Wang, Xuanhuai WangAbstract
In this study, ternary blends of polyamide 66/polyamide 610/polyamide 12 (PA66/PA610/PA12) were firstly prepared, and exhibited the best mechanical performance when the mass ratio of PA610 to PA12 was 2:3 and their total content was 20 wt%. On this basis, the ternary blend was mixed with glass fiber (GF), brominated polystyrene/antimony trioxide (BS) to prepare a PA66 composite (PA66/610/12/BS/GF), and the samples without long chain polyamides and flame retardants (PA66/BS/GF and PA66/610/12/GF) were also prepared for comparison. DSC and XRD analyses showed that PA610 was immiscible with PA66 after short-time blending. Besides, long-chain polyamides (PA610 and PA12) and flame retardants, especially Sb 2 O 3 , increased the crystallinity ( X c ) of PA66 in the composites, leading to the highest X c of PA66 in PA66/610/12/BS/GF. SEM images revealed that BPS was dispersed in the polyamide matrix at a microscale size. Mechanical tests revealed that long-chain polyamides and flame retardants exhibited a synergistic effect, which could simultaneously enhance the strength and toughness of PA66/GF, and promote its charring reaction and char residue yield. In addition, all the composites containing flame retardants showed excellent flame retardancy, reaching the UL-94 V-0 rating. Therefore, PA66/610/12/BS/GF is a composite with UL-94 V-0 flame retardancy, high strength, high toughness and good thermal stability, and can be used for components requiring high comprehensive performance in the electrical and electronic, automotive and home appliance fields.