Abstract:

Toughened polyphenylene ether/polyamide 66 （PPO/PA66） blends were prepared through twin⁃screw extrusion and injection molding using maleic anhydride⁃grafted styrene⁃ethylene⁃butene⁃styrene copolymer （SEBS⁃g⁃MAH） as an impact modifier. Their water absorption， mechanical properties， melt flow performance were investigated and their crystallization behavior and fractured morphology were studied by differential scanning calorimetry and scanning electron microscopy. The results indicated the toughness and tensile strength of PPO/PA66 blends decreased significantly in the presence of PPO due to poor interfacial adhesion between PA66 and PPO. Owing to the energy absorption caused by SEBS⁃g⁃MAH as well as an improvement in the compatibility between PA66 and PPO， the addition of 10 phr SEBS⁃g⁃MAH into the PPO/PA66 （30/70） blend resulted in an increase in the tensile strength， elongation at break and impact strength by 23.95 %、81.58 % and 157.39 %， respectively. The PPO/PA66 （30/70） blend obtained better comprehensive properties with the addition of 10phr SEBS⁃g⁃MAH， and it achieved relative maximum toughness at the SEBS⁃g⁃MAH loading of 18phr. The PPO/PA66 （30/70） containing 10phr SEBS⁃g⁃MAH present a water absorption of 0.61 %. This result decreased by 55.88 % Compared to the water absorption （1.36 %） of pure PA66. PPO enhanced the crystal formation of PA66 in the bends， whereas SEBS⁃g⁃MAH inhibited its crystal formation of PA66. Both PPO and SEBS⁃g⁃MAH improved the melt processability of PA66.

Key words: polyphenylene ether, polyamide 66, maleic anhydride grafted styrene?ethylene?butene?styrene copolymer, mechanical property, water absorption, crystallization property