​Crystallization Behavior and Film Properties of Nylon 66-Rich Nylon 66/6 Copolymers

​Crystallization Behavior and Film Properties of Nylon 66-Rich Nylon 66/6 Copolymers

Doug Hoffman
Ascend Performance Materials

Polyamide6,6 (PA66) is a semi-crystalline thermoplastic that has many useful functions such as high temperature resistance (melting point = 260 C), strength, toughness, barrier, and chemical resistance. In injection molding processes its fast crystallization rate is often desired for fast cycle times but this property can be a limitation in film processes. For example in the case of blown film extrusion, PA66 has processing limitations often resulting in poor haze and gloss as well as secondary operation such thermoforming. The incorporation of monomers that do not co-crystallize with PA66 can reduce the crystallization rate up to 50 times while still producing PA66 rich copolyamides that are readily processable and have high melting points (> 215 C). These PA66 rich copolyamides compared to PA6 type polyamides possess enhanced mechanical film properties such as puncture resistance while improving film aesthetics (i.e., higher gloss and clarity) and film stretching (i.e., ease of stretching in biaxial stretching processes).