PPE Weathers Heat and Humidity Better than PA
Sabic has introduced Noryl GTX 9500 resin, an addition to its range of unfilled Noryl GTX resin grades that delivers dimensional stability under hot and humid conditions, addressing the challenge for highly demanding automotive applications. The material is a blend of polyamide (PA) and modified polyphenylene ether polymer (PPE) resins.
Sabic’s Noryl GTX 9500 resin reportedly retains a better balance of mechanical properties when exposed to heat and humidity typical of automotive under-hood environments than polyamide (PA) 66 and 6 resins. It also has comparable high flow and high-temperature performance, according to Sabic. The material’s dimensional stability and mechanical property retention under a range of temperatures and humidity — together with high flow performance — can open opportunities for thin-wall designs that reduce weight.
Target applications for Noryl GTX 9500 resins include vehicle junction boxes, connectors, and other applications requiring dimensional stability. These materials also demonstrate a potential for use as the base resin in carbon-fiber-reinforced thermoplastic composites used in structural and body components, and for applications in the industrial, aerospace, and marine markets.
“Our global development teams excel in formulating thermoplastics with targeted properties that resolve longstanding customer challenges, such as the propensity of nylon to soften under exposure to moisture,” said Darpan Parikh, Global Product Management Leader, Resins & Compounds.
“We designed Noryl GTX 9500 resin to give our customers innovative new material options for applications that must retain their shape and performance in hot, humid environments,” added Shinsuke Nakamoto, Senior Business Manager, Noryl Portfolio, Asia Pacific.
The tendency of PA resins to absorb moisture and water, which is exacerbated by elevated temperatures, may cause softening, loss of stiffness, and warpage. Noryl GTX 9500 resin offers significantly lower water and moisture uptake than PA, even under heat conditions up to 150°C. In fact, Sabic testing demonstrated that Noryl GTX 9500 resin absorbed 21% less moisture at equilibrium than PA 66, and 58% less than PA 6.
With moisture absorption at equilibrium, Sabic’s Noryl GTX 9500 material surpasses PA in dimensional stability. Noryl GTX 9500 resin exhibits a total dimensional change (flow direction and crossflow direction) of 0.29%, while PA 66 has a total change of 84% and PA 6 a total change 165% higher than Noryl GTX 9500 resin. This improved dimensional stability offers benefits for moisture-sensitive applications, including reducing warpage to minimize scrap rates and enabling designs with thinner walls to support lightweighting.
Noryl GTX 9500 resin also demonstrates exceptional retention of mechanical properties — flexural modulus, tensile modulus, and flexural strength — under wet conditions compared to PA 66 and PA 6. Furthermore, this material surpasses incumbent Noryl GTX grades based on PA in terms of water and moisture uptake, dimensional stability, and property retention.