Impact Modifiers Nylon

Dow has a broad range of nylon impact additives which include ionomers, ethylene copolymers and grafted polymers. From general-purpose toughness to intermediate and super-tough levels, Dow nylon impact modifiers meet the unique needs of nylon PA 6, PA 6,6 orglass-reinforced PA compounds.

Dow polymers for nylon impact modification include:

  • Fusabond® grafted polymers
  • Surlyn® ionomer resins

With its Fusabond® and other nylon impact resins, Dow offers low-modulus polyolefins with reactive groups providing anhydride and acid functionalities. The reactive groups enable chemical bonds, boosting adhesion of the toughener or impact modifier to the continuous phase of the compound.

Nylon impact strength measured by Notched Izod testing depends very much on test temperature. Thus a nylon modifier may provide super-toughness at room temperature, yet only achieve general-purpose toughness at -40°C test temperatures.

Fusabond® Grades Used for Nylon Impact Modification

Fusabond® N493 X X X Super toughening
Fusabond® N416   X X Super toughening; balance between toughness
Fusabond® N525 X X   Super toughening
Fusabond® A560 X   X Moderate toughening, enhanced gloss, mainly used in glass-reinforced systems
Graph 1: PA6 –Improved toughening performances of Fusabond® N493 resin

These graphs illustrate the broad range of performance level achieved based on different toughener requirements.

In applications such as sporting goods, using Fusabond® can increase low temperature nylon impact toughness, or deliver intermediate toughness at reduced cost (lower loadings). Improved flow for higher productivity can be achieved with Fusabond® N 598 in PA6. Fusabond® also can be a good choice for surface appearance (up to Class A) or nylon color compounding.

Graph 2: PA6,6 –Improved toughening performances of Fusabond® N493 resin

Dow™ Fusabond® nylon impact modifiers increase toughness by providing high polymer affinity to glass and mineral fillers. At concentration as low as 3.5% to 7%, for example, Fusabond® A560 can increase the Notched Izod impact strength of glass-reinforced (GR) nylon by up to 30% to 50%.

Two additional benefits of using Fusabond® compared to other nylon impact modifiers are:

  • Reduced compound melt viscosity, which can help with mold filling and surface appearance of glass-filled parts; and
  • Better mechanical property retention, sacrificing less of the compound’s needed tensile strength, modulus, or heat deformation temperature in order to meet needed nylon impact resistance.
Graph 3: PA 6,6 –Improved toughening performances of Fusabond® A560 resin

Ionomer Resin For Cost-Effective Single-Screw Nylon Impact Toughening
Dow™ Surlyn® ionomer resin also can be used to boost nylon impact resistance. Its polymer chemistry facilitates dispersion into nylon. This helps single screw extruders make toughened alloys that can meet food contact requirements, or make tough nylon molding compounds. Several ionomer grades for nylon impact modification are described further on the Surlyn® nylon toughener page on this site.