A chain extender is one of those additives you don’t think about until you need it. Polymers like PET or PBT can degrade during processing or recycling, losing viscosity and strength. Adding a chain extender essentially “rebuilds” the polymer chains, restoring melt strength, tensile properties, and overall durability. In real-world production, this allows recycled plastics to perform almost like virgin material. Engineers often tweak the amount depending on how much flow adjustment or mechanical improvement they need, especially for films, fibers, or molded parts. It’s not just about fixing degradation — it’s about giving the material a second life while keeping quality high.

Reactive Chain Extender for Polymer Molecular Weight Restoration

Sushil Brainfoster