Rubber Soles
Rubber has long been one of the most popular sole materials due to its excellent traction on both wet and dry surfaces. There are a few different types of rubber soles:

Natural Rubber - Derived from latex, natural rubber soles offer good durability and flexibility. They are affordable but may wear down more quickly than other materials.

Synthetic Rubber - Synthetic rubbers like ethylene-vinyl acetate (EVA) and thermoplastic polyurethane (TPU) are man-made versions that provide comparable traction to natural rubber at a lower cost. Synthetic rubbers usually stand up to wear and tear better than natural versions.

Rubber Outsoles - These Footwear Sole Materials involve bonding a rubber outsole onto a removable insole for reparability. This extends the lifespan of the shoe by allowing just the outsole to be replaced when worn down rather than replacing the entire shoe.

Rubber soles generally suit active and athletic shoes due to their slip-resistant traction. However, they may not provide as much cushioning as other materials.

Polyurethane Soles
Polyurethane, commonly called poly, is a durable synthetic material frequently used in shoe soles for its flexibility, lightweight properties and shock absorption qualities. There are two main types:

Foam Polyurethane - This microcellular foam polyurethane cushions each step for comfort. It tends to compress over time but recovers well. Good for casual and athletic footwear.

Thermoplastic Polyurethane - Known for its resilient rebound, TPU absorbs impact without breaking down. It works well in running and specialty shoes aimed at high-mileage wearers.

Polyurethane soles cushion the foot without adding excess weight to the shoe. Along with rubber, poly is ubiquitous in modern athletic footwear for its flexibility and shock-dampening properties.

Get More Insights on Footwear Sole Material