Many industries that rely on polyurethanes, including the personal care and cosmetics industries, are looking to develop alternate products that are environmentally friendly and nontoxic. In styling products, waterborne polyurethanes (WBPU) have the potential to be this eco-solution, providing a product that exhibits strong, lasting results while maintaining a natural feel.

In their communication in Advanced Materials, Dr. Soo-Young Kang from Living Proof, Inc.; Prof. Robert Langer from the Massachusetts Institute of Technology; and co-workers describe the design and synthesis of over 300 waterborne polyurethanes and demonstrate their effectiveness for long-lasting, durable hair styling.

Prof. Robert Langer: “The Living Proof research team has spent over two years developing over 300 different WBPU materials, which, to our best knowledge, is the largest number of WBPUs ever reported in the literature. This large library of WBPUs, through systematic controlling of key parameters, allowed the team to establish a true structure–activity relationship.”

Dr. Soo-Young Kang: “The establishment of this large WBPU library enabled us to identify optimal WBPU mechanical properties and hydrophobicity.”

The addition of unsaturated linoleic acid to WBPU solutions also improved their sensory properties, giving the product a natural result.

Dr. Soo-Young Kang: “This is the first time that optimal WBPU properties have been identified for cosmetic application. Using hair styling as an example, we demonstrated that only the WBPUs with these optimal mechanical properties and hydrophobicity can achieve strong styling performance.”

Pre-curled tresses were styled using a representative WBPU solution and two different commercial polyurethanes. The WBPU solutions showed superior styling performance in comparison to the two commercial products.

Prof. Robert Langer: “This work not only provides new insight into WBPU design and synthesis, but also offers a new platform for developing WBPUs for other industrial applications.”

To find out more about these WBPUs for durable styling products, please visit the Advanced Materials homepage.