Waterborne Partially Corsslinked Polyurethane as Textile Auxiliaries
William Zhang
St George's School
Floor Location : S 132 N

Do you have a jacket that won’t become wet when it rains? When you accidently spill some water onto your tablecloth or sofa, do they form little droplets on top of the fabric? These water repellent fabrics are making our lives easier and better. Unfortunately, the convenience comes at a cost. Traditional waterproof agents on textiles are polymers containing fluorine. These fluorocarbon compounds are toxic; they also don’t decompose easily and accumulates in organisms. Therefore, scientists have been trying to develop waterproof agents without fluorine, but these products don’t perform as well as fluorocarbon compounds on many textiles’ surfaces.

Polyurethane surface coatings are used when surfaces require abrasion resistance and flexibility. In addition, it is fast curing, exhibit good adhesion to the substrate to which it is coated, and yield a chemically resistant coating. US patent 5354808, which was issued to 3M Corp. in 1994, described water-dispersed polyurethane compounds that can be used as surface coatings for vinyl floors. I thought to myself if polyurethane can be directly applied to floor surface, it probably can apply to fabrics too. I designed some polymers following the suit of the design in the patent with some alteration. After making the water-dispersed polyurethane, I tested its performance on fabrics. The fabric didn’t become fully waterproof, but it was stiffened. With further improvements, the waterborne polyurethane can become an alternative waterproof and stiffening agent. It shows a more eco-friendly and sustainable way of fabric treatment.