MSU Technologies

Water Dispersible Poly(dimethylsiloxane) Coatings for PFAS Replacement

Executive Summary

Polyethylene-, polyvinylidene chloride-, and per- and polyfluoroalkyl substances (PFAS) -coated paper is used in applications requiring barrier properties such as grease and water resistance. However, the use of these chemicals present environmental challenges and make the coated paper difficult to recycle or compost. Researchers at Michigan State University have recently developed a new coating for paper substrates that has excellent barrier and mechanical properties and PFAS free. The coating can be applied as a waterborne solution and the coated board shows promise for being fully recyclable at end of life.

Description of the Technology

The technology is based on emulsifiable poly(dimethylsiloxane) / starch coating. Tests have been done on Kraft paper applying the coating at approximately 50 g/m². Cobb60 down to 2.7 g/m², WVTR of 250 g/m²/day (75% reduction from the uncoated paper), kit of 12/12 for grease barrier. Various mechanical tests were performed on the coated paper including tensile, bending stiffness, ring crush test, internal tearing resistance showing the coated paper retained up to 90% of the mechanical properties of the uncoated version. The coated paper was then dissolved in warm water, filtered, the fibers washed with sodium bicarbonate, then used to make new paper, suggesting the coated paper could be recycled.

Benefits