Macromolecular benzylidene malonates with low migration profiles for food-packaging applications

Benzylidene malonates constitute an important commercialized class of light stabilizers that are able to inhibit undesired photodegradation in polymers and plastics. However, the benzylidene malonate type of structures has yet to be FDA-approved for food-contact applications due to migration issues. Herein we report the design, synthesis and migration studies of three macromolecular benzylidene malonates (MBMs 1-3) by varying their structures, molecular weight and chemical composition. All MBMs were characterized with nuclear magnetic resonance spectroscopy, thermo-gravimetric analysis, photodegradation resistance property, resistance to yellowing upon UV exposure and migration studies using five different food simulants. Notably, the migration profiles of all MBMs are improved in comparison to the low molecular weight benzylidene malonate BM-4. The performance of MBM-3 synthesized by anchoring benzylidene malonate units to a poly(ethylene-co-acrylic acid) backbone against migration and photodegradation is the best amongst our three products and on par or better than the one of Uvinul (R) 3030 - an FDA-approved light stabilizer for food contact applications.