Low-Migration Macromolecular Benzophenones as UV Absorbers for Food Packaging Polymers

Extending the durability of polymer plastics and minimizingtoxicityconcerns to humans and the environment are among the essential goalstoward sustainability. Continuing our efforts in this area, we reportherein the design, optimized synthesis, and migration studies of macromolecularbenzophenones (MBPs) using three important building blocksincluding poly(ethylene-co-acrylic acid), pentaerythritol,and tris(2,3-epoxypropyl)isocyanurate for sustainable food packagingapplications. All MBPs are synthesized in gram scales,with the synthetic limitations being investigated. Interestingly,polymer-bound triphenyl phosphine is found to be an effective andrecyclable Lewis-based catalyst for an epoxy ring opening reactionto prepare an MBP in only one step starting from 2,4-dihydroxybenzophenone.The migration profiles of MBPs are much improved in comparisonwith that of the small molecule BP-1 (Uvinul 3008) andon par with the Food and Drug Administration-approved macromolecularcyanoacrylate Uvinul 3030 (UVN). They also show an excellentability to protect polystyrene from photodegradation and yellowingprocesses, suggesting that they may find a real-life application inthe plastic industry.