Typical diffusion behaviour in packaging polymers - application to functional barriers.

摘要: When plastics are collected for recycling, possibly contaminated articles might be recycled into food packaging, and thus the contaminants subsequently migrate food. Multilayer functional barriers may used to delay reduce such migration. The contribution of work reported here is establish reference values (at 40°C) diffusion coefficients activation energies predict barrier efficiency a broad range polymers (polyolefins, polystyrene, polyamide, PVC, PET, PVDC, [ethylene vinyl alcohol copolymer], polyacrylonitrile acetate copolymer]). Diffusion (D) (Ea) were measured compiled together with literature data. This allowed identification new trends log D=f(molecular weight) relationships. slopes function polymer temperature. apparent energy displayed two domains variation molecular weight (M). For low M (gases), there was little Ea. Focusing on larger molecules, high dependence Ea M. decreased T. These results suggest discontinuity between rubbery glassy polymers. © 2006 Taylor & Francis. Chemicals / CAS: ethylene copolymer, 24937-78-8; 25067-34-9; polyacrylonitrile, 25014-41-9, 63231-45-8; 63428-83-1; polyethylene terephthalate, 25038-59-9, 9003-68-3; 9003-53-6; polyvinylchloride, 9002-86-2; rubber, 9006-04-6; vinylidene chloride, 25323-30-2, 75-35-4; Acrylic Resins; ethylene-vinyl ethylenevinylacetate Nylons; PL 732, 83136-87-2; Plastics; 25014-41-9; Polyenes; Polyethylene Terephthalates; Polymers; Polystyrenes; Polyvinyl Chloride, Polyvinyls