Polyolefin in Packaging and Food Industry

Biobased Polyester‐Amide/Cellulose Nanocrystal Nanocomposites for Food Packaging

“…The O 2 TR value of PEA75CNC5 is 2.06 × 10 4 cm 3 m –2 d –1 , which is in the same range as polyolefins (2.0 × 10 5 – 5.0 × 10 4 cm 3 m –2 d –1 ) used in current packaging applications. [ 3,14 ]…”

“…Before the advent of commodity polymers, the packaging of food products was dominated by metal and glass, because these materials are impermeable to gas molecules and thus provide excellent protection. However, the low specific weight, processability, and low cost have made polymers the selection of choice for food packaging, [ 1–3 ] so that the packaging industry now accounts for more than 40% of all plastics consumed. [ 4 ] The shift to polymeric packaging materials has contributed substantially to environmental pollution, because most of the materials employed in packaging are based on petrochemical sources, inefficiently recycled, and not biodegradable.…”

“…[ 4 ] The shift to polymeric packaging materials has contributed substantially to environmental pollution, because most of the materials employed in packaging are based on petrochemical sources, inefficiently recycled, and not biodegradable. [ 1–3,5 ] Mainly driven by sustainability considerations, there is, however, growing interest to replace traditional polymers such as widely used polyethylene and polypropylene by biobased and ideally also biodegradable packaging materials. Nevertheless, it proved difficult to develop alternative materials that match the mechanical and gas barrier properties needed for food packaging based on biobased polymers such as poly(lactic acid) and poly(hydroxybutyrate).…”

“…For example, 67% of the world's usage of low density polyethylene (LDPE) arises from film and sheets for food packaging. [ 3 ] To capture a large market, a biobased replacement material should therefore ideally exhibit mechanical and thermal properties that are in the same range as those of polyolefins. Depending on the density, typical polyethylenes used in packaging melt at temperatures between ca.…”

“…100 and 130 °C, exhibit plastic deformation behavior, and have a tensile strength of between 8 and 32 MPa. [ 3,12,13 ] Low‐density and high‐density polyethylene (LDPE and HPDE) have relatively high oxygen transmission rates (O 2 TR) of between 5.0 × 10 4 and 2.0 × 10 5 cm 3 m –2 d –1 , [ 5,12,14 ] which can be reduced by laminating these polymers with poly(ethylene‐ co ‐vinylalcohol) (pEVOH), which offers a low oxygen transfer rate (O 2 TR) of 0.1 to 1 cm 3 m –2 d –1 , but suffers from a high water vapor transfer rate (WVTR) value of 30000 cm 3 m –2 d –1 . [ 5,12,14 ] Such multilayer films offer a very attractive combination of barrier properties, mechanical characteristics and cost, but they cannot be recycled efficiently as the two components are difficult to separate and neither of them is biodegradable.…”