temperature Switchable Membranes For Creating and Maintaining Beneficial Package Atmospheres for Fresh Produce

摘要

Microporous membranes, coated with side chain crystallizable (8CC) polymers, are currently used as part of a fresh produce bag to provide the permeability to oxygen and carbon dioxide that the produce needs to continue respiring and maintain quality. The membrane can be used to provide most or all of the requirements of produce, making it suitable for use with impermeable packaging materials or for packing very large quantities, e.g., 1000 lbs. of pro- duce. The membrane will also increase its permeability to oxygen and carbon di- oxide with temperature to supply some or all of the increased respiration needs of produce as the temperature increases. The switch temperature of the mem- brane can be tailored to occur at any temperature between 0 and 68°C. It poten- tially has applications in areas beyond fresh produce, where a specific gas con- centration is needed below one temperature, but is vented above that temperature.