High-barrier packaging is of interest to those
packaging products in the food, pharmaceutical, medical, chemical and cosmetics
industries. It is required to protect packaged products from the infiltration of
unwanted gases, water vapor and flavors. High-barrier films are usually achieved
by co-extrusion, lamination, coating and layering of polymer films. However,
problems such as de-lamination and migration can limit the effectiveness and/or
robustness of these barrier films, eventually compromising the barrier
characteristics of the packaging. Furthermore, presently available barrier films
have been found to be environmentally burdensome because they are not
biodegradable. In addition to these shortcomings, there is a growing trend in
the packaging industry towards utilizing sustainable materials to make films for
various applications. This trend is driven by social, political, economical and
environmental concerns motivating a desire to lessen dependency on
petroleum-derived products. Hence, technologies are sought that will lessen the
environmental burden and petroleum-based content of polymeric blends, while
enabling more robust barrier packaging.
Description
This invention provides a bio-based,
biodegradable-polymeric composition that can be used for high barrier packaging
applications. The composition consists of a stiff polymer and a flexible
polymer, compounded with clay. The stiff polymer is bio-based and is either
polylactic acid (PLA) or polyhydroxybutyrate (PHB). The flexible polymer is
poly-(butylene adipate-co-terephthalate) (PBAT), and the clay component is
montmorillonite clay with nano-sized particles that have been modified with
fatty acid quaternary ammonium cations to aid in dispersion. The mixture is
reactively blended and has low permeability to water vapor and oxygen as a
molded product or blown film. It also has a combination of strength, elongation,
and toughness that makes it useful for high barrier packaging applications. The
biodegradable blend can be extruded into a thin film that can be used for
packaging food and other perishable items.
Benefits
- Enables
improved barrier packaging with a biodegradable film: The bio-based blend
provided by this invention can be formed to make film for high barrier
applications and will not be environmentally burdensome.
- Reinforced
film has high performance characteristics: Polymer-clay nanocomposites
have good dimensional stability; resist permeation of oxygen, water vapor, and
carbon dioxide; have a higher heat distortion temperature; improved flame
retardancy; and improved thermo-mechanical properties compared to polymers
without reinforcements.
Application
The high-barrier film provided by this invention is
useful as a biodegradable alternative for packaging food and other perishable
items, and may be useful for packaging pharmaceuticals, cosmetics, medical
devices and sensitive electronics.
IP Protection
Status
1 U.S. patent issued:
7,619,025
