Abstract
Nanocomposite materials based on polymers and various types of nanoparticles
or -fibres have gained much interest lately as packaging materials, coatings,
wound healing bandages, etc. Microfibrillated cellulose (MFC) with a thickness
of 1–50 nm and a length of several μm (regarded as a nanomaterial) has been
surface modified using its large number of hydroxyl groups. A wide variety of
new functionalities have been introduced, both reactive groups as epoxy,
amines, succinic and maleic acid for covalent introduction to matrix materials
and hydrophobic compounds such as octadecylamine and poly(styrene-comaleic
anhydride) for enhanced compatibility with the matrix. These modified
MFC may be added to various different commonly used polymers in food packaging,
e.g. PE, PP, PS, or paper, both to bulk materials and films to introduce
new and improved properties. The strength of base paper increased significantly
when coated with a layer of less than 10 % of MFC, whether pure or surface
modified, and the air permeability decreased dramatically.
Special focus will be given to antimicrobial MFC materials for use in food
packaging. The challenge with antimicrobial packaging materials is often possible
leakage to the food and/or fast wash-out with only temporary effect. Quaternary
C18 ammonium ions were covalently attached to MFC. These functional
groups disrupt the cell membrane of the bacterial cells through physical and
ionic phenomena and will kill bacteria attached to the packaging material. These
modified MFC are promising candidates as fillers for novel food packaging
nanocomposite materials, combining antimicrobial activity with increased
strength and decreased permeability due to fibre reinforcement.
or -fibres have gained much interest lately as packaging materials, coatings,
wound healing bandages, etc. Microfibrillated cellulose (MFC) with a thickness
of 1–50 nm and a length of several μm (regarded as a nanomaterial) has been
surface modified using its large number of hydroxyl groups. A wide variety of
new functionalities have been introduced, both reactive groups as epoxy,
amines, succinic and maleic acid for covalent introduction to matrix materials
and hydrophobic compounds such as octadecylamine and poly(styrene-comaleic
anhydride) for enhanced compatibility with the matrix. These modified
MFC may be added to various different commonly used polymers in food packaging,
e.g. PE, PP, PS, or paper, both to bulk materials and films to introduce
new and improved properties. The strength of base paper increased significantly
when coated with a layer of less than 10 % of MFC, whether pure or surface
modified, and the air permeability decreased dramatically.
Special focus will be given to antimicrobial MFC materials for use in food
packaging. The challenge with antimicrobial packaging materials is often possible
leakage to the food and/or fast wash-out with only temporary effect. Quaternary
C18 ammonium ions were covalently attached to MFC. These functional
groups disrupt the cell membrane of the bacterial cells through physical and
ionic phenomena and will kill bacteria attached to the packaging material. These
modified MFC are promising candidates as fillers for novel food packaging
nanocomposite materials, combining antimicrobial activity with increased
strength and decreased permeability due to fibre reinforcement.
