The biodegradation of two-component blends containing synthetic and natural
polymers was studied. Polyethylene, polypropylene and modified polyester w
ere used as synthetic components. Three materials of natural origin, i.e. p
owdered cellulose, sodium alginate and chitosan in lyophilized form, were u
sed as Filers. The samples were prepared in the form of films of different
thicknesses and contained various amounts of natural components. In general
the content of synthetic components ranged from 50 to 75wt%, natural polym
ers 5-21wt% and other additives 11-38wt%.
The biodegradation tests were carried out in soil and water. The effect of
microorganisms' action on the samples was estimated by the loss of mass, wa
ter sorption capacity and electron microscope studies. In some experiments
the mass lass exceeds the sum of masses of all introduced natural component
s. It means that some art of synthetic polymer is also damaged during biode
gradation.
Generally the results obtained lead to the conclusion that biodegradability
of two-component polymer films depends considerably on the dimensions of t
he natural component particles and their distribution in the film. Films co
ntaining large and weakly dispersed particles prove to be more sensitive to
biodegradation. Accessibility of natural component particles for the bath
containing microorganisms plays an important role in the biodegradation cou
rse. Films filled with cellulose are better degradable in soil while the fi
lms containing sodium alginate biodegrade in aqueous medium more easily. Co
pyright (C) 1999 John Wiley & Sons, Ltd.