Blends of thermoplastic starch and natural rubber were
obtained directly form the latex and granular cornstarch.
The dispersion of rubber in the thermoplastic starch
matrix was homogeneous thanks to the presence of the
aqueous medium, with rubber particles ranging in size
from 2 to 8 mm. The process employed in this
investigation called upon the use of both starch and
latex in their natural form, without any kind of
purification. Moreover, the presence of the non-rubber
constituents of the latex was responsible, not only for
insuring the latex stability, but also for improving the
compatibility between the thermoplastic starch and the
natural rubber phases. The addition of rubber was,
however, limited by phase separation the appearance of
which depended on the glycerol content. Finally, glycerol
seemed to contribute to both the platicisation of starch
and to the improvement of the starch–rubber interface.