Mechanical properties
3.3.1. Effect of relative humidity
Mechanical properties of starch and starch/PLA foams
(after being conditioned in a specified relative humidity
atmosphere for 7 days at 25 8C) were measured and the
results are shown as a function of relative humidity in Fig. 4.
The values of both the tensile and flexural strength for all
of the foam specimens investigated were found to
increase initially with increasing relative humidity