Mechanical properties values from tensile tests of TPS-talc bio-
nanocomposites had the same order of magnitude than those re-
ported by Carvalho, Avérous, and Tadini (2011) for TPS films
containing native and organo-modified clays. However, those au-
thors observed a different effect of filler incorporation on TPS film
mechanical properties. They stressed that the addition of 3% w/w
montmorillonite to a matrix based on starch with 23% w/w glycerol,
reduced tensile strength and elongation at break around 40 and 60%,
respectively. In this sense, talc nanoparticles improved notably TPS
mechanical performance by increasing film stiffness and tensile
strength without affecting their ductility. Table 1 also presents yield
strain and resilience modulus, as well as, toughness values. Resil-
ienceisthe abilityofamaterialtoabsorbenergywhen itisdeformed
elastically upto yield strain,andreleasethatenergy uponunloading.
In this sense, resilience modulus is defined as the maximum energy
that can be absorbed per unit volume without creating a permanent
distortion. From tensile tests results, a significant (p < 0.05) incre-
ment in Urvalues of TPS films was observed for talc concentrations
higher than 3% w/w, while the same effect was detected from 1% w/
w talc addition in quasi-static assays. Particularly, incorporation of
5% w/w talc particles to starch based films caused an increment of
634 and 229% determined by tensile and quasi-static tests, respec-
tively. Resilience modulus and yield strain increment are indicative
of the relevance of adding talc nanoparticles to TPS materials in
order to reinforce the matrix improving their elastic response. On
the otherhand, toughness is defined as the material ability to absorb
energy up to fracture. TPS films toughness was raised with talc
concentration reaching an increment of 94 and 59% for 5% w/w talc
addition, determined by tensile and quasi-static tests. Talc contri-
bution to TPS films toughness could be associated to particle rein-
forcement of starch matrix as it was reflected in the mechanical
properties previously discussed