The blending of two or more polymers is becoming a
common method for developing new materials for demanding
applications such as impact resistant parts and packaging
films. Since the ultimate properties of blends can be
significantly affected by what polymers are present, as well
as by small changes in the blend composition, suppliers of
these materials are interested in rapid tests which provide
verification that the correct polymers and amount of each
polymer are present in the blend. Differential scanning
calorimetry (DSC) has proven to be an effective technique
for characterizing blends such as polyethylene/polypropylene
where the crystalline melting endotherms associated
with the polymer components are sufficiently separated to
allow quantitation. However, many blends do not exhibit
this convenient separation and thus are difficult to accurately
quantify by conventional DSC.