Blend films of poly(acrylic acid-co-maleic acid) with poly(vinyl alcohol) (I):: Thermo-mechanical properties and gas permeability

Blends of poly(acrylic acid-co-maleic acid) (PAM) with poly(vinyl alcohol) (PVA) were obtained by solution blending. The blends were solvent-on to a film to examine thermo-mechanical properties and gas permeability. The transition temperatures (T-g and T-m) of the blends remained constant regardless of PAM contents. However, the values of enthalpy changes corresponding to melting transition (Delta H-m) and initial degradation temperature (T-D(i)) were decreased with increasing PAM content. The values of ultimate strength and initial modulus gave the maximum value at the 12 wt% PAM then decreased with further increase of PAM content up to 15 wt%. To measure the gas permeability of the PVA/PAM blend films, the PVA blend solutions were coated onto both biaxially oriented propylene (BOPP) and poly (ethylene terephthalate) (PET) films. The oxygen transmission rate (O-2 TR) permeability values monotonically decreased with increasing PAM content. However, moisture vapor transmission rate was not affected by PAM content.