Low density polyethylene/poly(butylene adipate-co-terephthalate) films: Effect of a compatibilizer on morphology and properties

Low density polyethylene (LDPE)/poly(butylene)adipate-co-terephthalate (PBAT) blend films were fabricated using a cast film extruder with different content of PBAT (0,10, 20 and 30 wt%). Polyethylene-graft-maleic anhydride (PE-g-MA) was used as a compatibilizer for the LDPE/PBAT blends. Morphology, mechanical properties, thermal properties, water vapour and oxygen permeability properties of the LDPE/PBAT films with and without adding the compatibilizer were investigated. Scanning electron microscopic (SEM) results revealed that the LDPE/PBAT/PE-g-MA films showed better compatibility and homogeneity between LDPE matrix and PBAT phase. Young’s modulus and tensile strength of the LDPE/PBAT/PE-g-MA films were higher than those of the LDPE/PBAT films. The PBAT content and incorporating PE-g-MA did not affect on melting temperature (T m ) of the LDPE/PBAT blends. On the other hand, melting enthalpies (ΔH m ) of the polymer blends decrease as increase in PBAT concentration and at same content of the PBAT, the melting enthalpies (ΔH m ) of the LDPE/PBAT/PE-g-MA films were higher than those of LDPE/PBAT films. Water vapor transmission rate (WVTR) of the blend films increased but oxygen permeability (OP) decreased when the PBAT content increased. Compared with uncompatibilized LDPE/PBAT films at the same PBAT loading, the compatibilized LDPE/PBAT films provided a lower water vapor barrier whereas the LDPE/PBAT/PE-g-MA films showed a better oxygen barrier.