Effect of molding on the structure and properties of poly(butylene adipate-co-terephthalate)/poly(propylene carbonate)/organically modified montmorillonite nanocomposites

As an environmentally friendly biodegradable material, poly(butylene adipate-co-terephthalate) (PBAT) has been commercialized as a shopping bag, but its high gas permeability weaken its practicability in mulch, cling film and other fields. Two kinds of barrier materials, poly(propylene carbonate) (PPC) and organically modified montmorillonite (OMt), are used to prepare PBAT/PPC/OMt composites, and the mechanical properties are improved by chain extender (Joncryl (R) ADR 4468). The dispersion and arrangement of nanomaterials in blends are studied with different molding methods and their effects on the gas barrier and mechanical properties are studied as well. Dissipative particle dynamics are used to simulate the rate at which O2 molecules pass through the modified PBAT films. The results show that 1 wt% of chain extender can increase the tensile stress and tear strength by about 10% and 15%, respectively. The OMt is preferentially distributed in the PBAT matrix and has a more uniform degree of orientation in the blown film, which is beneficial to the improvement of gas barrier properties. Eventually, the mechanical properties and gas permeability of PBAT films can be regulated through the adjustment of processing methods and the synergistic effect of PPC and OMt, providing a new way for high-performance packaging or agricultural mulching film materials.