Structure of PBAT/PPC blends prepared by in-situ reactive compatibilization and properties of their blowing films

• PBAT/PPC biodegradable films were prepared by reactive extrusion and blow molding. • Rheological behaviour, phase morphology and crystallization properties of PBAT/PPC blends were researched. • The relationship between structure-morphology of blends and film processing and performance was revealed. • Addition of EMA-GMA enhanced mechanical, gas barrier and UV resistance properties of the films. Biodegradable films of poly(butylene adipate-co-terephthalate) (PBAT) and poly(propylene carbonate) (PPC) blends are prepared by reactive extrusion and blowing film. The effects of compatibilizer, ethylene-methyl acrylate-glycidyl methacrylate(EMA-GMA) on rheological, phase morphology and crystallization properties are investigated. It is shown from the rheological behavior of PPC/PBAT blends that the addition of EMA-GMA in the compounding of PPC and PBAT is beneficial to the stability of blown film processing. With increasing the content of compatibilizer (EMA-GMA) in PBAT/PPC (70/30), the radius of dispersed phase increases and some droplets (PPC phase) begin to coalesce. This coalescing of PPC droplets tend to form a partial co-continuous structure. The crystallization temperature of blends is also improved with the addition of EMA-GMA. When the melt strength and crystallization temperature is increased, the processing stability and quality of the blowing film is improved. Then a more uniform and smoother surface of films is obtained. Moreover, the mechanical, oxygen barrier and UV light shielding properties are improved with the addition of EMA-GMA, which will greatly broaden the application of biodegradable PBAT/PPC films in the field of photosensitive products packaging materials.