Study of PBAT/PLA bio based foams reinforced with chicken eggshell nano powder compatibilized with ionizing radiation

Abstract

Eggshell is a solid waste, with production of several tons per day and it is mostly sent to landfills at a high management cost. It is economically viable to transform eggshell waste to acquire new values, transforming it into a bioplastic: a biodegradable polymer made from bio mass. Chicken eggshell nano powder will be used for reinforcement of biodegradable polymers: PLA (poli lactic acid) and PBAT (butylene adipate co terephthalate), at 2.5, 5.0 and 10.0 %. Previous studies using PBAT/PLA, 50/50 blends containing 15% of chicken eggshell 125 μm improved mechanical behavior of net blends: values for both force and strain practically doubled, proving the effective reinforcement action of bio calcium carbonate. Biodegradable polymers as PLA (poli lactic acid) and PBAT (butylene adipate co terephthalate) are thermoplastics which can be processed using conventional polymer processing methods. PLA is high in strength and modulus (63 MPa and 3.4 GPa, respectively) but brittle (strain at break 3.8%) while PBAT is flexible and tough (strain at break ∼710%). In order to reduce interfacial tension exhibited by PLA/PBAT blend, compatibilization is fundamental: herein it was used as compatibilizing agent PLA previously e beam irradiated at 150 kGy: ionizing radiation induces compatibilization by free radicals, improving the dispersion and adhesion of blend phases, without the use of chemical additives and at room temperature. PBAT/PLA blends were prepared at the weight ratio of 82 / 18 together with compatibilizing agent: 5.0 % of PLA 150 kGy e beam radiated. Samples were first homogeneized in a co rotating twin screw extruder and further foamed in a mono screw extruder, by using CO2 as Physical Blowing Agent (PBA). Characterizations involved: DSC, TGA, FTIR, XRD, Tensile Strength and Elongation at Break.