Antibacterial Properties of Biobased Polyester Composites Achieved through Modification with a Thermally Treated Waste Scallop Shell

Novel antibacterial properties of composites prepared from thermally treated waste white scallop shell powder (TWWSSP) and modified polylactide (MPLA) are reported. The waste shell (calcium carbonate, CaCO3) was calcined at 1000 °C to completely form calcium oxide (CaO) and calcium hydroxide (Ca(OH)2). The composition and structure of the calcined product were characterized using energy dispersive spectrometry, Fourier transform infrared spectroscopy, and X-ray diffraction. The TWWSSP was studied to determine its effectiveness as a bactericidal agent when incorporated into MPLA to form composites. Infrared, tensile, and morphological characterizations indicated an enhanced adhesion between the TWWSSP and the MPLA in the composites and an improved compatibility compared with the PLA/WWSSP composites. The MTT assay and cell adhesion tests on the composites revealed that the relative growth rate of Mus dunni fibroblast (MDFB) cells increased with an increasing TWWSSP content, which indicated that the composites were not cytotoxic. Moreover, TWWSSP containing CaO and Ca(OH)2 enhanced the antibacterial activity of the composites; MPLA composites that contained TWWSSP had a better antibacterial activity. The antibacterial and biodegradable properties of the MPLA/TWWSSP and PLA/WWSSP composites have a great potential for many applications, especially food packaging and biomedical materials