The preparation and properties of biodegradable polyesteramide composites reinforced with nano-CaCO3 and nano-SiO2

Composites were fabricated utilizing melt mixing aliphatic polyesteramide (PEA) with ordinary CaCO3, nano-CaCO3, and nano-SiO2. The effect of filler on the matrix was studied by mechanical properties and hydrolysis rate measuring. The ordinary filler as well as the nano-filler had a negative effect on the stability of the polymer melt, and an improved mechanical property was obtained around a critical concentration of the filler where a percolation phenomenon appeared. When the composites underwent hydrolysis, the inert filler played a role as a mechanical obstacle in the matrix and retarded the hydrolysis; on the other hand, the interfacial area between the filler particle and the matrix resin increased with the filler, which would accelerate the hydrolysis. As a result of these two inverse effects, a minimum and a maximum value appeared in the plot of the degradation rate-filler content graph. For the ordinary filler filled polymer, the filler retarded the hydrolysis; in great contrast, the hydrolysis rate of nano-composites showed a maximum value around the critical concentration of the filler, and was much higher than the neat resin.