Investigation on the Effects of Nanoclay and Nano Calcium Carbonate on Properties of Binary and Hybrid Nanocomposites Based on PLA

Polylactic acid (PLA)/nanoclay, PLA/nano calcium carbonate (NCC) and PLA/nanoclay/NCC binary and hybrid nanocomposites were prepared via melt mixing containing 1, 2, and 3 wt% nanoclay and 5, 7 wt% NCC. It was observed via X-ray diffraction that nanoclay interlayer distance was enhanced from 1.8 nm to 3.26 nm indicating intercalation in binary samples. Interlayer distance was increased more in presence of NCC comparing to binary PLA/nanoclay samples. Rheological studies showed an increase in the storage modulus of samples at low frequencies comparing to neat polymer. Modulus was less increased in NCC containing binary and hybrid samples at higher amounts of NCC. An improvement in complex viscosity of all samples was observed and the highest increase was witnessed for hybrid sample containing 5 wt% NCC. According to Differential Scanning Calorimetry results, crystalline temperature of hybrid sample containing 7 wt% NCC was about 8 °C higher than that of neat sample.