DMA - Poject1

5. Dynamic Mechanical Analysis (DMA)

5.1. Storage Modulus (E’)

The storage modulus verses temperature of the virgin matrix and nanocomposite hybrid is represented in figure 4a.

Figure 4a: Storage modulus for PBAT and its Bio-nanocomposite

It is evident that storage modulus of PBAT biopolymer increases with incorporation of nanofiller which is probably due to the efficient stress transfer from the filler to matrix. Further the grafted sample exhibited improved modulus as compared with the ungrafted nanocomposite hybrids. This further confirms improved interface between the nanofiller and the biopolymer matrix upon functionalisation with MA. MA-g-PBAT/B109 sample exhibited optimum storage modulus as compared with MA-g-PBAT/C30B nanocomposite hybrid, which is probably due to better exfoliated structure. In all the samples storage modulus (E’) decreases with the increase in temperature and there is a drastic fall in the modulus beyond –20°C, which possibly corresponds to Tg of the Biopolymer. However in case of the nanocomposite hybrid the rate of fall of matrix modulus has been compensated by the interactions caused due to the presence of the nanoclays in the system which further shows an increase in the thermal stability of biopolymer with the addition of layered silicate.