3.4.2. Atomicforcemicroscopy(AFM)
To further explore the nature of interactions between PLA and PLA/MCC composites, the composites were observed by AFM, and the results are presented in Fig. 5. From the figure, it can be clearly seen that the inclusions of MCC into the PLA matrix significantly change the surface topography of the pure PLA. The pure PLA surface is relatively smooth (Fig. 5(a)). However for PLA/MCC com- posites (Fig. 5(b)–(d)) the cluster between PLA and MCC are readily apparent and the surface cluster a clearly observed when the MCC contents are increased. The cluster features are interpreted as the result of aggregation of the MCC, or as PLA coated MCC. Similar result was earlier reported by Saxena, Elder, Pan, and Ragauskas (2009).