A comparative thermal, optical, morphological and mechanical properties studies of pristine and C15A nanoclay-modified PC/PMMA blends: a critical evaluation of the role of nanoclay particles as compatibilizers

The role of organically modified nanoclays as compatibilizers for PC/PMMA blends has been investigated using thermal, optical, morphological and mechanical properties studies. The observation of single Tg, whose composition dependence shows negative deviation with respect to the additive and Fox laws, suggests the compatibilizing action of organically modified nanoclay. A significant decrease in opacity also points towards the compatibilizing action of nanoclay. The crossover from a two phase morphology of pristine blends to homogeneous morphology in the presence of nanoclay also indicates compatibilization. 1H NMR results rule out the possibility of ester-carbonate exchange reaction between PMMA and PC in the presence of organically modified nanoclay proposed by earlier researchers. The mechanical properties studies reveal that nanoclay-modified blends have a higher Young's modulus than the pristine blends, possibly due to the reinforcement effect of the clay nanoparticles. However, the brittleness of the blends raises doubts about the compatibilization as it indicates poor interfacial adhesion between the nanoclay particles and polymer phases leading to poor stress transfer ability across the interface.