. On the other hand, the commercial clay gives a better exfoliation than the laboratory ones, and the close contact with the polymer is necessary for the clay action on the degradation. Moreover, the TEM analysis reveals that the two clays modified in the laboratory appear in the composite surrounded by dark impurities, tentatively explained as degraded rests of the chemical modifications of the clays, which hinder the close contact with the polymer.
The degradation of polycarbonate also depends on the amount of clay and the processing temperature. However, the apparent water content of the clay does not appear to play a significant role in this case.
The obtained results indicate that the degradation of PC during the melt processing of the clay-reinforced nanocomposites may be characterized using fluorescence emission and UV absorption spectroscopic techniques. The clays modified by us in the laboratory cause substantially less degradation of the polymer than the commercial clay used as a reference.
Acknowledgments
The valuable aid of Juan Luis Baldonedo, of the Centro Nacional de Microscopía Electrónica (ICTS-CNME), for obtaining the TEM images is gratefully acknowledged. The authors acknowledge also the financial support of the Ministerio de Ciencia e Innovación (MICINN) (project MAT2010-19883), the Comunidad de Madrid (project CCG10-UPM/MAT-5569) and the Cátedra Repsol-UPM. J. Arranz-Andrés is grateful to the CSIC JAE-Doc Program for his financial support.