Degradation of low density polyethylene (LDPE)
was studied for the pure polymer and mixed with silicoaluminophosphate
SAPO-11 catalyst. SAPO-11 was synthesized
by hydrothermal method using di-isoprolpylamine as
structure template, and characterized by XRD and SEM.
From X-ray diffraction, it was observed that SAPO-11 was
obtained with high crystallinity. Using the model-free
kinetics, proposed by Vyazovkin, the activation energies
were determined for the process of polymer degradation. It
was found that the degradation process of 90% of LDPE
mixed with SAPO-11 over a period of 1 h, occurred at a
temperature of 378 C, while for the pure LDPE, the
temperature was increased to 434 C in the same period of
time and conversion, indicating that SAPO-11 was an
effective catalyst for the degradation of LDPE. The activation
energy for the degradation of pure LDPE was
equivalent to 251 kJ mol-1. Also, when the SAPO-11 was
mixed with the polymer, this value was decreased to
243 kJ mol-1.