The photoacoustic spectroscopy applied in the characterization of the cross-linking process in polymeric materials

In this work we used the Photoacoustic Spectroscopy (PAS) to evaluate the crosslinking of the copolymer from ethylene vinyl trimethoxysilane (EVS) and the grafted vinyl trimethoxysilane (VTS) on low density polyethylene (LDPE). PAS is used for sounding the overtone bands and stretching frequencies combinations of the groupings -Si-OH, =CH2, -CH3 and -CH2-CH3, in the near and medium infrared range. The samples were typically prepared with 3%, 5% and 7% of catalyst and crosslinked in the temperatures of 70, 80 and 90degreesC. Using the overtone bands of -OH groups the PAS shows the optimum combination, pointing a better crosslinking effect for 80degreesC and in the range 5% to 7% of catalyst, typically.