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Estimating the degree of functionalization in polypropylenes treated with peroxide in plant (polypropylene of controlled rheology) modified with acrylamide and diethylmaleate

Abstract:

In this paper, Polypropylene (PP), before and after being chemically modified with peroxide (PP-perox), in an industrial extruder of PROPILVEN Petrochemical Company, was characterized. Subsequently, PP was functionalized in solution with acrylamide (AAm) and diethylmaleate (DEM) in the presence of biperóxido (DBPH) as initiator. By spectroscopic analysis with Fourier transform infrared (FTIR) of functionalized (grafted) PP (PP-g-AAm and PP-g-DEM) revealed the presence of new functional groups from the DEM and AAm, indicating the effective insertion of both in the PP. In the spectra absorption was observed a band for both PP modified, assigned to stretching of the carbonyl groups (C = O) present. When the functionalized was done with DEM the band was observed around 1739 cm-1. To acrylamide was detected a band at 1666 cm-1 attributed to stretching of the same bond. Depending on the results, we determined the percentage of functionalization degree (% GF) using the calibration curve, which indicated the number of functional groups inserted in the chains of the PP. We found that for both grafting agents (DEM and AAm) the highest degree of functionalization was obtained when used the rheologically modified PP pre-treated with peroxide. From the results obtained in this work on GF is inferred that pre-treatment of PP with peroxide promotes the formation of grafts because: the molar masses are lower, or the presence of a greater number of activated centers in PP chains PP. © 2012 Universidad Simón Bolívar.