SYNTHESIS OF ADDITIVES FROM MONTMORILLONITE TO MODIFY HDPE FINAL PROPERTIES

MONASTERIO, F.E.; DESTÉFANIS, H.A.

MACROMOLECULAR SYMPOSIA

WISLEY

Año: 2010

1022-1360

This work brings about the modification of sodium montmorillonite clay (MNa) by the cationic exchange with hexadecyltrimethylammonium to turn it into organophilic clay (MC16).Subsequently, MC16 was treated with silanes. Three silanes with functional groups of different chemical nature were used. The objective was to determine if the clay could affect high density polyethylene (HDPE) final behavior after being modified with each silane. The following silanes were used:Cl2Si(CH3)2, Cl2Si(CH3)(C6H5) and Cl2Si(C6H5)2. Finally, in situ hydrolysis was carried out to generate the respective siloxanes. These materials were characterized by XRD, FTIR and GPC analyses.Each one of these additives was mixed using melt compounding processing in a Haake torque rheometer Rheocord 9000 equipped with a mix chamber and roller rotors at 100 rpm and 190 °C. All hybrids were characterized by XRD, SEM and thermogravimetric analyses. Barrier properties to cyclohexane were also determined by pervaporation experiments.Results from all studies showed that the addition of approximately 3wt% of clay has changed the macroscopic properties of the above-mentioned composites, as compared with pure HDPE. This can be explained considering the different polymer/filler interactions which take place in each system.