ENHANCED THERMAL PROPERTIES OF HYDROGEL-CLAY NANOCOMPOSITES

ROMINA OLLIER; LAURA SANCHEZ; JIMENA GONZÁLEZ; VERA ALVAREZ

Cancún

Conferencia; 33rd Annual Meeting of the Polymer Processing Society (PPS33); 2017

Hydrogels are one of the most widely employed materials in biological, medical and technological areas. They consist essentially on a low-cost and hydrophilic soft polymer, which forms a three-dimensional network and has the ability to absorb a large amount of water. In particular, the cryogels of polyvinylalcohol (PVA) constitute an eco-friendly alternative due to they can be obtained by a physical crosslinking method (through freezing/thawing cycles, F-T) thus avoiding the use of potentially harmful components. However, the use of hydrogels sometimes is restricted due to their specific properties. It is well-known that polymeric nanocomposites reinforced with clays show valuable improvements in their mechanical properties, heat resistance and gas permeability, regarding conventional micro and macrocompounds1. This is due to the large contact area between the matrix and the filler2. Composite hydrogels will be prepared employing PVA and bentonite (abundant and low cost smectite-type clay in Argentina) as raw materials through the previously optimized F-T crosslinking method. Different nanocomposite hydrogels will be obtained by varying the corresponding reactor feed. These materials have been recently chemically, morphologically and mechanically analyzed by our group3. Specifically, in the present work, thermal degradation behavior of PVA-bentonite hydrogels will be studied. Kinetic analytical models4 will be applied to non-isothermal thermogravimetric (TGA) measurements trying to identify the possible mechanism for PVA degradation in the presence of bentonite.