Polyvinyl chloride (PVC)/ Halloysite (HNT) nanocomposites: Thermal stability and structural characterization studies
Selvin P. Thomas
Abstract
Due to its versatile properties polyvinyl chloride (PVC) based materials are employed in several applications. At high temperatures and in acidic media PVC is prone to release toxic materials into the environment. Several reports are available in the literature about the modification of PVC to minimize such problems. Herein, an attempt is made to prepare PVC/Halloysite nanotube (HNT) nanocomposites with a fixed amount of compatibilizer, OPTIM GE 344 (maleic anhydride modified very low-density polyethylene (VLDPE)) and characterize the composites with respect to thermal stability, mechanical properties, and structural aspects. Both tensile and flexural strength showed appreciable improvement for the 4 wt% loading of the nanofiller. Thermogravimetric analysis (TGA) showed that the maximum degradation temperature improved by approximately 24 °C for 4 wt% filled composites. PVC thermomat measurements of the samples were used to study the thermal stability of the composites. PVC without HNT showed 36 min as the stability time and it increased to 398 min for 4 wt% of HNT loading. To complement the thermal properties of the composites, the mass loss measurement and contact angle behavior of the composite surfaces were also done. The decrease in contact angle values denoted better surface wettability properties. The mass loss measurements showed a decrease with respect to the filler loading of HNT, indicating a better interaction between the polymer matrix and HNT.