Event:182nd Technical Meeting Location: Cincinnati, OH Date: October 09, 2012 Author: Hanna J. Maria, Nathalie Lyczko, Ange Nzihou, Kuruvilla Joseph, Cherian Mathew, Sabu Thomas Paper Number: 54
Blends of different polymers have significant influence in industrial applications. Understanding the role of nanofillers in immiscible blends is one of the key factors in modifying the morphology, interphase and ultimate property of polymer blends. Addition of organically modified clay was found to improve the mechanical property of the blend system Presence of clay in the immiscible NRINBR system thus showed compatibilizing action. While dealing with the service performance it is necessary to study the time dependent properties such as stress relaxation and creep. In the research described, different compositions of natural rubber and nitrile rubber blend nanocomposite vulcanazite with different clay loading were prepared in an attempt to study the effect of nanoclay on the stress relaxation behavior of these elastomer blends. The effects of clay loading, blend composition, filler polarity and temperature on stress relaxation were carefully measured. Based on the stress relaxation measurements it was observed that Mercapto modified clay has more affinity with natural rubber in the blend system and Cloisite 10A due to its polarity was preferentially located at the NBR phase. The preferential localization of the clay has been analysed by HRTEM The nature of interaction of the nanoclay was found to influence the stress relaxation rate. Blend nanocomposites with higher filler loading showed higher rates of relaxation rate due to the presence of more filler-filler interactions. At 70 DC the viscosity ratio was found to influence the reinforcement and consequently relaxation rate of the 50l5O blend nanocomposite. The polarity of the filler and polymer was also found to influence the stress relaxation behaviour. It was found that the rearrangements of the polymer chains are dependent on the blend composition, temperature, fillerlpolymer interactions etc. The stretched- exponential Kolrousches equation and the three elements Maxwell-Weichert model with three relaxation times were used to model the relaxation behavior and for both models the experimental curve fitted well with the theoretical models.
By Hanna .J. Maria, Nathalie Lyczko, Ange Nzihou, Kuruvilla Joseph, Cherian Mathew, Sabu Thomas