Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Mechanical Engineering

First Advisor

Sriram Sundararajan


Worldwide potential demands for replacing petroleum derived raw materials with renewable plant-based ones in the production of valuable polymeric materials and composites are quite significant from the social and environmental standpoints. Therefore, using low-cost renewable resources has deeply drawn the attention of many researchers. Among them, natural oils are expected to be ideal alternative feedstock since oils, derived from plant and animal sources, are found in profusion in the world. The important feature of these types of materials is that they can be designed and tailored to meet different requirements. The real challenge lies in finding applications which would use sufficiently large quantities of these materials allowing biodegradable polymers to compete economically in the market. Lack of material and tribological characterizations have created an awareness to fulfill this essential objective.

In order to understand the viability of biobased polymers in structural applications, this thesis work elucidates the study of friction and wear characteristics of polymers and polymeric composites made out of natural oil available profusely in plants and animals. The natural oils used in this study were soybean and tung oil. Various monomeric components like styrene, divinely benzene etc. were used in the synthesis of biobased polymers through Rh-catalyzed isomerization techniques. For the different polymeric composites, spent germ, a byproduct of ethanol production, is used as the filler and an organoclay called montmorillonite is used as the reinforcing agent in the polymer matrix. The effect of crosslinker concentration, filler composition and reinforcement agent concentration was studied under dry sliding. A ball-on-flat tribometer with a probe made out of steel, silicon nitride or diamond was used for most of the experimental work to measure friction and generate wear. The wear tracks were quantified with an atomic force microscope and a contact profilometer. The wear morphologies were studied with a scanning electron microscope. Thermosetting epoxy resin was used as a benchmark material to compare the tribological characteristics of the biobased polymers. Synthetic polymeric materials made out of norbornene monomers were also subjected to friction and wear tests. An empirical relationship between wear behavior and crosslinking was established.


Copyright Owner

Satyam Kumar Bhuyan



Date Available


File Format


File Size

178 pages