scientific achievements

Ø Three formulations have been developed for road wheel of MBT_ARJUNA. The performance of the compounds is very good compared to the road wheel supplied by MRF Ltd., Dunlop India Ltd., Madras Elastomers Ltd. (MEL), Sundaram Industries Ltd., and Imported wheel, Germany.

Ø To process these compounds, a new technology for transfer moulding and transfer mould has been developed at low cost. In this processes a special type of nozzle for transfer mould is designed to reduce transfer time of the compound during processing and to reduce the number of voids inside the materials.

Ø To get a best result, a special type of indigenously developed coating technology is applied on the aluminium rim. In this process, the bond strength tremendously increases.

Ø This project has been successfully completed and one of the three formulations is sent for bulk production.

Ø A model for hysteresis loss of polymeric materials under uniaxial loading and dynamic condition at medium stain (less than 100%) based on Boltzmann superposition principle, statistical theory of rubber elasticity and phenomenological theory. The hysteresis loss per unit volume for complete cycle can be represented as

where H_y, K^*, M^*, b, T_q, d, w, e₁, and n¢¢ are the hysteresis loss per unit volume for the complete cycle, material constant, material constant, volume expansion coefficient, temperature, phase angle, frequency, strain level, and integer respectively.

Ø I have proposed another model for energy (E_{Energy stored}) stored per unit volume in a quarter cycle based on Boltzmann superposition principle, statistical theory of rubber elasticity and phenomenological theory.

Ø I have proposed another model for quantification of hysteresis loss at very high strain based on Boltzmann superposition principle, statistical theory of rubber elasticity and phenomenological theory.

Ø I also proposed the energy stored per unit volume in a quarter cycle at very high strain as

Ø Another model equation to establish a new hypothesis that hysteresis loss of polymeric materials under dynamic condition is a function of relaxation time is also developed. The model is represented by the following equation.

Here , t_i, and n are material constant, relaxation time and integer respectively.

Ø I have developed a model equation relating heat generation per unit time per unit volume of filled polymeric materials (q) and hysteresis loss (H_y), specific heat (C_P), temperature difference between operating temperature (T¢) and glass transition temperature (T_g), frequency (n), stroke amplitude (SA), thermal conductivity of rubber (l), structure of carbon black (S_t), surface area of carbon black (S_a), Young’s modulus (M_o), weight of carbon black in rubber (F¢), temperature difference between wall and environment (DT), and stress i.e., load per unit area (S) as

Ø Recently, I have found out few dimension less groups to analyse heat generation of polymeric materials under dynamic conditions. These dimension less groups are derived from Buckingham p theorem and Rayleigh’s method.

Ø I have developed a polymer bonded magnet based on polyphenylene sulphide, vectra and magnetic powder (Nd-Fe-B) for high temperature and aggressive environments.

Ø I have investigated the role of magnetic particle morphology, concentration and distribution on the processing, and magnetization behavior of bonded magnets.

Ø However, the thermal stability of the rare earth magnetic powders at the desired temperature ranges has been improved by suitable surface treatments.

Ø The energy product has been improved by optimizing the fraction of magnetic powders and careful control of the particle morphology and particle size distribution.

Ø A fundamental understanding of the interaction between the polymer matrix and magnetic powders has been developed to improve the thermal stability of the powders.

Ø In addition, the rheological behavior of the polymer binder/powder mixtures is studied for improving processability.

Ø Based on the experimental data obtained, theoretical models have been developed to predict the optimal concentrations and distributions of magnetic powders.

Ø I have developed a high performance composites based on glass and general purpose plastics.