The effect of filler loading on the cure time (t90) and swelling behaviour of SMR L/ENR 25 and SMR L/SBR blends has been studied. Carbon black (N330), silica (Vulcasil C) and calcium carbonate were used as fillers and the loading range was from 0 to 40 phr. Results show that for SMR L/ENR 25 blends the cure time decreases with increasing carbon black loading, whereas silica shows an increasing trend, and calcium carbonate does not show significant changes. For SMR L/SBR blends, the cure time of carbon black, silica and calcium carbonate generally decreases with increasing filler loading. The percentage swelling in toluene and ASTM oil no 3 decreases for both blends with increasing filler loading, with calcium carbonate giving the highest value, followed by silica‐ and carbon black‐filled blends. At a fixed filler loading, SMR L/ENR 25 blend shows a lower percentage swelling than SMR L/SBR blends. © 2003 Society of Chemical Industry

This paper aims to study the feasibility of friction stir welding of thermoplastic material polyamide 6,6. The maximum joint strength achieved through the optimized process variables is 41 MPa. The maximum temperature rise of 126 °C is achieved and the weld nugget exhibits a hardness of 69 D on Shore hardness scale. Fractography analysis reveals that the fracture followed a continuous plastic flow comprising less prominent fibrillation and more elongated voids. An increase in glass transition temperature Tg is observed in the weld specimen. The impact of the welding process variables on the frequency and band shift of the functional groups of the polymer is also discussed.

This paper deals with the work done on friction stir welding of thermoplastic material PA 6,6. A specially designed welding tool was used for this polymer. The major process parameters like tool rotational speed, feed rate were varied to understand the physical changes of the polymer and to carry out characterization studies. In this study, an attempt was made to optimize the process parameters by using L9 orthogonal array approach. ANOVA analysis was used to explore the effect of process parameters. Tensile testing was performed to analyze the joint strength. Thus, in new exploration of using polyamide 6,6 as base material, a maximum joint strength of 37 MPa has been achieved. Optimum combination of process parameters were found by using ANOVA studies. Microstructure of the friction stir welded joints using scanning electron microscopy was done. The X-ray diffraction and the thermogravimetric analysis were done to determine the degree of crystallinity and the level of degradation of the friction stir welded joints.