Thermal and mechanical properties of investment casting pattern material based on paraffin wax fortified with LLDPE and filled with PMMA Robert Kimutai Tewo1,2, Hilary Limo Rutto1, Walter Wilhelm Focke2, Shatish Ramjee2, Tumisang Seodigeng1 1Department of Chemical Engineering, Vaal University of Technology, Private Bag X021, Vanderbijlpark, 1911, South Africa. 2Institute of Applied Materials, Department of Chemical Engineering, University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa. Abstract The thermal and mechanical properties of paraffin wax, linear low-density polyethylene (LLDPE) and poly (methyl methacrylate) (PMMA) microbeads formulations were prepared via extrusion process. The blends were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and its tensile properties (stress at break, strain at break and modulus of elasticity and). The results indicated that both LLDPE and PMMA had an influence on the thermal properties and the tensile properties of the blends. The TGA analysis showed that the thermal stabilities of the developed polymer increased and also at temperatures above 600 °C, there was no residue. DSC curves of the blends indicated two main exothermic peaks at 60 °C and 120 °C. This could be probably due to the wax structure and the LLDPE peak structure. DSC curves further suggested that the compatibility of the paraffin wax/LLDPE two phases increased with an increase in the filler content. The bending stress at break and the Young’s modulus increased with increasing LLDPE content whereas the PMMA beads increased modulus there was no gradual strain increment. Key words: Investment casting pattern, paraffin wax, LLDPE, PMMA, thermal stability, tensile testing