Navarathne, H.G.Senarathna, K.G.C.2021-02-252021-02-2520209789550481293http://www.erepo.lib.uwu.ac.lk/bitstream/handle/123456789/6081/proceeding_oct_08-443.pdf?sequence=1&isAllowed=yToday, there is a great need for the reduction of polyethylene waste to reduce environmental pollution. The main objective of this study is to develop a novel composite material using waste polyethylene reinforced with calcite to make polyethylene/calcite composite. Calcite taken from the Lanka Mineral and Chemicals (Pvt) Ltd. is used as the reinforcement for the composite and low-density polyethylene obtained from waste shopping bags is used as the polymer matrix. Sample series of octadecanoic acid-coated calcite powder and unmodified calcite nanoparticles are used to synthesis the composite. The in-situ deposition is used to synthesize nanoparticles from raw calcite. Calcite is incorporated into low-density polyethylene with different ratios and properties are characterized to obtain the optimum strength. Calcite powder is characterized using particle size analyzer, X-ray diffractometer, and Fourier transforms infrared spectroscopy. The composite is characterized by tensile tests, compression tests, and differential scanning calorimetry tests. Calcite nanoparticles obtained 23.2×10-9 m of average particle size after In-situ deposition. Only the polymeric material acquired 64.57×106 N m-2 of tensile strength and 44.62×106 N m-2 of compressive strength. Tensile strength is increased up to 69.87×106 N m-2 , 78.98×106 N m-2 , 66.41×106 N m-2 and compressive strength is reached to 90.58×106 N m-2 , 102.28×106 N m-2 , 75.98×106 N m-2 when polyethylene combined with raw calcite powder, calcite nanoparticles, and surfacemodified calcite powder (5:3 of polyethylene/calcite ratio) respectively. It provides evidence that the low-density polyethylene with calcite reinforcement attained to better mechanical properties than only the polymeric material. Keywords: Low-density polyethylene, Nanoparticles, Surface modified, In-situ depositionenMaterials SciencesMineral SciencesPollutionOther