Polyethylene Mechanical properties 33 Composite materials 25 Polypropylene 25 Testing 16 Thermoplastics 16 Polymeric composites 10 Analysis 8 Artificial joints 8 Materials 8 Recycling 8 Nanocomposites (Materials) 7 Plant fibers 6 Reinforced thermoplastics 6 Standards 6 Strenght of materials 6 Bricks 4 Compression testing 4 Fillers (Materials) 4 Pipe 4 Plastics in medicine 4 Polylactic acid 4 Thermoplastic composites 4 Bentonite 3 Conducting polymers 3 Fibrous composites 3 Polythiophenes 3 Therapeutic use 3 therapeutic use 3 Adhesion 2