Fabrication of highly isotactic polypropylene fibers to substitute asbestos in reinforced cement composites and analysis of the fiber formation mechanism

Highly isotactic polypropylene (PP) is currently studied as a cement‐reinforcement fiber that could potentially be substituted for asbestos because of its resistance to prolonged high‐temperature curing. The higher the isotacticity of the PP fiber is, the higher the tensile modulus and breaking strength of the cured fiber are. The PP fiber that exhibits a isotacticity of 99.6% (XI) and draw ratio of 6.0 retains a tensile modulus of 4.23 GPa, even after high‐temperature curing at 175°C for 5 h. PP fiber is cut into 6‐mm lengths and dispersed throughout a cement mixture to prepare a reinforced cement composite. The mixture is cured in an autoclave at 175°C for 5 h. The Charpy impact strength and flexural strength of the obtained cement composite tends to increase with increasing PP isotacticity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 981‐988, 2013