Effect of Polypropylene Fiber Type, Content and Length on Mechanical Performance of Rigid Polyurethane Composites

The purpose of this work is to improve mechanical properties of rigid polyurethane insert ignore into journalissuearticles values(RPU); composites used in traditional ceramic casting industry. Therefore, monofilament insert ignore into journalissuearticles values(mono); and fibermesh insert ignore into journalissuearticles values(fibril); polypropylene insert ignore into journalissuearticles values(PP); fibers with various lengths insert ignore into journalissuearticles values(3, 6, 12 and 18 mm); were incorporated to polymer matrix at different rates insert ignore into journalissuearticles values(0.5, 1.0, 1.5 and 2% by weight);. Effects of fiber type and content on flexural strength, bending strength and compressive strength of composites were investigated. Surface morphology and thermal characteristics of composites were evaluated by SEM and TGA analysis, respectively. Bulk densities of specimens with and without PP fibers vary between 72,15-146 kg/m3. Compared to pure rigid polyurethane foam, bulk density of monofilament PP reinforced composites significantly increased and the highest density value insert ignore into journalissuearticles values(146,86 kg/m3); was reached in M6/2.0 sample. On the other hand, incorporation of fibrilmesh caused a decrease in bulk density. While the increase in percentage of mono PP increased flexural strength, the presence of fibril PP had a negative effect on strength. Compressive strength of all mono PP reinforced composites is higher than that of pure RPU, except for M6/0.5 sample. Besides, SEM analysis revealed that the presence of PP fibers generally reduced number of closed cells in composite structure. Experimental findings indicate that fiber type, content and length affect mechanical performance of RPU composites. In addition, it is possible to use mono PP fiber reinforced RPU composites as support apparatus in ceramic casting industry.