Akademik Veri Yönetim Sistemi
Düzce Üniversitesi Bilim ve Teknoloji Dergisi, cilt.11, sa.3, ss.1327-1340, 2023 (Hakemli Dergi)
The purpose of this work is to improve mechanical properties of rigid polyurethane (RPU) composites used in
traditional ceramic casting industry. Therefore, monofilament (mono) and fibermesh (fibril) polypropylene (PP)
fibers with various lengths (3, 6, 12 and 18 mm) were incorporated to polymer matrix at different rates (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 (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.