EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES OF POLYURETHANE POWDER COMPOSITES

In this paper, the effects of emery, lime, quartz sand and cement on the mechanical properties of polyurethane powder composites were studied by three-point flexural test, and the stress-strain curve was drawn. In the flexural test, the polyurethane cement composite formed a control group by changing the content of polyester polyol. When polyester polyol: isocyanate: cement =1:1:2, the average flexural strength of polyurethane cement was 37.1 MPa, and the strain was 10854 με.When polyester polyol: isocyanate: cement =1.15:1:2, the average flexural strength is 38.9 MPa and the strain is 23520 με.When polyester polyol: isocyanate: cement =1.3:1:2, the average flexural strength is 42.5 MPa and the strain is 32942 με. The flexural strength and ductility are improved to a certain extent due to the addition of polyester polyol.The average flexural strength of other polyurethane powder composites such as polyurethane emery test block is 45.1 MPa and the strain is 6203 με, the average flexural strength of polyurethane lime test block is 33.4 MPa and the strain is 6470 με, the average flexural strength of polyurethane quartz sand test block is 49.23 MPa and the strain is 7521 με. The results show that the flexural strength of polyurethane emery material and polyurethane quartz sand material is higher than that of polyurethane cement, which can be used to replace cement to a certain extent to reduce the cost of polyurethane composite material.