On the Properties of New Polyurethane Fast-Curing Polymer Materials.

A sequences of unconfined compressive strength tests and flexural tests were conducted in this study to evaluate the curing performance of a new type of polyurethane sand fast-curing polymer material. The mechanical properties of the material were investigated under different curing temperatures (-10 °C to 60 °C), particle sizes (10-15 mesh, 60-80 mesh, 100-120 mesh, and 325 mesh), and material proportions (20% to 60%). Additionally, SEM analysis was employed to further reveal the reinforcement mechanism. The results demonstrated that the developed polyurethane polymer material exhibited superior curing properties and applicability across a wide temperature range of -10 °C to 60 °C. Both the compressive strength and flexural strength of the solidified sand increased with the increase in solidification temperature, resulting in improved curing effects. This material exhibited the best curing properties when using sand within the 100-120 mesh range. As the particle size decreased under the remaining specifications, there was a reduction in specimen strain and an increase in strength, while still maintaining favorable ductility. The optimal proportion for polyurethane material was 40%. Moreover, the nonlinear mathematical relationships between the strength and multiple influencing factors were established through multivariate regression analysis. The sand consolidation specimens exhibited X-shaped conjugate shear failure, which tended to occur at the weak interface between the sand and material. Lastly, Pearson's correlation analysis revealed a strong positive correlation between temperature and material content with strength.