The tensile strength and elongation at break of DMBA polyurethanes are higher than that of DMPA polyurethanes. The reason is that: First, the molecular structure of DMBA, the huge side chain -CH2COO- hindered the aggregation of hard segments of polyurethane, and the hardness of hard segments was poor, making the hard The segment itself has a higher solubility in the soft segment matrix and a hard segment in the hard segment micro region. These factors will result in a decrease in the modulus, whereas a low modulus will result in a greater elongation at break, in turn a greater elongation at break. This will cause further stress crystallization of the soft segment, resulting in higher tensile strength. The second is that DMBA has a lower melting point than DMPA, and DMBA easily melts to the polyol. Therefore, DMBA can react completely according to the formula in the same time. Since only a part of DMPA dissolves, DMBA has a higher molecular weight than DMPA. Better mechanical properties. The reason that gloss of DMBA is higher than that of DMPA may be due to the fact that DMBA is more hydrophilic, resulting in a smaller particle size of the emulsion and more uniform particles.