聚氨酯弹性体分子结构对阻尼及力学性能的影响

Effect of molecular structure of polyurethane elastomer on damping and mechanical properties

为获得深水环境用减振降噪聚氨酯弹性体(PUE),选择甲苯二异氰酸酯(TDI)、聚丙二醇2000(PPG2000)和三乙醇胺(TEA)为原材料浇注制备了PUE,探究硬段含量、R值和合成方法对PUE阻尼性能和压缩模量的影响。结果表明:随着硬段含量的增加,PUE的tanδ峰值减小,压缩模量增强;随着R值的增加,Tg增大,压缩模量先增大后降低,R=2时达到峰值。预聚体法和一步法对合成出PUE的tanδ的影响较小,但预聚体法合成PUE的压缩模量明显优于一步法。增加分子链刚度、氢键化程度和硬段微区分布均匀程度可以有效提升PUE的压缩模量,但会导致阻尼性能下降。

In order to obtain polyurethane elastomer(PUE)for reducing the vibration and noisy in deep-water environments,toluene diisocyanate(TDI),polypropylene glycol 2000(PPG2000)and triethanolamine(TEA)were selected as raw materials,and the effects of hard segment content,R value and synthesis route on damping property and compression modulus of PUE were explored.Results reveal that the tanδof PUE could be decreased with the increase of hard segment content,while the compression modulus increases.With the increase of R value,Tg increases,the compression modulus first increases and then decreases,reaching a peak when R=2.The prepolymer process and one-step process have little effect on the tanδ,but the compression modulus of PUE synthesized by prepolymer process is obviously greater than that of one-step process,which is more in line with the requirements of high damping/strong pressure resistance.It was observed that the compression modulus of PUE can be effectively improved by increasing the stiffness of molecular chain,the degree of hydrogen bonding and the uniformity of hard segment micro region distribution,but for damping property have a negative impact.