自流平聚氨酯的制备及阻尼甲板的降噪性能

为降低船舶甲板的振动和空气噪声,以支化和线性多元醇,低粘度聚合多异氰酸酯(PMDI)为主要原料制得阻尼聚氨酯,并将其铺设于钢甲板与浮动甲板之间。 探讨了基体结构、阻尼填料等对阻尼层固化时间、流平、阻尼和力学等性能的影响,以及铺设阻尼层前后甲板整体的隔声性能。 结果表明,调节支链和线性多元醇的质量比,可以改变基体的交联程度与结构,支化多元醇提高了聚氨酯的固化速率,硬度,以及力学性能;线性多元醇降低了体系的玻璃化转变温度,使阻尼温域移向低温,损耗因子峰值提高。 铺设于现有浮动甲板结构下2 mm聚氨酯阻尼层,可以有效增加整个甲板平均3 dB的隔声量,且在低频区增加量更大。 制得的聚氨酯阻尼层流动性优越,室温固化时间可控,可方便快捷的一次性自流平施工,对于提高现有浮动甲板的降噪性能具有实际的意义。

Preparation of Self-leveling Polyurethane and Sound Insulation Performance of Damped Decks

In order to reduce the vibration and air noise of ship deck, damping polyurethane was prepared from branched and linear polyols and low viscosity polymethylene polyphrnyl polyisocyanate(PMDI), and laid between steel deck and floating deck. The effects of matrix structure and damping filler on the curing time, leveling, damping and mechanical properties of damping layer were studied. The sound insulation performance of decks before and after laying damping layer was discussed. The results show that adjusting the mass ratio of branched and linear polyols can change the degree of crosslinking and the structure of the matrix. Branched polyols improve the cure rate, hardness, and mechanical properties. Linear polyols reduce the glass transition temperature of the system. The damping temperature range appears at high temperature and the loss factor peak value increases. A two-milimeter-thick polyurethane damping layer under an existing floating deck structure effectively increases the average sound insulation by 3 dB, and the effect is greater in the low frequency range. The polyurethane damping layer has excellent fluidity, controllable curing time and convenient self-leveling construction, which is of practical significance for improving the sound reduction performance of the existing floating deck.