基于不同杨氏模量的聚氨酯基防结冰涂层的制备及研究

Preparation and Research of Polyurethane Based Anti-icing Coating Based on Different Young’s Modulus

以4,4'-二苯基甲烷二异氰酸酯(MDI)、聚四氢呋喃醚二醇(PTMEG)为原料,通过改变R值,获得了不同杨氏模量(0.72~5.95 MPa)的单组份湿固化型聚氨酯弹性体(PUE)涂层,用不同分子量聚醚二元醇进行对比,探究涂层杨氏模量对冰黏附强度的影响.结果发现,较高分子量聚醚二元醇系列具有较低冰黏附强度(平均57.71 kPa),随涂层杨氏模量增大,对应冰黏附强度呈先增大后减小趋势.分析表明,低杨氏模量涂层(如PTMEG-1000作软段时,1.05~2.96 MPa)在水结冰膨胀过程中,涂层表面易产生变形,形成凹凸不平结构,提供更多黏附点供冰结构黏附,使得冰黏附强度与表面能密切相关,造成冰黏附强度增大的可能性.而较高杨氏模量涂层(如PTMEG-1000作软段时,2.96~5.95 MPa)存在冰黏附强度的降低区间不符合杨氏模量与冰黏附强度的正相关关系,这是因为受低温回弹力作用,冰与涂层产生弹性失配,诱发产生微裂纹使得冰-涂层界面空化,造成冰黏附强度减小的可能性.因此,合理利用涂层杨氏模量对冰黏附强度的影响机制可以有效降低冰黏附强度.

Using 4,4'-diphenylmethane diisocyanate(MDI)and polytetrahydrofuran ether diol(PTMEG)as precursors,a one-component wet-cured polyurethane elastomer(PUE)coating with tunable Young’s modulus(0.72-5.95 MPa)was synthesized by manipulating the R value.The effect of Young’s modulus of coating on ice adhesion strength was studied by comparing polyether diols with different molecular weights.The results show that higher molecular weight series of polyether diols exhibit lower ice adhesion strength(average 57.71 kPa).As the Young’s modulus of the coating increases,the corresponding ice adhesion strength initially rises and then declines.The analysis reveals that the surface of the coating with low Young’s modulus(for example,PTMEG-1000 as the soft segment,1.05-2.96 MPa)is easily deformed during water icing expansion,forming uneven structures and providing more adhesion points for the ice structure to adhere,which makes the ice adhesion strength closely related to the surface energy,resulting in the possibility of increasing the ice adhesion strength.However,the decrease interval of ice adhesion strength in coatings with higher Young’s modulus(for example,PTMEG-1000 as the soft segment,2.96-5.95 MPa)is not consistent with the positive correlation between Young’s modulus and ice adhesion strength.This is due to the effect of low temperature resilience,the elastic mismatch between the ice and the coating induces micro-cracks and cavitation of the ice-coating interface,resulting in the possibility of reducing the ice adhesion strength.Therefore,understanding how coating’s Young’s modulus affects ice adhesion can be effectively utilized to reduce such adhesive properties.