Three kinds of two-component polyurethane waterproof coatings were prepared using different resins and curing agents and compared with a commercial acrylate waterproof coating.The curing agents are prepolymers synthesized by isophorone diisocyanate and polyether polyol (1000,2000 and 330N,respectively).The effects of resin type,curing agent amount (NCO/OH molar ratio) and proportion ofpolyether (mass ratio of 2000 to 330N) on mechanical properties of coatings were discussed.The results showed that all the 3 kinds of coatings prepared can meet the technical requirements of waterproof coating applied to concrete bridge of high speed rail.The No.2 and No.3 coatings,which were prepared from aromatic resin (diethyltoluenediamine) have larger tensile strength and elongation at break than the No.1 coating which is prepared from aliphatic resin (polyaspartate) and shows a better weatherability.The elongation at break of the three coatings is better than that of the normal acrylate coating.The No.3 coating prepared with the tri-functional polyether polyol330N has an increased tensile strength but a decreased elongation at break as compared with the No.2 coating.The tensile strength and elongation at break of the coatings tend to increase at first and then decrease with the increasing of NCO/OH value and 2000/330N mass ratio.%以异氟尔酮二异氰酸酯、聚醚多元醇1000、2000和330N为原料分别制备了预聚体作为固化剂,采用不同种类树脂及固化剂制备了3种双组分聚氨酯防水涂料,并与市售丙烯酸酯防水涂料进行比较.探讨了树脂种类、固化剂用量(NCO/OH摩尔比)、固化剂中聚醚配比(2000/330N质量比)对涂层力学性能的影响.结果表明,所制3种涂料均能达到高铁客运专线桥梁混凝土桥面防水涂料的技术要求,其中含芳香族基团的树脂(以二乙基甲苯二胺为原料)所制2#和3#防水涂层比脂肪族树脂(以聚天门冬氨酸酯为原料)所制l#涂层具有更大的拉伸强度和断裂伸长率,但后者的耐候性更好,它们的断裂伸长率均好于常用丙烯酸酯涂层.引入三官能团的聚醚330N使3#涂层的拉伸强度大于2#涂层,但是降低了其断裂伸长率;随着NCO/OH值及2000/330N质量比增大,涂层的拉伸强度及断裂伸长率均呈现先增大后减小的趋势.
展开▼
