In this study, the effect of crosslinking density of an acrylic-melamine clearcoat on water vapor transmission rate was evaluated. Four types of acrylic resins with different OH contents were used as the main polymeric backbone of the acrylic-melamine clearcoat. Also, three different acrylics to melamine–formaldehyde ratios were used in the coating formulations to obtain various crosslinking densities. It was observed that other film properties such as surface hydrophilicity and molecular homogeneity had a crucial impact on the clearcoat water vapor transmission rate together with the crosslinking density. Surprisingly, results showed that samples with acrylic resin with less OH content and lower melamine–formaldehyde crosslinker had the lowest water vapor transmission rate among other samples. These results were in agreement with the water contact angle and the data deduced from dynamic mechanical thermal analysis (DMTA) results of clearcoats.

在这项研究中，评估了丙烯酸-三聚氰胺清漆的交联密度对水蒸气透过率的影响。四种具有不同OH含量的丙烯酸树脂被用作丙烯酸-三聚氰胺透明涂料的主要聚合物主链。另外，在涂料配方中使用了三种不同的丙烯酸与三聚氰胺-甲醛比率，以获得各种交联密度。观察到其他膜性能，例如表面亲水性和分子均质性，对透明涂层的水蒸气透过率以及交联密度都具有至关重要的影响。出乎意料的是，结果表明，丙烯酸树脂的OH含量较低，三聚氰胺-甲醛交联剂含量较低，其水蒸气透过率最低。