含烯醇-酮结构聚合物的合成及其在除甲醛涂料中的应用

Preparation of Polymer Containing Enol-Carbonyl Structure and Application in Coatings to Remove Formaldehyde

为了去除涂料中的甲醛,用3种丙烯酸型单体:丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)和3-羟基丁烯酸-2-甲基丙烯酸乙二酯(EMAHB)通过乳液聚合法合成了一种含烯醇-酮结构的功能聚合物(BA-MMA-EMAHB)。对不同单体比例的功能聚合物进行红外光谱比较,分辨出共聚物中的酯羰基和烯醇-酮基。以市售的普通乳胶漆(np120)作为空白涂料基底,分别加入不同单体比例的功能聚合物A、B和C,得到相应的除甲醛涂料,评价除甲醛涂料的贮存稳定性、黏度变化和交联度,发现功能单体EMAHB含量直接影响黏度增值和交联度,原因是缔合效应和酯交换反应。将除甲醛涂料涂覆于玻璃板上固化成膜,再在玻璃空气舱中进行除甲醛实验,发现功能聚合物的添加对涂料的除甲醛能力有较大的提升,其甲醛清除机理源于聚合物中烯醇基团对甲醛羰基的亲核反应。

To solve the problem of indoor air pollution caused by the formaldehyde, three functional polymers （A, B and C） with enol-carbonyl group were synthesized from the butyl acrylate （ BA）, methyl methacrylate （MMA） and 2- （methacryloyloxy） ethyl 3-hydroxybut-2 -enoate （EMAHB） at different monomer ratio by emulsion polymerization. The FT-IR spectrum was used to characterize the prepared polymers, which identified the two different carboxyl groups. Three formaldehyde-eliminating coatings were prepared by incorporating the polymer A, B and C respectively to a blank paint with its dosage of 1%, of which the storage stability, viscosity and crosslinking density were investigated. It was found that the content of monomer EMAHB had a direct impact on viscosity and crosslinking density of coatings because of molecular association effect and transesterification. The formaldehyde-eliminating coatings were coated on glass substrate to form cured films showing the improved performance in terms of formaldehyde elimination due to the nucleophilic reaction between enol group in polymer and carboxyl group in formaldehyde.