Page 142 - 2025水性涂料虚拟专辑
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罗海航等:可紫外固化的水性聚氨酯耐沾污涂层
microscopy(AFM),and was also tested for self-cleaning,anti-graffiti and corrosion
resistance. It was found that PDMS,as a branched chain,was able to enrich on the surface of
the coating during curing to form a hydrophobic layer,eading to an increase in the contact
l
angle of the coating for water and diiodomethane from(70. 0±2. 4)°/(33. 6±2)° to(93. 8±
r
r
1. 2)°/(62. 2±1. 1)°,espectively,educing the wetting and spreading of contaminants. On one
t
hand,he introduction of cross-linking agents EOTA could effectively wrap around the polar
groups of polyurethane and reduce the polarity of the coating surface,which weakened the
interaction force between pollutant small molecules and the coating. As a result,water and oily
droplets could easily slide off the surface of the coating without leaving any traces,and the
t
coating showed good self-cleaning properties of the coating. On the other hand,he dense
cross-linking network also prevented the penetration of contaminant molecules such as inks
into the polymer backbone,making these inks and other pollutants stay on the surface of the
coating and shrink into tiny droplets. The pollutant traces had been wiped away,showing good
anti-graffiti performance of the coating. Not only that,after soaking in 10%NaCl solution for
5 days,the surface of the prepared coating was still smooth and maintained anti-graffiti
properties,howing good corrosion resistance and stain-resistant durability of the coating.
s
Key words:waterborne polyurethane;polydimethylsiloxane;UV curing;tain-resistant;
s
coating
耐沾污涂层对固体和液体污染物都具有较强的 酸酯三聚体为交联剂,单羟基封端聚二甲基硅氧烷
排 性,可防止污染物在基材表面润湿、铺展或附 (PDMS-OH)为疏水材料,在 100 ℃下固化 1. 5 h 得到
着。当涂层有一定的倾斜角度时,这些污染物可以 了一种PU防涂 自清洁涂层。虽然取得了良好的效
迅速滑出表面,且不会留下任何痕 ,展现出良好的 果,但长时间的高温固化不仅生产效率低下,而且能
自洁性。因此,这些涂层被应用于玻璃幕墙、 塑、 耗高,增加生产成本。不仅如此,高温固化涂层也限
金属、塑料、木材和皮革等基材表面 [1-4] ,不仅大大减 制其在热敏基材上的应用。另外,大多数 PU 耐沾污
少了昂贵的维护和清理费用,还避免了清洁人员在 涂料以溶剂型为主,有机溶剂的排放会对施工人员
高空作业时的潜在危险。不仅如此,这类材料还可 和环境造成较大的危害。因此,开发一种在温和条
以保护金属免受化学试剂的腐蚀 [5-7] 。 件下固化的环保型 PU耐沾污涂料已成为研究热点。
聚氨酯(PU)是一种常见的高分子材料,由于其 根据构建聚合物耐沾污涂层的 3 个原则,本研究
高透明度和良好的热力学性能及柔韧性等特点 [8-11] , 制备了一种基于紫外固化的水性聚氨酯耐沾污涂
近年来在涂料领域得到了快速的发展。但因其耐沾 层。首先选择单端双羟基聚二甲基硅氧烷(PDMS)
污性差,限制了PU在墙体防涂 、金属防腐以及窗户 作为疏水组分,接枝到 PU 侧链以降低污染物在涂层
自清洁等场景的应用。王振亚等 提出了构建聚合 表面的润湿铺展能力;然后以烯丙基羟乙基醚(AOT)
[12]
物耐沾污涂层的三要素,即低表面能、高交联度和弱 作为封端剂,引入潜在的交联点,制得含有机硅侧
客体- 主相互作用力。低表面能可降低液体在涂 链、烯丙基封端的水性聚氨酯(WPU-g-PDMS x );最
层表面上的润湿铺展能力;高交联密度可以有效阻 后,加入的交联剂乙氧化三羟甲基丙烷三丙烯酸酯
止污染物小分子渗透到聚合物骨架中并防止表面重 (EOTA)在紫外光和引发剂的作用下与 WPU-g-
构;而弱的 (污染物)主(涂层)作用力,则有利于污 PDMS 的烯丙基发生固化交联反应,形成耐沾污涂
x
染物的去除。 代东等 使用环氧大豆油和 2,2 双 层。进一步对耐沾污涂层的疏水性、表面能、透光
[13]
(羟甲基)丙酸合成了一种高羟值生物基多元醇 性、自洁性、防涂 性能及耐沾污持久性等进行了
(ESOD)。并以 ESOD 为羟基组分,六亚甲基二异氰 研究。
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