PDF《Acrylic-Epoxy Resins》

Study on the High Performance of Water-Borne Acrylic-Epoxy Resins Min LIU1 , Hua ZHU1* , Dihua WANG1 , Fuxin GAN1,2

1 School of Resource and Environmental Science, Wuhan University, Wuhan, China

2 State Key Laboratory for Corrosion and Protection of Metals, Shenyang, China Email: zhuhua333@126.

com Abstract: In this research, a two-step esterification synthesis process was adopted to prepare water-borne epoxy-acrylate resins, with Bisphenol A epoxy resins and different acrylic monomers being the reaction spe- cies. During the process, the acrylic polymerization was separated from the esterifications, so that the mo- lecular weight and carboxyl content of the modified resins could be controlled by changing the polymeriza- tion conditions. Acid values and epoxy equivalents were tested to monitor the extent of the first esterification. And GPC was employed to prove the realization of the synthesis process. Besides, water solubility, crosslinking degree and water absorption of the modified resins with different molecular weights and car- boxyl contents were determined to investigate their water resistance. Moreover, salt spray corrosion test was used to evaluate the corrosion resistance of the resins. The performance testing results showed that, the syn- thesized epoxy-acrylate resins had great water solubility, high crosslinking degree, good water resistance and corrosion resistance. When controlling the usage of methacrylic acid as 20% of the total acrylic monomers in the polymerization and the molecular weight of the modified resin as 7000, the optimum resin was prepared, which had a crosslinking degree above 99%, a water absorption below 6‰, as well as a great corrosion resis- tance verified by salt spray corrosion test for

500 hours. Keywords: Waterborne epoxy-acrylate resins;

water-based anti-corrosion coatings;

crosslinking degree;

water absorption;

two-step esterification;

molecular weight 高性能水溶性丙烯酸环氧酯树脂的性能研究 刘敏

1 ,朱华 1* ,汪的华

1 ,甘复兴 1,2

1 武汉大学资源与环境科学学院环境工程系,武汉,中国,430072

2 中国科学院金属腐蚀与防护国家重点实验室,沈阳,中国,110015 Email: [email protected] 摘要:采用二步酯化工艺,以双酚 A 环氧树脂及不同品种的丙烯酸酯类单体为原料,制备水性丙烯 酸环氧酯树脂.该工艺将聚合反应与环氧基开环酯化反应分步实施,从而实现对复合改性树脂的分子 量与羧基含量的控制.利用酸值及环氧值滴定结果确定一步酯化反应进行的程度;

采用凝胶渗透色谱 证明改性树脂的接枝成功;

此外,对不同分子量与羧基含量的改性树脂水性涂料的水溶性、交联度及 吸水率进行了考察;

同时,应用盐雾腐蚀测试及交流阻抗测试技术检测了其涂膜的耐蚀性能.结果表 明,通过该工艺制得的环氧丙烯酸树脂水溶性良好、交联度高、耐水耐蚀性能佳. 关键词:水性环氧丙烯酸;

水性防腐涂料;

交联度;

吸水率;

二步酯化;

分子量

1 引言 通常,成膜树脂的水性化通过在体系中引入极性 基团来实现.然而,高分子树脂实现水性化后,往往 会导致一些性能上的不足,如固化涂层附着力、耐水 耐蚀性等相关性能的下降.因此,如何在提高树脂水 溶性的同时,保证固化涂层的耐蚀性,成为了水性工 业防腐涂料开发的关键问题[1-2] .近年来,许多研究 者开展了多种树脂的复合研究,即采用接枝、酯化或 聚合等化学反应将两种以上的树脂进行复合,取长补 短,以期进一步提高水性成膜树脂的综合性能. 环氧树脂与丙烯酸树脂作为使用量大,互补性能 强的两类树脂,其复合技术被广泛关注[3-6] .根据 Matthews[7] 等人的研究,通过酯化接枝,将聚合后的 丙烯酸树脂在叔胺的参与下与环氧树脂反应,得到的 环氧丙烯酸树脂分子量更大,几乎没有游离的小分 子,且该方法工艺简单,具有工业化前景.但是,若 反应条件控制不当,易导致形成三维网络而出现凝胶 化,限制了其工业推广.而Ting、SpenCevrl[8-9] 等研 究者认为控制聚合反应条件,可以控制酯化反应程度 而避免凝胶. 因此,本文主要研究了能避免凝胶化,从而成功 将聚丙烯酸酯与环氧树脂进行接枝,同时过程稳定可 控的二步酯化工艺的实现,以及通过该工艺制备出来 的不同分子量及羧基含量的丙烯酸酯改性环氧树脂作 为水性涂料成膜树脂的相关性能.性能测试结果证实 自制的环氧丙烯酸水性树脂具备良好的耐水耐蚀性 能.