摘要
降低固化环氧树脂吸水性能是提高其可靠性与寿命的重要前提之一.我们曾将常用的线型酚醛树脂(phenol novolac resin,NOV)中吸水性较强的羟基用乙酸基取代,制成乙酸线型酚醛酯树脂(phenol novolac acetate resin,NOVA),并作为邻甲酚环氧树脂(epoxy o-cresolnovolacresin,ECN)的新型固化剂.我们用称重法研究,发现采用NOVA代替NOV所得的新型固化环氧树脂样片的饱和吸水率(M_∞)可降低一半以上.环氧涂层一般很薄,难以称重法研究其吸水性能,我们改用电化学阻抗法(EIS).本文报导用此法研究上述新型环氧涂层的吸水性能所得的一些有兴趣的结果,并作出了初步的解释.1.实验ECN采用日本东都公司YDCN-702p,NOV采用日本住友公司H-1,NOVA由本实验室自制,固化促进剂采用2-甲基咪唑(武汉制药厂).固化树脂以混合固化剂中NOVA与NOV的摩尔比命名,如n(NOVA)/n(NOV)(1:2)表示固化剂中NOVA和NOV的摩尔比是1:2.
The lowering of the water sorption of the epoxy coating by replacing the hydroxyl groups in the coating with acetoxy groups has been studied using electrochemical impedance spectroscopy. The experimental results show that the lowering of the water sorption at the coating/substrate interface of the novel epoxy coating is much larger than that in the bulk of the coating. This may be attributed to the surface bond formation which makes the orientation of the acetoxy groups at the interface different from that in the bulk, and causes the coating near the interface less hydrophilic.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1999年第3期329-332,共4页
Acta Chimica Sinica
基金
国家自然科学基金(29573100)
关键词
环氧树脂
吸水性
电化学阻抗谱
涂层
腐蚀防护
epoxy resin, water sorption, electrochemical impedance spectroscopy
