MDI和硅油改性环氧树脂及配制富镁底漆性能

The properties of epoxy resin modified by MDI & Silicon-oil and magnesium-rich coating

摘要:

本文研究了一种二苯基甲烷二异氰酸酯（MDI）和羟基硅油共同改性环氧树脂的方法，利用MDI的桥接作用首先合成了MDI－羟基硅油预聚物，通过红外光谱以及稳定性分析确定预聚物最佳合成工艺；而后通过连续滴加工艺实现预聚物对环氧树脂的改性，通过红外光谱、GPC测试以及稳定性分析详细考察了催化剂用量、反应时间以及反应物配比对改性树脂性能的影响，优化改性工艺。研究表明，树脂和预聚物合适的配比为4:1（质量比），有机锡催化剂合适用量为0.5%（占总体系），反应时间4h；进一步，利用改性树脂配制富镁涂层，通过涂层基本性能测试，盐雾试验和老化试验研究涂层对铝合金的保护性能。研究表明，涂层具有高的附着力、柔韧性和耐冲击性，耐盐雾和耐老化性能优越。

Abstract:

In this paper, a method of modifying epoxy resin with MDI and hydroxy silicone oil was studied. Firstly, MDI-hydroxy silicone oil prepolymer was synthesized using the bridging effect of MDI, and the optimal factors to prepare prepolymer were determined by IR testing and stability analysis; Then, the epoxy resin was modified by the prepolymer through continuous dropping process. The effect of catalyst’s amount, reaction time and reactant ratio on the modified resin was investigated in detail through IR, GPC testing and stability analysis to optimize modification factors. The results have shown that appropriate ratio of resin and prepolymer is 4:1 (mass ratio), appropriate amount of organotin catalyst is 0.5% (accounting on the total system), and reaction time is 4h; Further, Mg-rich coating was prepared using the modified resin, and protective performance for aluminum alloy was studied through basic performance testing of coating, salt spray testing and aging testing. The results have shown that Modified epoxy resin-Mg rich coting has high adhesion, flexibility and impact resistance, especially, the salt spray resistance and aging resistance were excellent.