Polyurethane (PU) is polyphenylene diisocyanate, polyether polyol, in the presence of catalyst triethylenediamine crosslinked curing and forming a high polymer. Polyamine ester has good adhesion and insulation. It can be applied to the packaging of various electrical and electronic equipment. Compared with epoxy resin, it has highly toxic. Epoxy resin is made of bisphenol A epoxy resins, curing agent, additives, fillers and other components. The curing time is longer at room temperature and it can be heated and cured. After curing, the adhesive strength is strong, and the hardness is generally larger. it used to package electrical modules and diodes. But polyurethane has better weather resistance that does not crack at high and low temperatures but is slightly more expensive.
Both have good tensile resistance, no cracking, no shedding and other properties. Both are resistant to corrosion of acid, alkali, salt and various oil substances. Both of them are dustproof, waterproof, surface wear resistance, stress resistance, impact resistance and other properties. The former paint is suitable for outdoor, while the latter is suitable for indoor. And latter biggest weakness and defect is to be afraid of strong ultraviolet ray illuminate, below strong ultraviolet ray illuminate can produce yellow change but won’t decompose also effect to use. However, the former is much better than the latter in terms of weather resistance, especially the yellowing time of the former is much longer than the latter, so the former is often used for outdoor construction requirements.