The synthesized method of the ETPU material(2)

The prepolymer method(ETPU material) is to synthesize oligomer diol and diisocyanate with dry chain extender under the condition of a small amount of catalyst. The process of prepolymer method is complex, energy consumption is high, and the viscosity of prepolymer is high, which increases the difficulty of process operation. However, the prepolymer has few side reactions, and the performance of the product is better than that of one-step method.

According to the continuity of the reaction process(ETPU material), it can be divided into batch method and continuous method. The common production equipment of batch process includes automatic pouring equipment, curing oven, crushing hammer, extruder, etc. its production efficiency is low, the product quality is uneven, and it is not suitable for large-scale production. Therefore, continuous production process and equipment have been studied at home and abroad. The continuous process equipment is a reactive extrusion production line, and its main equipment includes raw material storage tank, pouring machine, parallel twin-screw extruder, underwater pelletizer, separation and drying equipment and packaging equipment. Twin screw continuous reactive extrusion is the mainstream process of production at present. It has high production efficiency and stable product quality, and is suitable for large-scale production. Its products can be used in coatings, elastomers and adhesives