Characteristics, Curing Mechanism, and Industry Application of Polyurethane Sealing Adhesive
159 2023-07-17
Polyurethane potting adhesive, also known as PU potting adhesive, overcomes the drawbacks of commonly used epoxy resin brittleness and low strength and poor adhesion of organic silicone resin. It has excellent water resistance, heat resistance, cold resistance, UV resistance, acid and alkali resistance, high and low temperature impact resistance, moisture resistance, environmental protection, and high cost-effectiveness. It is an ideal potting protection material for electronic components. Comprehensively meets certifications such as V0 flame retardant rating (UL) and environmental protection certification (SGS).


Characteristics of polyurethane potting adhesive

● Good electrical performance

● Excellent adhesion

● Low water absorption

● Halogen free

● Low mixed system viscosity

● non-toxic

● Long storage time

Curing Mechanism of Polyurethane Sealing Adhesive


For polyurethane adhesives, the curing process involves the complete reaction of NCO groups in the adhesive, or the complete volatilization of solvents, and the crystallization of polyurethane molecular chains, resulting in a sufficiently high bonding force between the adhesive and the substrate. Polyurethane adhesives can be cured at room temperature. For reactive polyurethane adhesives, if room temperature curing takes a long time, a catalyst can be added to promote curing. In order to shorten the curing time, Heating can be used. Heating is not only beneficial for the curing of the adhesive itself, but also for accelerating the reaction between the NCO groups in the adhesive and the active hydrogen groups on the surface of the substrate. Heating can also soften the adhesive layer, increase the infiltration of the substrate surface, and facilitate molecular movement. Finding a "partner" that generates molecular forces at the bonding interface is beneficial for improving the bonding force. A two-component polyurethane adhesive is used to bond steel plates, Adhesion strength at different curing temperatures and times


Industry Application of Polyurethane Sealing Adhesive


The main component of polyurethane (PU) potting adhesive is the cross-linking and curing of polyisocyanates and polyether polyols in the presence of a catalyst (triethylenediamine), forming a high polymer. The polyurethane adhesive has good bonding performance, insulation performance, and weather resistance. The hardness can be adjusted by adjusting the content of diisocyanates and polyether polyols, which can be applied to various electronic and electrical equipment packaging.



，Polyurethane potting adhesive is a sealant developed for long-term protection of precision circuit controllers and components in the electronic industry. It has excellent electrical insulation and is particularly suitable for sealing electronic circuit boards and components used in harsh environments such as damp, vibration, and corrosive environments. Suitable for sealing various electronic components, microcomputer control boards, etc., such as washing machine control boards, pulse igniters, electric bicycle drive controllers, Electric tools，etc.