Four advantages of epoxy glue:
(1) Contains a variety of polar groups and highly active epoxy groups, so it has excellent adhesion to a variety of polar materials such as metal, glass, leather, wood, plastics, etc., especially materials with high surface activity.
(2) No low molecular volatiles are produced when epoxy resin glue is cured, and the shrinkage rate after curing is small, about 1% to 2%. It is one of the thermosetting resins with the smallest curing shrinkage rate. plus
It can be reduced to less than 0.2% after filling. The linear expansion coefficient of the cured product is also very small, so the internal stress is small and the effect on the bonding strength is small.
(3) There are many varieties of curing agents and modifiers, but they can be used in a reasonable and ingenious manner to make the adhesive have the required processability and functionality.
(4) It has good compatibility and reactivity with a variety of organic and inorganic substances, and is easy to be modified by polymerization, blending, crosslinking, filling, etc. to improve the performance of the glue.
Three disadvantages of epoxy glue:
(1) When it is not toughened, the cured product is generally brittle, and has poor peel resistance, crack resistance and impact resistance.
(2) The adhesion to materials with low polarity (such as polyethylene, polypropylene, fluoroplastics, etc.) is small, and a treatment agent must be used for surface activation treatment, which increases production costs.
(3) Individual diluents and curing agents for epoxy resin glue have varying degrees of toxicity or pungent odor.