Polyurethane elastomer is a high-performance elastomer with the characteristics of abrasion resistance, cutting resistance, tear resistance, high load-bearing capacity, transparent or translucent, ozone resistance, potting, pouring, and a wide range of hardness. It is widely used in transportation, sports, medical, electronic equipment, military aerospace, machinery manufacturing and other industries.

With the growing market demand for polyurethane elastomer, some common problems in the production process have attracted the attention of producers.

Here are some common problems and solutations to share with you:

1. The viscosity of the prepolymer needs to be reduced:

(1) Optimize the synthesis temperature of the prepolymer  

(2) Polyols are added to isocyanates

(3) Increase stirring

(4) Control the reaction speed to a slower degree

(5) Use the suitable catalyst

(6) Strictly control the moisture content in the raw materials, and the moisture content should be less than 0.05%   

(7) The preparation of prepolymers should be carried out under acidic conditions.

2. The problem of yellowing

(1) Add antioxidants or UV stabilizers

(2) Use aliphatic isocyanates

3. NCO is lower than the theoretical value:

(1) Water enters the reaction system

(2) The proportion is incorrect

(3) There is a loss of isocyanate

(4) Side reactions caused by alkalinity

4.NCO is higher than the theoretical value

(1) The reaction time is too short

(2) The amount of catalyst is insufficient or the catalyst is inappropriate

(3) The reaction temperature is too low

(4) The proportion is incorrect

 5. Causes of bubbles

(1) Water enters the reaction system

(2) Incomplete degassing

(3) Mixing and stirring is not suitable

(4) Bubbles are caught in the pouring process