Principle of PU Solid Tire Chemical Reaction
Our pu solid tire adopts bio-based environmental protection polyether polyol and whole water foaming process. Therefore, the pu tire's manufacturing process is more environmentally friendly.
1. Reaction of isocyanates with hydroxyl groups
Isocyanate can react with active hydrogen of hydroxyl containing compounds such as alcohol, polyol, polyether and polyester to form carbamate.
2. Reaction of isocyanate with water
The reaction of isocyanate with water first produces unstable carbamate, which is then decomposed into carbon dioxide and amine.
R—NCO + H2O → R—NHCOOH → R—NH2 + CO2 R—NCO + RNH2 → R—NHCONH—R
3. Reaction of isocyanates with amino groups
The reaction of isocyanate with amine group produces urea.
4. Reaction of isocyanate with urea
The reaction between isocyanate and substituted urea produces biuret, which produces branching or cross-linking.
5. Reaction of isocyanate with carbamate
The reaction activity between isocyanate and carbamate is lower than that of urea. Only at high temperature (120 ~ 1400C) or under the action of selective catalyst, isocyanate and carbamate can have sufficient reaction speed, and urea formate can be formed through polymerization.
6. Crosslinking reaction of isocyanate
In the actual polyurethane preparation process, in order to improve the mechanical properties of products, some small molecular alcohols or amines with more than 2 functionality will be used. We take ternary alcohols as an example to show the crosslinking reaction of NCO, as follows：
