Polyurethane has two main raw materials, isocyanate (including TDI, MDI, PIDI, HDI, etc.) and polyether polyol. Among them, isocyanate is relatively toxic, especially TDI is recognized as toxic, carcinogenic and irritating.
In addition, other ingredients used in the foaming process mainly include:
1. Catalyst, mainly amine catalyst and tin catalyst. Amine catalysts are toxic and irritating to the respiratory tract, mucous membrane and eyes, as the leader of the East Polar Cult Zushenta said upstairs. Tin catalysts also have certain toxicity. Basically, the VOC of the foam generated by the combination of this catalyst, that is, volatile organic compounds, will be higher
2. Surfactants, mainly silicone oil, are non-toxic, but harmful to the environment.
3. Foaming agents, mainly HFC, that is, Freon, are used more often and are non-toxic and harmful.
As a new type of thermal insulation material, hard foam polyurethane has the advantages of low thermal conductivity, good dimensional stability, low water absorption, firm and seamless bonding with the base layer, and good integrity. In particular, the on-site spraying of hard foam polyurethane can meet the characteristics of low temperature, high humidity, and high air tightness requirements of the cold storage, and it is easy to construct, with good vapor and moisture isolation effect, which can achieve better energy conservation goals, It is the first choice of energy-saving materials for cold storage insulation engineering at present.
Source: Zhihu
