Polyvinyl chloride (PVC) is the initiator of peroxides and azo compounds in vinyl chloride monomer (VCM). And it's also a polymer that formed under the action of light and heat according to the mechanism of free radical polymerization.

Toluene diisocyanate has two isomers: 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (TDI).

Polyether polyol (polyether for short) is prepared by adding polymerization reaction of starting agent (compound containing active hydrogen group) with ethylene oxide (EO), propylene oxide (PO), butane oxide (BO) and so on in the presence of catalyst.

Acetonitrile, also known as methyl cyanogen, is a colorless liquid with extremely volatile characteristics. Acetonitrile has a special smell which is similar to ether.