can't read?
4,4'-Azobis(4-cyanovaleric acid) is used as a free radical imitator in polymer synthesis such as polyvinyl chloride, polyacrylonitrile, polyvinyl alcohol and synthetic fibers.
A 3516 (OTTO) 4,4′-Azobis(4-cyanovaleric acid) ≥98% Cas 2638-94-0 - used as a blowing agent for plastics and elastomers.