Confined polymerizability

METHYL-l-PHENYL-ETHYLENE (98-83-9) C9H10 Flammable liquid. Forms explosive mixture with air [explosion limits in air (vol %) 0.9 to 6.1 flash point 129°F/54°C autoignition temp 1066°F/574°C Fire Rating 2], Easily polymerizable. Unless inhibited, forms unstable peroxides. Reacts with heat and/or lack of appropriate inhibitor concentration. Reacts with catalysts for vinyl or ionic polymerization, such as aluminum, iron chloride or 2,5-dimethyl-2,5-di(ieri-butylperoxy)hexane. Violent reaction with strong oxidizers, butyl lithium, oleum, xenon tetrafluoride. Incon atible with acids. The uninhibited monomer vapor may block vents and confined spaces by, forming a solid polymer material. Attacks aluminum and copper. On small fires, use dry chemical powder (such as Purple-K-Powder), foam, or CO2 extinguishers. 

The mechanism of photodegradation of certain hydroxyphenyl benzotriazole based ultraviolet absorbers has been investigated and a new polymerizable ultraviolet absorber in this group has been synthesized. The photoreactivity is entirely confined at the surface of polymethylmethacrylate films containing the ultraviolet absorbers as pendant groups. A mechanism involving sensitized photooxidation has been proposed to interpret the data. 

---