Low temperature modification of polymers by triazolinediones. Electrophilic substitution of poly(oxy‐2,6‐dimethyl‐1,4‐phenylene)

Poly(oxy‐2,6‐dimethyl‐1,4‐phenylene) (PPE, 8) is reacted with substituted 1,2,4‐triazoline‐3,5‐diones 1 to give the partially substituted poly[oxy‐2,6‐dimethyl‐3‐(1,2,4‐triazoline‐3,5‐dione‐1‐yl)‐1,4‐phenylene]9. The reaction occurs via electrophilic substitution of the electron‐rich PPE with the highly electron deficient triazolinediones 1. For low degrees of substitution, the reaction readily occurs at room temperature. The inherent viscosity decreases with increasing substitution. The results are compared to similarly substituted polybutadiene. The glass transition temperature of the substituted PPE's decreases with the content of triazoline groups, a result which is interpreted by a distortion of the packing in glassy PPE.