REACTION MECHANISM OF NAH WITH THE STRUCTURAL UNIT OF BUTYL RUBBER RESEARCH THROUGH THE α-PINENE MODEL COMPOUND METHOD

Abstract

ABSTRACT We substituted the small molecular model compound α-pinene of butyl rubber (IIR) to simulate the reaction between sodium hydride (NaH) and the isoprene structural unit of IIR. Meanwhile, we provided reference data on the reaction mechanism and reaction degree for the modified reaction of IIR with an active carboanion-based center. In this way, possible chemically modified reaction pathways of IIR were studied. 1H nuclear magnetic resonance results showed that α-pinene and the structural unit of IIR have a very high degree of similarity. NaH can not only produce the substitution reaction in the allylic position with α-pinene, but it can also result in the double-bond addition reaction. The degree of substitution reaction was higher than that of the addition reaction. Reaction time, the amount of NaH, and different carboanion acceptors can also greatly affect the degree of the reaction. Fourier transform infrared results indicated that the maleic anhydride experienced a ring-opening reaction rather than the double-bond addition reaction. This means that the generated carboanion primarily attacked the C=O bond on the molecular structure of the maleic anhydride and introduced the polar functional groups and unsaturated double-bond functional groups to the molecular structure of α-pinene.