EFFECT OF ALKYL SUBSTITUENTS ON THE THERMAL-DEGRADATION OF POLY(ALKYLMETHACRYLATE) - A MOLECULAR-ORBITAL STUDY USING THE ASED-MO METHOD

The effect of alkyl substituents on the stability and degradation prod ucts of alkyl methacrylate polymers has been explained in terms of ASE D-MO theory. The calculations explained that the formation of methyl, ethyl, n-propyl, and n-butyl methacrylate monomers as the principal pr oducts during the thermal degradation of their polymers is due to thei r high stabilities, which probably correspond to the high energy separ ation between HOMO-LUMO levels. However, the t-butyl methacrylate mono mer shows the smallest energy separation, which increases its tendency towards the ester decomposition mechanism during the thermal degradat ion of poly(t-butyl methacrylate).