Crystalline poly(tert‐butyl acrylate)

Crystalline poly(tert‐butyl acrylate) was prepared with lithium dispersions, n‐butyllithium, and lithium plus n‐butyllithium as catalysts. Methyl acrylate, n‐, see‐, and iso‐butyl acrylate gave only amorphous polymer under the conditions that produced crystalline poly(iert‐butyl acrylate). Very pure monomer was necessary for the preparation of crystalline poly(tert‐butyl acrylate) with lithium dispersions. That the poly(tert‐butyl acrylate) was crystalline was shown by x‐ray diffraction, observation with the polarizing microscope (preparation of birefringent spherulites) and the electron microscope, study of infrared absorption, softening point, and density, and finally by preparation of crystalline polymethyl acrylate from crystalline poly(tert‐butyl acrylate) by ester interchange. The nuclear magnetic resonance spectrum of the crystalline poly(tert‐butyl acrylate) showed no evidence of band splitting and the viscosity‐slope constant, k′, was the same for crystallizable and noncrystallizable polymer.