Novel Copolymers of Styrene. 4. Halogen Ring-Substituted Butyl 2-Cyano-3-Phenyl-2-Propenoates

Abstract

Novel trisubstituted ethylenes, halogen ring-substituted butyl 2-cyano-3-phenyl-2-propenoates, RPhCH ˭ C(CN)CO₂C₄H₉ (where R 2-Br, 3-Br, 4-Br, 2-Cl, 3-Cl, 4-Cl, 2-F, 3-F, 4-F) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and butyl cyanoacetate, and characterized by CHN analysis, IR, ¹H and ¹³C-NMR. All the ethylenes were copolymerized with styrene (M₁) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, ¹H and ¹³C‒NMR. The order of relative reactivity (1/r₁) for the monomers is 3-F (22.97) > 3-Br (6.05) > 2-Cl (4.32) > 4-F (3.19) > 4-Br (2.47) > 4-Cl (1.92) > 2-F (1.74) > 3-Cl (1.10) > 2-Br (1.07). Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500°C range with residue (2.3–5.9% wt.), which then decomposed in the 500–800°C range.

Keywords:

• Trisubstituted ethylenes
• radical copolymerization
• styrene copolymers

Funding

We are grateful to acknowledge that the project was partly supported by the Coatings Industry Education Fund (CIEF), Chicago Society of Coating Technology (CSCT) and Office of Sponsored Programs and Research of DePaul University. Youya Gao was partially supported by the CIEF and CSCT funds.