Photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization of acrylonitrile in miniemulsion

Abstract

Photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization of acrylonitrile (AN) in miniemulsion was reported. PET-RAFT polymerization of acrylonitrile (AN) was successfully accomplished with 4-cyanopentanoic acid dithiobenzoate (CPADB) as chain transfer agent (CTA), sodium dodecyl sulfate (SDS) as emulsifier, hexadecane (HD) as co-stabilizer and TiO₂ as photocatalyst at 25 °C. The linear first-order kinetic plots were observed in miniemulsion with different amounts of SDS. Excellent temporal control was demonstrated by switching between ON/OFF states multiple times, and the prepared PAN macro-CTA was used successfully to perform the chain extension experiments, indicating high retention of chain end functionality. Furthermore, the obtained PAN was amidoximated with NH₂OH·HCl. The Cd²⁺ was extracted with amidoxime (–C(NH₂)=NOH) from aqueous solutions. The maximum adsorption of 98.6% Cd²⁺ with 400 mg of the adsorbent was observed at pH 6.0 and an initial Cd²⁺concentration of 4 mmol/L.

Keywords:

• PET-RAFT
• miniemulsion polymerization
• living radical polymerization
• adsorption
• Cd²⁺

Acknowledgments

The authors are grateful for the financial support by Key Research and Development Project of Hainan Province (ZDYF2016020), and Natural Science Foundation of China (21762016).