New process for synthesizing fluorinated polymers in supercritical carbon dioxide

作者：Liu Zhao Tie^*; Chen Jian Gang; Liu Zhong Wen; Lu Jian

来源：Macromolecules, 2008, 41(19): 6987-6992.

DOI：10.1021/ma800193v

The typical polymerization process in supercritical fluids (SCFs) was improved through modifying the reaction system and designing and using sampling tubes. The efficacy of the newly developed procedure was demonstrated by the free radical homopolymerization of 2,2,2-trifluoroethyl methacrylate (TFEMA) and coplymerization of TFEMA and N-vinylpyrrolidone (NVP) in supercritical carbon dioxide (scCO(2)). Results indicate that the newly developed procedure has the characteristics of minimum loss of reactants and polymerization starting at the desired temperature and pressure. Furthermore, the polymerization process can be well tracked by analyzing the reaction mixtures online sampled from the reactor at certain reaction times by FT-IR, (1)H NMR, and GPC. The reaction time and the product properties can be optimized based on the tracking results. For the first time, block copolymers by free radical polymerization in scCO(2) was successfully synthesized by sequential addition of TFEMA and methyl methacrylate (MMA) into the reactor at different reaction stages. The synthesized polymers were characterized by FT-IR, (1)H NMR, (13)C NMR, GPC, TGA, and DSC, respectively. It was proved that the losing of monomer, pollution to the environment, and distribution of the molecular weight of the synthesized polymers decreased while the yield of product, the reproducibility, and the controllability of polymerization increased after improvement of the polymerization process.

• 出版日期2008-10-14
• 单位陕西师范大学