Insight into the Intermolecular Interaction and Free Radical Polymerizability of Methacrylates in Supercritical Carbon Dioxide
Rui-Qing Li,
Ming-Xi Wang,
Qi-Yu Zhang,
Jian-Gang Chen,
Kuan Wang,
Xiao-Yong Zhang,
Shukun Shen,
Zhao-Tie Liu,
Zhong-Wen Liu,
Jinqiang Jiang
Affiliations
Rui-Qing Li
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education and School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
Ming-Xi Wang
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education and School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
Qi-Yu Zhang
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education and School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
Jian-Gang Chen
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education and School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
Kuan Wang
College of Chemistry and Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
Xiao-Yong Zhang
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education and School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
Shukun Shen
School of Materials Science & Engineering, Shaanxi Normal University, Xi’an 710119, China
Zhao-Tie Liu
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education and School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
Zhong-Wen Liu
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education and School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
Jinqiang Jiang
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education and School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
High pressure in situ Fourier transfer infrared/near infrared technology (HP FTIR/NIR) along with theoretical calculation of density functional theory (DFT) method was employed. The solvation behaviors and the free radical homopolymerization of methyl methacrylate (MMA), methacrylate acid (MAA), trifluoromethyl methacrylate (MTFMA) and trifluoromethyl methacrylate acid (TFMAA) in scCO2 were systematically investigated. Interestingly, the previously proposed mechanism of intermolecular-interaction dynamically-induced solvation effect (IDISE) of monomer in scCO2 is expected to be well verified/corroborated in view that the predicted solubility order of the monomers in scCO2 via DFT calculation is ideally consistent with that observed via HP FTIR/NIR. It is shown that MMA and MAA can be easily polymerized, while the free radical polymerizability of MTFMA is considerably poor and TFMAA cannot be polymerized via the free radical initiators. The α trifluoromethyl group (−CF3) may effectively enhance the intermolecular hydrogen bonding and restrain the diffusion of the monomer in scCO2. More importantly, the strong electron-withdrawing inductive effect of −CF3 to C=C may distinctly decrease the atomic charge of the carbon atom in the methylene (=CH2). These two factors are believed to be predominantly responsible for the significant decline of the free radical polymerizability of MTFMA and the other alkyl 2-trifluoromethacrylates in scCO2.
