(Meth)acrylic monomers with heteroatom-containing ester side chains: a systematic PLP-SEC and polymerization study

• Published in: Polymer chemistry Vol. 5; no. 3; pp. 862 - 873
• Main Authors: Haehnel, Alexander P., Stach, Marek, Chovancová, Anna, Rueb, Jannick M., Delaittre, Guillaume, Misske, Andrea M., Lacík, Igor, Barner-Kowollik, Christopher
• Format: Journal Article
• Language: English
• Published: 07.02.2014
• Subjects: Acrylates
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/C3PY00948C

The Arrhenius parameters of the propagation rate coefficient for two hetero-atom containing (meth)-acrylates (studied as 1 M solution in N,N-dimethylacetamide (DMAc)) are determined viathe pulsed laser polymerization - size-exclusion chromatography (PLP-SEC) method. Absolute molar mass determination is achieved via SEC coupled to on-line multi-angle laser light scattering (MALLS). The data obtained for hydroxypropylcarbamate acrylate (HPCA, A= 3.97 (-1.44 to 1.63) 10 super(6) L mol super(-1) s super(-1) and E sub(a) = 14.3 (-1.38 to 5.13) kJ mol super(-1)) are critically compared with the literature known data sets of two structural derivatives, i.e., 2-(phenylcarbamoyloxy)isopropyl acrylate (PhCPA) and 2-(hexylcarbamoyloxy)isopropyl acrylate (HCPA), indicating an increase in the propagation rate coefficient with increasing ester side chain length. Ureidoethyl methacrylate (UMA, A= 2.08 (-0.45 to 0.91) 10 super(6) L mol super(-1) s super(-1) and E sub(a) = 19.9 (-0.89 to 0.91) kJ mol super(-1)) represents the first hetero-atom containing methacrylate to be studied via PLP-SEC, evidencing a significantly higher propagation rate coefficient compared to earlier investigated methacrylate-type monomers. Furthermore, the free-radical polymerization behavior of HPCA and UMA is studied via in situ super(1)H-NMR experiments at elevated temperatures allowing for an estimation of average termination rate coefficients (at low conversion) in conjunction with the determined k sub(p) data. Furthermore, the polymerization of UMA was successfully controlled by reversible addition-fragmentation chain transfer (RAFT) polymerization as evidenced by the linear evolution of the number-average molar mass, M sub(n), with conversion (3000 g mol super(-1) less than or equal to M sub(n) less than or equal to 23 000 g mol super(-1), 1.15 less than or equal to D less than or equal to 1.3) as well as by nitroxide-mediated polymerization (NMP), as demonstrated by the linear evolution of M sub(n) with conversion (4000 g mol super(-1) less than or equal to M sub(n) less than or equal to 40 000 g mol super(-1), 1.3 less than or equal to D less than or equal to 1.4). In addition, HPCA polymerization was successfully controlled by the RAFT process, as evidenced by the linear evolution of M sub(n) with conversion (2000 g mol super(-1) less than or equal to M sub(n) less than or equal to 21 000 g mol super(-1), 1.2 less than or equal to D less than or equal to 1.4) and successful chain extension experiments. Finally, the NMP of HPCA exhibited uniform shifts of the molar mass distributions in the range of 5000 g mol super(-1) less than or equal to M sub(n) less than or equal to 70 000 g mol super(-1) and successful chain extension experiments.