Health & Environmental Research Online (HERO)


Print Feedback Export to File
6613185 
Journal Article 
beta-Myrcene/isobornyl methacrylate SG1 nitroxide-mediated controlled radical polymerization: synthesis and characterization of gradient, diblock and triblock copolymers 
Metafiot, A; Gagnon, L; Pruvost, S; Hubert, P; Gerard, JF; Defoort, B; Maric, M; , 
2019 
1 
RSC Advances
EISSN: 2046-2069 
ROYAL SOC CHEMISTRY 
CAMBRIDGE 
9 
6 
3377-3395 
English 
35518984 
WOS:000457880900052 
beta-Myrcene (My), a natural 1,3-diene, and isobornyl methacrylate (IBOMA), from partially bio-based raw materials sources, were copolymerized by nitroxide-mediated polymerization (NMP) in bulk using the SG1-based BlocBuilder (TM) alkoxyamine functionalized with an N-succinimidyl ester group, NHS-BlocBuilder, at T = 100 degrees C with initial IBOMA molar feed compositions f(IBOMA,0) = 0.10-0.90. Copolymer reactivity ratios were r(My) = 1.90-2.16 and r(IBOMA) = 0.02-0.07 using Fineman-Ross, Kelen-Tudos and non-linear least-squares fitting to the Mayo-Lewis terminal model and indicated the possibility of gradient My/IBOMA copolymers. A linear increase in molecular weight versus conversion and a low dispersity ((D) over bar <= 1.41) were exhibited by My/IBOMA copolymerization with f(IBOMA,0) <= 0.80. My-rich and IBOMA-rich copolymers were shown to have a high degree of chain-end fidelity by performing subsequent chain-extensions with IBOMA and/or My, and by P-31 NMR analysis. The preparation by NMP of My/IBOMA thermoplastic elastomers (TPEs), mostly bio-sourced, was then attempted. IBOMA-My-IBOMA triblock copolymers containing a minor fraction of My or styrene (S) units in the outer hard segments (M-n = 51-95 kg mol(-1), (D) over bar = 1.91-2.23 and F-IBOMA = 0.28-0.36) were synthesized using SG1-terminated poly(ethylene-stat-butylene) dialkoxyamine. The micro-phase separation was suggested by the detection of two distinct T(g)s at about -60 degrees C and +180 degrees C and confirmed by atomic force microscopy (AFM). A plastic stress-strain behavior (stress at break sigma(B) = 3.90 +/- 0.22 MPa, elongation at break epsilon(B) = 490 +/- 31%) associated to an upper service temperature of about 140 degrees C were also highlighted for these triblock polymers.