Toward Functionalized Polyolefins from the Hydrogenation of Isoprene–Glycidyl Methacrylate Copolymers Prepared by Reversible Deactivation Radical Polymerization in Heterogeneous Media

Abstract

Isoprene−glycidyl methacrylate (GMA) copolymers (3%−4% GMA) were prepared by two reversible deactivation radical polymerization (RDRP) techniques (nitroxide-mediated polymerization (NMP) and reversible addition-fragmentation chain transfer polymerization (RAFT)) in one-pot emulsion polymerization as precursors of polar/functional polyolefins obtained after copolymer hydrogenation. The maximum level of hydrogenation obtained using a palladium acetate catalyst was 68% for an NMPsynthesized copolymer; the RAFT copolymers proved more difficult to hydrogenate, apparently because of catalyst deactivation caused by the RAFT agent, reaching 19% and 33% hydrogenation with the Pd acetate catalyst and with a Pd(0) catalyst supported in activated carbon, respectively. The copolymers (before and after hydrogenation) were successfully tested as compatibilizers for 80/ 20 (w/w) Nylon-6−polypropylene (PA6/PP) blends, showing that the NMP copolymers exhibit the best performance, especially after hydrogenation. The copolymers were characterized by hydrogen nuclear magnetic resonance ( 1 H NMR), Fourier transform infrared (FTIR) spectroscopy, size exclusion chromatography (SEC), and differential scanning calorimetry (DSC), and the blends by dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The results indicate that the strategy used to obtain polar/functional polyolefins is promising and should be relatively easy to scale-up, compared to other processes.

Toward Bio‐Sourced Elastomers with Reactive/Polar Groups. Myrcene – Glycidyl Methacrylate Copolymerization: Reactivity Ratios, Properties, and Preliminary RAFT Emulsion Polymerization

“…Sahu et al. [ 21 ] recently reported on a similar effort to generate Myr‐GMA elastomers in emulsion polymerization, but they used a redox initiator and polymerized at 20 °C to minimize the gel formation. Still, they obtained from 5% to 20% of gel content with increasing cross‐linked material content the higher the GMA content (10–100%).…”

“…[ 39 ] The formulations and procedure used in the emulsion polymerizations, including the use of a St seed formed in situ, are based on previous experience of our group with NMP and RAFT emulsion processes, [ 19–21 ] particularly with the emulsion copolymerization of Is and GMA in emulsion via RAFT, recently published. [ 21 ]…”

“…It should be remembered that some of the St-BD elastomers produced in industry via emulsion polymerization at relatively high temperatures (60-80 °C), in the so-called hot process, have a significant gel content. [39] The formulations and procedure used in the emulsion polymerizations, including the use of a St seed formed in situ, are based on previous experience of our group with NMP and RAFT emulsion processes, [19][20][21] particularly with the emulsion copolymerization of Is and GMA in emulsion via RAFT, recently published. [21] Figure 9 shows the evolution of global conversion with time for the polymerizations.…”

“…[39] The formulations and procedure used in the emulsion polymerizations, including the use of a St seed formed in situ, are based on previous experience of our group with NMP and RAFT emulsion processes, [19][20][21] particularly with the emulsion copolymerization of Is and GMA in emulsion via RAFT, recently published. [21] Figure 9 shows the evolution of global conversion with time for the polymerizations. The initial slope indicates a relatively fast reaction rate up to 40-50% conversion, followed by a slower reaction.…”

“…In these polymerizations a technique previously developed in our group was used: this technique, originally developed a few years back, [ 19 ] allowed the obtainment of nitroxide‐controlled polystyrene (PS) and has been successfully replicated for the copolymerization of St with acrylic monomers [ 20 ] and that of Is with GMA. [ 21 ]…”