Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Feb 11;6(7):4939-4949.
doi: 10.1021/acsomega.0c05992. eCollection 2021 Feb 23.

Polymerization of Biobased Farnesene in Miniemulsions by Nitroxide-Mediated Polymerization

Sharmaine B Luk  1 , Milan Maríc  1
Affiliations

Polymerization of Biobased Farnesene in Miniemulsions by Nitroxide-Mediated Polymerization

Sharmaine B Luk et al. ACS Omega. .

Abstract

Biobased farnesene (Far) was polymerized by nitroxide-mediated polymerization in miniemulsions using two different alkoxyamine initiators, the SG1-based and succinimidyl-modified BlocBuilder (NHS-BB) and Dispolreg 007 (D7). Stable emulsions were observed after 30 h of reaction at 90 °C, where NHS-BB-initiated systems resulted in smaller particles (∼300 nm) than using D7 (∼400 nm). Successful chain extension of the poly(Far) macroinitiators (24,500-39,700 g mol-1) with styrene were achieved using 15 wt % surfactant relative to monomer concentration. Compartmentalization effects were not observed in these emulsions as the polymerization rate was still much slower compared to the bulk, even though Z-averaged particle sizes were around 300-400 nm. Finally, all biobased diblock copolymers were synthesized by chain-extending poly(Far) macroinitiators with isobornyl methacrylate (iBOMA), where the D7 initiator showed more effective chain extension (less unreacted macroinitiator) than NHS-BB.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing financial interest.

Figures

Scheme 1
Scheme 1. Chemical Structures of Petroleum-Derived Dienes, Butadiene, and Isoprene, and Biosourced Dienes, Myrcene and Farnesene
Figure 1
Figure 1
Linearized conversion vs time plot for the homopolymerization of farnesene in miniemulsions using D7 at 90 °C in 20 wt % monomer with 5 and 15 wt % surfactant and a Mn,target = 50,000 g mol–1.
Figure 2
Figure 2
(a) Molecular weight and (b) dispersity vs conversion plots for the homopolymerization of farnesene in miniemulsions using D7 at 90 °C in 20 wt % monomer with 5 and 15 wt % surfactant and Mn,target = 50,000 g mol–1.
Figure 3
Figure 3
MWD of poly(Far-b-St) after 120 min of chain extension of poly(Far) made with 15 wt % surfactant and Mn,target = 50,000 g mol–1.
Figure 4
Figure 4
Linearized conversion vs time plot for the homopolymerization of farnesene in miniemulsions using D7 at 90 °C in 20 wt % monomer with 15 wt % surfactant and Mn,target = 30,000 and 50,000 g mol–1.
Figure 5
Figure 5
(a) Molecular weight and (b) dispersity vs conversion plots for the homopolymerization of farnesene in miniemulsions using D7 at 90 °C in 20 wt % monomer with 15 wt % surfactant and Mn,target = 30,000 and 50,000 g mol–1. The solid line in (a) represents the theoretical Mn for Mn,target = 50,000 g mol–1, and the dashed line represents the theoretical Mn for Mn,target = 30,000 g mol–1.
Figure 6
Figure 6
MWD of poly(Far-b-St) after 120 min of chain extension of poly(Far) made with 15 wt % surfactant and Mn,target = 30,000 g mol–1.
Figure 7
Figure 7
Z-averaged particle size of miniemulsions for homopolymerizations of farnesene in 5 and 15 wt % surfactant using D7 and NHS-BB initiators at 90 °C with a Mn,target = 50,000 g mol–1.
Scheme 2
Scheme 2. Diagram of Conventional Emulsion Polymerization (Left) vs Miniemulsion Polymerization (Right)
Droplets are stabilized by surfactants, and the red arrows in the right show mass transfer of monomer from monomer reservoir into the aqueous phase and then into the micelles for polymerization to occur. Initiator is represented by I• either in the aqueous or oil phase.
Figure 8
Figure 8
Volume-averaged particle size from DLS for homopolymerizations of Far in miniemulsions in 20 wt % monomer using D7 and NHS-BB initiators at 120 °C.
Figure 9
Figure 9
Z-averaged particle size of miniemulsions for homopolymerizations of farnesene in 15 wt % surfactant using D7 at 90 °C with Mn,target = 30,000 and 50,000 g mol–1.
Figure 10
Figure 10
Molecular weight distributions of homopolymerizations of Far in miniemulsions and Mn,target of 50,000 g mol–1 using D7 and (a) 5 wt % and (b) 15 wt % surfactant, and using NHS-BB and (c) 5 wt % and (d) 15 wt % surfactant.
Figure 11
Figure 11
Molecular weight distributions of homopolymerizations of Far in the miniemulsion with 20 wt % monomer loading and Mn,target of 30,000 g mol–1 using D7 and 15 wt % surfactant.
Figure 12
Figure 12
MWD of poly(Far-b-iBOMA-ran-Far) after 90 min of chain extension of poly(Far) made with NHS-BB, 15 wt % surfactant, and Mn,target = 50,000 g mol–1.
Figure 13
Figure 13
MWD of poly(Far-b-iBOMA) after 90 min of chain extension of poly(Far) made with D7, 15 wt % surfactant, and Mn,target = 50,000 g mol–1.
See this image and copyright information in PMC

References

    1. Morton M.; McGrath J. E.; Juliano P. C. Structure-property relationships for styrene-diene thermoplastic elastomers. J. Polym. Sci., Part C: Polym. Symp. 1969, 26, 99–115. 10.1002/polc.5070260107. - DOI
    1. Drobny J. G.15-Applications of Thermoplastic Elastomers. In Handbook of Thermoplastic Elastomers; Drobny J. G., Ed.; William Andrew Publishing: Norwich, NY, 2007; pp 281–315.
    1. Wang S.; Wang Q.; Wu X.; Zhang Y. Asphalt modified by thermoplastic elastomer based on recycled rubber. Constr. Build. Mater. 2015, 93, 678–684. 10.1016/j.conbuildmat.2015.06.047. - DOI
    1. White W. C. Butadiene production process overview. Chem.-Biol. Interact. 2007, 166, 10–14. 10.1016/j.cbi.2007.01.009. - DOI - PubMed
    1. Custro S.; Zazzetta A.. Styrene-isoprene block copolymers. U.S. Patent 5,284,915 A, 1994.