TY  - JOUR
A1  - Matic, Aleksandar
A1  - Schlaad, Helmut
T1  - Thiol-ene photofunctionalization of 1,4-polymyrcene
JF  - Polymer international
N2  - 1,4-Polymyrcene was synthesized by anionic polymerization of -myrcene and was subjected to photochemical functionalization with various thiols (i.e. methyl thioglycolate, methyl 3-mercaptopropionate, butyl 3-mercaptopropionate, ethyl 2-mercaptopropionate and 2-methyl-2-propanethiol) using benzophenone/UV light as the radical source. The yield of thiol addition to the trisubstituted double bonds of 1,4-polymyrcene decreased in the order 1 degrees thiol (ca 95%) > 2 degrees thiol (ca 80%) > 3 degrees thiol (<5%), due to the reversibility of the thiol-ene reaction. Remarkably, thiol addition to the side-chain double bonds was 8 - 10 times (1 degrees thiol) or 24 times (2 degrees thiol) faster than to the main-chain double bonds, which can be explained by the different accessibility of the double bonds and steric hindrance. Despite the use of a 10-fold excess of thiol with respect to myrcene units, the thiol-ene addition was accompanied by chain coupling reactions, which in the extreme case of 3 degrees thiol (or in the absence of thiol) resulted in the formation of insoluble crosslinked material. As an example, a methyl-thioglycolate-functionalized 1,4-polymyrcene was saponified/crosslinked to give submicron polyelectrolyte particles in dilute alkaline solution. (c) 2018 Society of Chemical Industry
KW  - polymyrcene
KW  - thiol-ene
KW  - photochemistry
KW  - regioselectivity
Y1  - 2018
U6  - https://doi.org/10.1002/pi.5534
SN  - 0959-8103
SN  - 1097-0126
VL  - 67
IS  - 5
SP  - 500
EP  - 505
PB  - Wiley
CY  - Hoboken
ER  -