Isospecific Polymerization of 1‑Phenyl-1,3-butadiene and Its Copolymerization with Terpene-Derived Monomers

TL;DR

This paper explores the polymerization of a biobased monomer and its copolymerization with terpenes to create sustainable materials with tunable properties.

Contribution

The study introduces a new method for stereospecific polymerization of 1-phenyl-1,3-butadiene and its copolymerization with terpene-derived monomers.

Findings

Highly isotactic and 3,4-regioselective polymerization of 1PB was achieved with a titanium catalyst.

Hydrogenation significantly lowered the glass transition temperature of the polymer.

Copolymers with terpenes showed tunable thermal properties and partial cross-linking.

Abstract

The transition from fossil-based materials to biobased
alternatives
has become a critical research focus, particularly in the polymer
sector, due to environmental concerns such as rising CO2 levels and microplastic pollution. This work explores the stereospecific
polymerization of 1-phenyl-1,3-butadiene (1PB), a bioderived monomer
from cinnamaldehyde, using a titanium [OSSO]-type catalyst activated
by MAO. The polymerization exhibited high 3,4-regioselectivity and
isotacticity (mmmm > 99%) with a maximum yield
of
65% at 80 °C. Post-polymerization hydrogenation reduced the glass
transition temperature (T
g) from ≈80
°C to ≈17 °C, highlighting the impact of double bond
removal on polymer flexibility. Additionally, copolymerizations of
1PB with natural terpenes β-ocimene (O) and S-4-isopropenyl-1-vinyl-1-cyclohexene (IVC) were conducted, yielding
multiblock copolymers PPBO and PPBI, respectively, with tunable thermal
properties. These copolymers showed partial cross-linking reactions
and consequent presence of two glass transition temperatures (T
g). For PPBO copolymers, the low T
g values tended to significantly decrease as the terpene
content increased, whereas for the PPBI copolymers, the low T
g values showed minimal changes due to the similar T
g of their homopolymers. These findings demonstrate
the potential of renewable monomers for producing sustainable polymers.

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