Viscoelastic, Mechanical, and Glasstomeric Properties of Precision Polyolefins Containing a Phenyl Branch at Every Five Carbons

Abstract

Mechanical and viscoelastic properties of precision polyolefins, poly­(4-phenylcyclopentene) (P4PCP) and its hydrogenated analog (H2-P4PCP) containing atactic phenyl branches at exactly every five carbons along the backbone are explored. Both materials are amorphous with a glass transition temperature of ∼17 ± 3 °C. Rheological investigations determined that P4PCP has an entanglement molar mass (M e = 10.0 kg mol–1) much higher and closer to polystyrene than H2-P4PCP (M e = 3.6 kg mol–1). Both materials have elastomeric and shape memory properties at ambient temperatures, which were further explored through strain hysteresis measurements. H2-P4PCP has an elastic recovery of ∼95% at max strain values up to 500% as determined by uniaxial tensile testing. Time–temperature superposition analysis, Williams–Landel–Ferry constants, and further mechanical analysis are discussed and compared to previously reported ethylene–styrene copolymers of similar phenyl-branch content within the microstructure.

Polypentenamer Renaissance: Challenges and Opportunities

“…P4PCP and H 2 –P4PCP are rubbery amorphous materials with a nearly identical T g (17 ± 2 °C) just below ambient temperature which is a key attribute for sound and vibration dampening materials . Further exploration of the viscoelastic and mechanical properties revealed that both share similar density (ρ 24°C = 1.03 ± 0.01 g cm –3 ), but P4PCP has a much higher entanglement molar mass ( M e = 10.0 kg mol –1 ) versus H 2 –P4PCP (3.6 kg mol –1 ) leading to differing mechanical properties at similar M n . H 2 –P4PCP, which can be likened to an ethylene–styrene (ES) copolymer with exactly 71.4% w/w styrene, is a model material for studying property differences between precise and imprecise microstructure.…”

“…Statistical ES copolymers previously reported display higher values, which vary greatly with only a 4% difference in composition. Values are from ref .…”

Precision Polyelectrolytes with Phenylsulfonic Acid Branches at Every Five Carbons

“…We note that due to the odd integer branch topology, an alternative descriptor is a perfectly alternating trimethylene‐styrene copolymer. This material, which we term here as p 5Ph, has a reduced T g (17 ± 2 °C) and entanglement molar mass ( M e ) of 3.6 kg mol −1 when compared to PS (13 kg mol −1 ) due to the trimethylene segment . In a recent study, we reported interesting “glasstomeric” behavior of p 5Ph, which has an elongation at break >1000% and has an elastic recovery of ≈95% from 500% strain at a rate of 0.02 s −1 .…”

“…This material, which we term here as p 5Ph, has a reduced T g (17 ± 2 °C) and entanglement molar mass ( M e ) of 3.6 kg mol −1 when compared to PS (13 kg mol −1 ) due to the trimethylene segment . In a recent study, we reported interesting “glasstomeric” behavior of p 5Ph, which has an elongation at break >1000% and has an elastic recovery of ≈95% from 500% strain at a rate of 0.02 s −1 . Given the markedly different properties between PS and p 5Ph, we rationalized that sulfonation of p 5Ph could potentially lead to an analog of PSS with advantageous properties and the potential ability to be thermally processed.…”

Fluorine-Free Precise Polymer Electrolyte for Efficient Proton Transport: Experiments and Simulations

“…The parent poly(4-phenylcyclopentene) (P4PCP) and its hydrogenated analog (p5Ph) are both amorphous, have a low glass transition temperature (T g ≈ 17 °C), and are well entangled at the degree of polymerization (~712) used in this study. [13][14][15][16] We recently investigated p5PhSA neutralized with a variety of metal cations, and found that in the dry state the ions and sulfonate groups strongly nanophase separate from the polymer backbone and self-assemble into percolated ionic aggregates. 17 We thus anticipated that p5PhSA would also nanophase separate into hydrophilic and hydrophobic domains.…”