Molecular Structure of Styrene-Butadiene Copolymers

Nielsen, Lawrence E.; Buchdahl, Rolf; Claver, George C.

doi:10.1021/ie50494a025

Cited by 18 publications

(3 citation statements)

References 6 publications

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“…This has an equivalent mechanical model of a spring of compliance GI in series with a retarded spring of compliance G and retardation time r . The condition analogous to (6) for negative stress in this material is Below a critical value of p7 the stress remains positive, while above it becomes zero after an initial transient analogous with that in (5) ; so that as p7 rises it again becomes possible to follow a number of cycles within the transient time before the stress becomes negative, and a non-elliptical trace should arise in our type of experiment only in a range just above the condition (8). For amorphous material we may put G1 < G and G is large (see fig.…”

Section: (1)mentioning

confidence: 87%

The transitions of polyethylene terephthalate

Thompson¹,

Woods²

1956

Trans. Faraday Soc.

153

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The dynamic tensile moduli and mechanical loss factors of polyethylene terephthalate filaments in different states of orientation and crystallinity have been measured between -80" C and + 180" C , and from 10-3 c/s to 104 c/s. It is shown that at 1 c/s the main transition temperature rises from 80" C to 125" C, with increasing crystallinity while its apparent activation energy meanwhile falls from 182 kcal/mole to 97 kcal/mole. There is a second transition at about -40" C with an apparent activation energy of 17 kcal/mole, which is less affected by crystallinity. Possible molecular interpretations of these results are considered.Three main types of study of glass transitions in high polymers 1 have been made : theoretical investigations into their relation with thermodynamic secondorder transitions on the one hand, and relaxation transitions on the other; 2 detailed measurements of the transitions in a single polymer,29 3 and comparative studies of transitions in related polymers. As examples of this last class we may 1383

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Section: (1)mentioning

confidence: 87%

The transitions of polyethylene terephthalate

Thompson¹,

Woods²

1956

Trans. Faraday Soc.

153

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“…An apparatus for determining dynamic shear properties by coupling elastomers in shear to the prongs of tuning forks has been described (72). The dynamic shear moduli and damping of a series of butadiene-styrene copolymers at different temperatures have been determined by a new design of recording torsion pendulum (113). Experimental evidence indicates that if it were possible to synthesize a polymerized butadiene elastomer containing no cross linking and no crystalline component, the product should be rubberlike even at -140°C.…”

Section: Physical Propertiesmentioning

confidence: 99%

Elastomers

Fisher¹

1951

Ind. Eng. Chem.

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“…Phenyl functionalized butadienes, which can be polymerized through ionic, emulsion, or Ziegler–Natta type methods, allow for synthesis of ES copolymers with greater microstructural control by eliminating statistical comonomer distributions compared to SBR. − However, utilization of these polymerization methods to synthesize ES copolymers also presents challenges. Namely, this polymerization method often results in 1,2 or 3,4 addition rather than 1,4 (especially with 1-phenylbutadiene), which limits the full scope of microstructural possibilities. − ,,,− Furthermore, phenyl functionalized butadiene polymers obtained that contain 3,4 addition can undergo intramolecular cyclization. ,,, High content of 1,4 cis addition (>99%) of 2-phenylbutadiene has been obtained with emulsion polymerization and with certain Ziegler–Natta catalysts; however, material properties of the hydrogenated polymer were not investigated. , …”

Section: Introductionmentioning

confidence: 99%

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

Kieber

Neary

Kennemur

2018

Ind. Eng. Chem. Res.

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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.

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Molecular Structure of Styrene-Butadiene Copolymers

Cited by 18 publications

References 6 publications

The transitions of polyethylene terephthalate

The transitions of polyethylene terephthalate

Elastomers

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

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