Tensile strength elevation of brittle polymers by entanglements

Turner, D. T.

doi:10.1016/0032-3861(82)90106-9

Cited by 38 publications

(7 citation statements)

References 23 publications

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“…It was observed that each mechanical property decreased with a decrease in M n (in other words, an increase in M e * ). This tendency of the mechanical strength (breaking stress) to depend on M n agrees with the results of Flory . In addition, each mechanical property decreased dramatically at around a certain M n .…”

Section: Resultsmentioning

confidence: 99%

Variation of periodic crazing based on polymer blends of an ultra‐high and a low molecular weight poly(methyl methacrylate)

Naito

Takeno

Morifuji

et al. 2016

J of Applied Polymer Sci

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Periodic crazes are caused in a polymer film by the unique mechanical method using bending. Generation of a craze depends on entanglements of the molecular chains of a polymer. Therefore, control of composite morphology of periodic crazes was attempted by varying the entanglements of molecular chains. An effective entanglement network became sparse by polymer blends of an ultra-high molecular weight polymethylmethacrylate (PMMA) and a low molecular weight PMMA. Consequently, the composite morphology of periodic crazes caused in the blend film varied. In other words, the periodic craze can be used for the evaluation of the effective entanglements. In addition, it was figured out that PMMA of which the number-average molecular weight (M n ) is less than twice of the effective entanglement molecular weight (M e *) works as a plasticizer in the blend film. And also, it was revealed that the mechanical properties of the blend film decreased dramatically at M n Լ 6M e *. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44332.

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Section: Resultsmentioning

confidence: 99%

Variation of periodic crazing based on polymer blends of an ultra‐high and a low molecular weight poly(methyl methacrylate)

Naito

Takeno

Morifuji

et al. 2016

J of Applied Polymer Sci

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“…Referring to the work of Taylor and Darin [15] and Bueche [16] some authors [17,18] recently proposed an apparently morphological entanglement network model ( fig. 1).…”

Section: Sample Strength Correlated With Number Of Load Bearing Unitsmentioning

confidence: 97%

Stress-transmission through chain molecules

Kausch

1985

Colloid & Polymer Sci

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“…The loss in weight during exposure to ultraviolet light is also consistent with scission of the polymer to produce volatile products. The sudden loss of tensile strength is typical for scission in an amorphous polymer which derives its cohesive Many studies have demonstrated that ultimate strength properties of a polymer are relatively unaffected by a reduction of molecular weight until chains have become so short that they can no longer effectively entangle with each other and provide cohesive strength to the film [30][31][32]. Finally, the increased hardness and loss of ductility resulting from ultraviolet light exposure probably arise from the increased attraction between the polymer chains as they incorporate polar groups during oxidative degradation.…”

Section: Discussionmentioning

confidence: 99%

The natural and accelerated aging of an acrylic artists' medium

Whitmore¹,

Colaluca²

1995

Studies in Conservation

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Changes in appearance and in the chemical and mechanical properties of films of Liquitex acrylic gloss medium, a commercial artists' medium based on an acrylic polymer dispersion, have been studied during natural aging in the dark and in accelerated thermal and light exposure tests. In dark storage at room temperature and humidity, the films acquire a haze and slight yellow discoloration in a few weeks, while the tensile properties stabilize only after film formation has progressed for about 50 days. Crosslinking seems to occur slowly at room temperature, causing the film to become only partially soluble in benzene and butanone, although the extent of this crosslinking does not seem to cause difficulty in film removal even after extended heat aging. The resistance of this polymer material to photochemical degradation by near-ultraviolet light is very high. Exposure of these films to near-ultraviolet light causes very slow scission and oxidation of the polymer, producing a gradual increase in solubility and hardness; severely degraded films suffer a sudden loss of tensile strength.

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Tensile strength elevation of brittle polymers by entanglements

Cited by 38 publications

References 23 publications

Variation of periodic crazing based on polymer blends of an ultra‐high and a low molecular weight poly(methyl methacrylate)

Variation of periodic crazing based on polymer blends of an ultra‐high and a low molecular weight poly(methyl methacrylate)

Stress-transmission through chain molecules

The natural and accelerated aging of an acrylic artists' medium

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