Hole Fraction Dependence on Linear Viscosity of PS, PP and ABS

Dinc, Fatma Sahin

doi:10.3139/217.3101

Cited by 8 publications

(18 citation statements)

References 18 publications

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“…Free volume phenomenon in the polymers, which is defined as the gap or spaces occupied between the chains of polymers, may give the key explanations about some significant physical quantities of the polymers such as mechanical, 27 thermodynamic properties, 28 permeability. 29 Viscosity, 30,31 the ionic conductivity, 32 the dielectric relaxation 33 etc. It is known that there exists an inverse relationship between free volume and mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the relation between free volume and physico-mechanical performance in rigid polyurethane foam containing turkey feather fibers: Part 2

Soykan

Khaleel

Çetin

et al. 2022

Journal of Cellular Plastics

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Rigid polyurethane foams (RPUFs) were modified with 0–15 wt.% turkey feather fibers (TFFs) produced from waste turkey feathers. One-shut free rising method was used for the production of TFFs-filled-RPUFs in a closed mold. The dependence of mechanical performance and water vapor permeability (WVP) feature of the final foams on TFFs loading was evaluated with free volume change. The free volume analysis was performed via Positron Annihilation Lifetime Spectroscopy (PALS), while the mechanical and WVP characteristics were determined with the use of the universal tester machines. PALS findings showed that the incorporation of TFFs with RPUF matrix caused the considerable diminishment in the free volume due to TFFs serving as a filling material and formation of strong secondary bonds between components. Moreover, tensile strength and extension of the foams decreased with the increasing of TFFs, which caused by the occurrence of noteworthy restriction on the spatial alignment and orientation capability of polyurethane chains due to the lack of sufficient free volume allowing the chains to move freely. As for the compression tests, all the TFFs-loaded RPUFs depicted substantially lower performance due to TFFs interfering with the ordered organization of isocyanate domains. Moreover, impact test results showed that the addition of TFFs into RPUF matrix brought about the insufficient impact energy delocalization throughout the matrix due to the restriction on the mobility of polymer chains. Additionally, the remarkable diminishment in WVP was recorded due to the reduction in the number of vacancies and constitution of keratin composed of roundly 60% of hydrophilic protein (especially cystine). All in all, this study established a strong links between free volume and characteristics of TFFs-loaded RPUFs.

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Section: Introductionmentioning

confidence: 99%

Investigation of the relation between free volume and physico-mechanical performance in rigid polyurethane foam containing turkey feather fibers: Part 2

Soykan

Khaleel

Çetin

et al. 2022

Journal of Cellular Plastics

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“…Then, the zero shear viscosity equation developed by the YDT equation (Dinc et al, 2014;Sahin-Dinc, 2015;Sahin-Dinc et al, 2015) is used to link the linear viscosity of PPs in two tactic forms with thermooccupancy function including a vacancy fractional parameter determined through the Simha Somcynsky (SS) theory. The role of stereochemistry effects induced by chain tacticity on the rheological behavior of two stereoisomer forms of PPs, namely iPP and sPP, are elucidated in each part of the study.…”

Section: Introductionmentioning

confidence: 99%

İzo- ve Sindiyotaktik Polipropilenlerin Reolojik Davranışının Karşılaştırılması

Dinc

2022

Karadeniz Fen Bilimleri Dergisi

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The rheological behavior of iso- and syndiotactic polypropylenes (iPP and sPP) for two different temperatures of 175 and 190˚C at atmospheric pressure is analyzed employing the Yahsi-Dinc-Tav (YDT) non-Newtonian viscosity model. The predicted viscosity with shear rates of 0.093 to 93.91 s-1 on PPs is compared with the corresponding estimations from the Cross-like model. The obtained results from the YDT model deviate from the reported experimental observations with 1.041 for iPP and 1.86 for sPP. From the zero shear viscosity correlation to temperature- and vacancy fraction- dependent thermo-occupancy function, Yh = Yh(h, T), viscosity parameters were ascertained and associated with polymer tacticity. From the zero shear viscosity relation, an increase in Yh = Yh(h, T) function and hole fraction loss results in increased viscosity. The dependence of the derivative of logarithm of viscosity (viscoholibility) on vacancy fraction, as a function of pressure and temperature, h=h(P,T), procured from Simha-Somcynsky hole theory displays an exponentially decreasing behavior.

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“…Open spaces called "free volume" exist in the polymer structure as the chemical form changes. The free volume model of a polymer can explain several critical physical phenomena such as viscosity [14][15][16][17][18][19][20][21], ionic conductivity [22,23], relaxation [24], glass transition temperature, and other mechanical and thermodynamic properties. Several techniques such as X-ray or neutron scattering, differential scanning calorimetry, electron microscopy, dynamic mechanical study, and Fourier transform infrared spectroscopy can be utilized to measure the free volume of a polymer and to indirectly provide knowledge of the free volume of polymers and their composites [25].…”

Section: Introductionmentioning

confidence: 99%

Effect of Free Volume on Curcumin Release from Various Polymer-Based Composite Films Analyzed Using Positron Annihilation Lifetime Spectroscopy

et al. 2021

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This work reports the effects of free volume on curcumin release in various polymer-based composite films. Curcumin-reinforced biocomposite films were fabricated with natural biopolymers (carrageenan and chitosan) and bioplastics (poly(lactide) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT)) via the solvent casting method. The curcumin release test was performed using an aqueous medium, and it was found that it was released the fastest in the carrageenan film, followed by the chitosan, PLA, and PBAT films, presumably owing to the dissimilarity of the polymer matrix. The free volume of the polymer films was determined using positron annihilation lifetime spectroscopy (PALS) to understand the release phenomena of curcumin. The free volume fraction was varied and reliant on the type of polymer, with the highest in the PBAT-based film followed by the PLA-, chitosan-, and carrageenan-based films. The free volume method helps analyze the release of bioactive compounds in a polymer matrix and may help to achieve a better understanding of the release of bioactive compounds.

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Hole Fraction Dependence on Linear Viscosity of PS, PP and ABS

Cited by 8 publications

References 18 publications

Investigation of the relation between free volume and physico-mechanical performance in rigid polyurethane foam containing turkey feather fibers: Part 2

Investigation of the relation between free volume and physico-mechanical performance in rigid polyurethane foam containing turkey feather fibers: Part 2

İzo- ve Sindiyotaktik Polipropilenlerin Reolojik Davranışının Karşılaştırılması

Effect of Free Volume on Curcumin Release from Various Polymer-Based Composite Films Analyzed Using Positron Annihilation Lifetime Spectroscopy

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