Free-volume properties of epoxy composites and its relation to macrostructure properties

Asaad, J. N.; Gomaa, Eman Zakaria; Bishay, I. K.

doi:10.1016/j.msea.2008.03.015

Cited by 21 publications

(19 citation statements)

References 23 publications

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“…It has been well established that in polymeric systems, macroscopic properties such as tensile strength, modulus, and toughness depends on the microstructural properties of the system. This microstructural property in the present case is free volume cavities and their concentration, which had been used in understanding visco‐elastic properties of many polymeric systems 18–23, 25–33. This property depends on chain morphology of the system i.e.…”

Section: Resultsmentioning

confidence: 92%

Positron Lifetime Spectroscopy and Differential Scanning Calorimetric study of polystyrene‐based composites with fly ash, cenospheres, and calcium aluminosilicate as fillers

Altaweel

Ranganathaiah

Siddramaiah³

2010

J of Applied Polymer Sci

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Polystyrene-based composites with Fly ash, Cenospheres, and Calcium aluminosilicate as fillers have been examined for their mechanical and microstructure properties. Free volume measurements have been carried out using Positron Lifetime Spectroscopy to probe the microstructural features of the composites. Incorporation of fly ash, cenospheres, and calcium aluminosilicate improved the thermal properties of the composites due to increased T g of the composites as revealed by the DSC data. Also, it was observed that the mechanical properties of calcium aluminosilicate filled composites improved more compared to fly ash and cenospheres filled composites. We attribute these favorable changes to the higher silica content of calcium aluminosilicate on account of possible interactions between the polymer matrix and silica and to some extent from particulate size.

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Section: Resultsmentioning

confidence: 92%

Positron Lifetime Spectroscopy and Differential Scanning Calorimetric study of polystyrene‐based composites with fly ash, cenospheres, and calcium aluminosilicate as fillers

Altaweel

Ranganathaiah

Siddramaiah³

2010

J of Applied Polymer Sci

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“…The third lifetime (τ 3 ) can by associated with the o ‐Ps annihilation within crystalline phase of the polymer and the fourth lifetime (τ 4 ) may be attributed to the o ‐Ps pick‐off annihilation in the amorphous region . Moreover, the o ‐Ps lifetimes (τ) and their intensities (I) give the information about the size and number of free‐volume holes, respectively . In the case of polymer composites, the values of τ and I were found to be dependent mostly on the type and content of the filler used as well as the kind of the polymer .…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, the o ‐Ps lifetimes (τ) and their intensities (I) give the information about the size and number of free‐volume holes, respectively . In the case of polymer composites, the values of τ and I were found to be dependent mostly on the type and content of the filler used as well as the kind of the polymer .…”

Section: Resultsmentioning

confidence: 99%

Functionalized siloxane‐silsesquioxane resins and polypropylene‐based composites: Morphological, structural, thermal, and mechanical properties

et al. 2018

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Non‐functionalized and n‐alkyl‐functionalized siloxane‐silsesquioxane resins (S4SQ) were synthesized and characterized to confirm their structure and properties. Polypropylene (PP) composites with S4SQ resins as fillers were prepared by the melt blending. The influence of the kinds and amounts of fillers on the structural, morphological and thermal properties as well as mechanical characteristics and processability was determined. High compatibility of composites with functionalized resins resulted in more homogenous dispersion of filler particles in comparison with the composites which contained a non‐functionalized resin. Moreover, the introduction of S4SQ resins into PP strongly affected the crystalline structure of the polymer matrix and the free‐volume properties of composites. Siloxane‐silsesquioxane resins changed the contributions of the α‐ and β‐crystalline phases and they increased the crystal sizes of PP. The PP/S4SQ composites were also characterized by the improved crystallization temperature and crystallinity degree while the melting temperature and processability were changed only slightly. The mechanical properties of the PP/S4SQ materials were found to be dependent mostly on the degree of filler dispersion and crystalline structure of the composite materials. POLYM. COMPOS., 40:3101–3114, 2019. © 2018 Society of Plastics Engineers

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“…Studies of the microscopic free-volume properties at molecular and atomic scales can provide a basic understanding of the mechanical and physical properties of polymers [10]. Free-volume theories about the glass transition assume that if the conformational changes of the backbone are to take place, there must be enough space available for the molecular segment to move into.…”

Section: Description Of the Simulationsmentioning

confidence: 99%

Study on the gas permeabilities in styrene-butadiene rubber by molecular dynamics simulation

Liu

Ding

et al. 2009

Front. Chem. Eng. China

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In this research, molecular dynamics (MD) simulations were used to study the transport properties of small gas molecules in the butadiene-styrene copolymer (SBR). The condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field was applied. The diffusion coefficients were obtained from MD (NVT ensemble) and the relationship between gas permeability; the chemical structure and free volume of butadiene-styrene copolymer were investigated. The results indicated that the diffusion coefficient of oxygen declined with increasing styrene content. The fraction of free volume (FFV) in butadiene-styrene copolymer was calculated. It was concluded that diffusion coefficient increased as the FFV increases, which is in accordance with the analysis of the small molecular hop through the free volume in polymer matrix. Subsequently, the glass transition temperatures of these copolymers were calculated by MD. The result showed that the glass transition temperature increased with increasing styrene content in polymer.

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Free-volume properties of epoxy composites and its relation to macrostructure properties

Cited by 21 publications

References 23 publications

Positron Lifetime Spectroscopy and Differential Scanning Calorimetric study of polystyrene‐based composites with fly ash, cenospheres, and calcium aluminosilicate as fillers

Positron Lifetime Spectroscopy and Differential Scanning Calorimetric study of polystyrene‐based composites with fly ash, cenospheres, and calcium aluminosilicate as fillers

Functionalized siloxane‐silsesquioxane resins and polypropylene‐based composites: Morphological, structural, thermal, and mechanical properties

Study on the gas permeabilities in styrene-butadiene rubber by molecular dynamics simulation

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