DSC, TGA and dielectric properties of carboxymethyl cellulose/polyvinyl alcohol blends

El-Sayed, S.; Mahmoud, Khaled H.; Fatah, Ahmed; Hassen, A.

doi:10.1016/j.physb.2011.07.050

Cited by 266 publications

(115 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The lowering of the decomposition temperature of PEMs is attributed to the formation of free radicals at weak bonds and/or chain ends which further transfers to the adjacent chains through inter-chain reactions [14]. The weight loss of PEMs above 300°C is due to the decomposition of In the thermogram of pure PVA, the glass transition temperature is observed at 84°C, which is in good agreement with the T g value reported in the literature [12,15]. The DSC thermogram of pure PVA also shows an endothermic peak at~130°C.…”

Section: Resultssupporting

confidence: 87%

“…where, ΔH m is the heat of melting of the PEMs and ΔΗ m o is the heat of melting of 100% crystalline PVA (138.6 J/g) [12]. The calculated crystallinity is given in 4 ].…”

Section: Resultsmentioning

confidence: 99%

“…4a) shows a weight loss in the temperature range of 80-200°C followed by another weight loss in the temperature range of 240-460°C. PVA is a hydrophilic polymer; therefore the loss in the initial temperature range (80-200°C) is attributed to the evaporation of bonded water absorbed in the PVA network while the loss in the temperature range of 240-460°C is attributed to the decomposition of the polymer [12]. After incorporation of [BMIM][HSO 4 ], the TGA curves of PEMs (Fig.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Poly(vinyl)alcohol/1-butyl-3-methylimidazolium hydrogen sulfate solid polymer electrolyte: Structural and electrical studies

2015

View full text Add to dashboard Cite

Section: Resultssupporting

confidence: 87%

“…where, ΔH m is the heat of melting of the PEMs and ΔΗ m o is the heat of melting of 100% crystalline PVA (138.6 J/g) [12]. The calculated crystallinity is given in 4 ].…”

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Poly(vinyl)alcohol/1-butyl-3-methylimidazolium hydrogen sulfate solid polymer electrolyte: Structural and electrical studies

2015

View full text Add to dashboard Cite

“…The spacing of the cellulose chains in the CEF structure that are predicted from the simulations correlate with previously published WAXS 31 and x-ray diffraction data 32 . Furthermore, the crystalline conformation of the 18-and 24-chain models are in better agreement with high temperature molecular dynamic simulations produced by Matthews et al 33 .…”

Section: Cellulosesupporting

confidence: 84%

Bio-tribology of plant cell walls: measuring the interactive forces between cell wall components

Dolan¹

View full text Add to dashboard Cite

Plants have naturally evolved complex cell wall structures to give mechanical and friction properties that facilitate plant growth and development. A biomimetic approach is employed to gain insight into how plants are able to lubricate moving surfaces at multiple length scales. The outcomes of this study advance the fundamental scientific understanding of plant cell wall biology.New insights provided here may have significant implications for optimising the value of plant material as a food source, biofuel precursor, and as a model for functional biomaterial design, particularly for medical applications. A review of the plant cell wall structure, mechanics, and extension processes is used to identify the forces and tribological contacts that are relevant for plant growth. Plant cell walls are essentially hydrogel composites of cellulose fibres within a matrix of biopolymers (e.g. hemicelluloses, pectin) and water. Plant tissue is comprised of a cluster of plant cells where adjacent cell walls are mediated by a pectin rich middle lamella layer. Plant growth is initiated by expansins which are proteins that disrupt cellulose fibre contact points, leading to the extension of the cell wall matrix. As cells expand within the tissue structure, a sliding contact forms between adjacent walls that are extending at different rates. The two critical length scales that are considered here to influence plant growth are the contact between cellulose nano-fibres in the cell wall matrix, and the sliding interface between adjacent cell walls.A large component of this thesis is the development of techniques to mimic the two tribological contacts; that is, fibre-fibre and cell-cell interactions. The sliding interface between two surfaces is achieved using a rotational rheometer, which also allows in situ material characterisation of the surfaces with pre-compression, relaxation, and oscillatory shear mechanical testing steps. The interactive forces between nano-fibres are measured directly using an Atomic Force Microscope (AFM) tip to laterally pull fibres out of a network. Bacterial cellulose networks are used as a model system that is compatible with the developed techniques. Bacterial cellulose is a good model because of the structural similarity to plant cellulose, and its ability to grow as a self-assembled random fibre network with the shape and dimensions controlled by the vessel within which it is grown. The lubricating role of individual cell wall components at the two tribological contacts is examined; including arabinoxylan (AX), xyloglucan (XG), pectin, and expansins. This is achieved ii by growing composite bacterial cellulose networks with AX and XG, and by adding pectin or expansin solutions to the liquid medium surrounding the pre-formed cellulose networks during testing.The unique aspect of this mechanical study is that the experimental results are analysed using computation modelling. Appropriate models are used to simulate the behaviour of fibrous assemblies at multiple length scales, and under condition...

show abstract

“…Electrical properties of various polymer blends have been investigated by different researchers [22][23][24]. The dielectric properties of heterogeneous polymer materials play an important role in device applications such as high performance capacitor, electrical cable insulation, electronic packaging and components.…”

Section: Introductionmentioning

confidence: 99%

Dielectric properties and AC conductivity studies of novel NR/PVA full-interpenetrating polymer networks

Johns

Nakason

Praveen

2012

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

DSC, TGA and dielectric properties of carboxymethyl cellulose/polyvinyl alcohol blends

Cited by 266 publications

References 42 publications

Poly(vinyl)alcohol/1-butyl-3-methylimidazolium hydrogen sulfate solid polymer electrolyte: Structural and electrical studies

Poly(vinyl)alcohol/1-butyl-3-methylimidazolium hydrogen sulfate solid polymer electrolyte: Structural and electrical studies

Bio-tribology of plant cell walls: measuring the interactive forces between cell wall components

Dielectric properties and AC conductivity studies of novel NR/PVA full-interpenetrating polymer networks

Contact Info

Product

Resources

About