Thermal and structural studies of poly (vinyl alcohol) and hydroxypropyl cellulose blends

Guirguis, Osiris W.; Moselhey, Manal T. H.

doi:10.4236/ns.2012.41009

Cited by 161 publications

(113 citation statements)

References 25 publications

(27 reference statements)

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“…The small broad endothermic peak characteristic of glass transition temperature of HPC and/or may be due to the loss of hydrated and coordinated water molecules, which come from the ambient environment. Similar result was observed for PVA/HPC blend by Guirguis et al [27]. Gomez-Carracdo et al [28] reported that the T g of pure HPC is about 105°C but in the present system when blended with PVDF, the T g decreases to 70°C.…”

Section: 22supporting

confidence: 91%

The effect of nanographite addition on the physical properties of poly(vinylidene fluoride)/hydroxypropyl cellulose blend

Abdelaziz

Abdelrazek

2014

J Mater Sci: Mater Electron

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In this study, polymeric films of poly(vinylidene fluoride) (PVDF)/hydroxypropyl cellulose (HPC) blend filled with various graphite-nanoparticles (GNP) contents were prepared via solvent-mixing technique. The compatibility between PVDF and HPC polymers was studied. The variations in structure, dielectric and thermal properties were investigated over the frequency range (20 Hz-3 MHz) and temperature range (20-110°C). The X-ray diffraction and differential scanning calorimetry results reveal that the crystallinity of PVDF was affected by the presence of HPC and GNP. The dielectric results reveal that the great enhancement of dielectric constant (e 0 ) and ac conductivity (r ac ) were observed. The dielectric properties were explained in terms of the dielectric polarization mechanism. Both HPC and GNP additions enhance the e 0 of PVDF due to the formation of b-phase polymorph and the interface effect between the GNP and blend matrix. The improvement of the thermal stability was observed due to the regular arrangement of the side chains. The easy processing, high dielectric constant, low tangent loss and high thermal stability of the composites make the composites attractive for practical applications in embedded capacitors.

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Section: 22supporting

confidence: 91%

The effect of nanographite addition on the physical properties of poly(vinylidene fluoride)/hydroxypropyl cellulose blend

Abdelaziz

Abdelrazek

2014

J Mater Sci: Mater Electron

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“…Cellulose is therefore low cost, innocuous and biodegradable. HPC has previously been considered as a suitable biopolymer for thermotropic glazing both independently [15,16] and as part of an interpolymer complex [17][18][19]. In addition, HPC is water-soluble due to the substitution of reactive hydroxyl groups on the cellulose structure with hydrophobic hydroxypropyl groups which results in weakened intermolecular hydrogen bonding within the cellulose [20].…”

Section: Introductionmentioning

confidence: 99%

Transmittance and Reflectance Studies of Thermotropic Material for a Novel Building Integrated Concentrating Photovoltaic (BICPV) ‘Smart Window’ System

Connelly

et al. 2017

Energies

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Abstract:A novel Building Integrated Concentrating Photovoltaic (BICPV) Smart Window has been designed and developed as a next generation intelligent window system. In response to climatic conditions, the smart window varies solar light transmission into the building for provision of light and heat with the reflection of light to the photovoltaic (PV) for electricity generation. This unique function is realised using an integrated thermotropic layer in conjunction with embedded PVs. As commercial PVs are readily available, the success of this novel BICPV design depends solely on the performance of the thermotropic material. This study aimed to develop a suitable reflective thermotropic layer for the proposed smart Concentrating Photovoltaic (CPV) system. A Hydroxypropyl cellulose (HPC) polymer was tested for its applicability as a potential reflective thermotropic material for this purpose. HPC concentration was systematically varied from 1 wt. % to 6 wt. % in aqueous solution so as to provide insight into the relationship between transmittance/reflectance properties, the concentration of the thermotropic material and their dependence upon the environmental temperature. The degree of hysteresis of light transmittance upon subjecting HPC to heating and cooling cycles was also investigated. Specifically, for the HPC liquid samples the measured threshold temperature/transition temperature (T s ) was observed to be approximately 40 • C for 6 wt. % HPC, increasing to approximately 44 • C for 1 wt. % HPC. No hysteresis was observed upon heating and cooling HPC samples. Reflectance below the T s was recorded at~10%, increasing up to~70% above the T s for 6 wt. % HPC. Finally, a HPC-based hydrogel membrane sample was developed and exhibited good thermotropic activity therefore demonstrating its suitability for use within the BICPV smart window. This study corroborates that HPC is a suitable thermotropic material in the application of next generation BICPV smart window systems.

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“…XRD spectra patterns of crystalline polymers may be used to extract qualitative information on the degree of crystallinity of polymers and blends [17,20]. In this study, XRD spectra of neat PHP /PBA and their blend films shown in Figure 4 were obtained to understand the effect of blending on the degree of crystallinity of each component.…”

Section: X-ray Diffraction Spectroscopymentioning

confidence: 99%

MISCIBILITY AND THERMAL DEGRADATION KINETICS OF POLY-β-ALANINE/POLY(3-HYDROXYPROPIONATE) BLENDS

Çatıker

Basan

2016

Journal of the Turkish Chemical Society, Section A: Chemistry

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Poly-β-alanine (PBA) and poly(3-hydroxypropionate) (PHP) were synthesized via base-catalyzed hydrogen transfer polymerization (HTP) of acrylamide and acrylic acid, respectively. Blends of PBA/PHP with different composition (PHP content, 5% to 75%) were studied using FTIR, DSC, TGA, XRD and polarized optical microscope to reveal both miscibility and thermal degradation kinetics of PBA/PHP blends. Optical images of blends were transparent and entirely uniform. Characteristic FTIR bands of both components shifted in higher frequencies with increasing fraction of another component. Melting temperature (Tm), thermal decomposition temperatures (Td), and enthalpy of fusion (ΔHf) of PHP decreased with increasing PBA fraction in blends. Thermal degradation kinetics of both components were studied by Freeman-Carroll method. Activation energies of thermal degradations of blend components were determined with good regression coefficients (at least 0.994). Activation energies of decomposition decreased from 224.14 to 86.125 kJmol -1 with increasing PHP content. XRD spectra of blends exhibited lower peak intensities than those of neat polymers. The spectroscopic, thermal, and optical methods revealed that PBA and PHP were miscible with a good compatibility in amorphous phase.

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Thermal and structural studies of poly (vinyl alcohol) and hydroxypropyl cellulose blends

Cited by 161 publications

References 25 publications

The effect of nanographite addition on the physical properties of poly(vinylidene fluoride)/hydroxypropyl cellulose blend

The effect of nanographite addition on the physical properties of poly(vinylidene fluoride)/hydroxypropyl cellulose blend

Transmittance and Reflectance Studies of Thermotropic Material for a Novel Building Integrated Concentrating Photovoltaic (BICPV) ‘Smart Window’ System

MISCIBILITY AND THERMAL DEGRADATION KINETICS OF POLY-β-ALANINE/POLY(3-HYDROXYPROPIONATE) BLENDS

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