Thermal stability of polyvinyl alcohol/nanocrystalline cellulose composites

AbstractThe effect of nanocrystalline cellulose dispersion on the nonisothermal crystallization of poly(ethylene 2,5-furandicarboxylate) (PEF) has been investigated by means of solvent casting. The cellulose dispersion plays a significant role on the crystallization temperature, thus dispersive equipments of increasing energies were employed to improve the cellulose particles disaggregation. Therefore, ultra-sonic bath, ultra-sonication, and ultra-turrax were used to disperse cellulose nanocrystals in 1,1,1,3,3,3-hexafluoro-2-propanol. Dissolved separately in the same solvent, PEF was then poured into the cellulose suspension before casting. The cellulose whiskers were inspected by transmission electron microscopy. Differential scanning calorimetry was used to measure the crystallization temperature, while scanning electron microscopy visualized the cellulose dispersion at the fracture surface. After investigation on the interaction of cellulose/PEF via Fourier transform infrared spectroscopy, the thermal stability of the blends was measured by means of thermogravimetric analysis.

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Blends of synthetic plastic-derived polypeptide with Hydroxypropylmethylcellulose and polyvinyl alcohol: unraveling the specific interaction parameters, morphology and thermal stability of the polymers couple

Journal of Polymer Research ◽

10.1007/s10965-020-02191-5 ◽

2020 ◽

Vol 27 (9) ◽

Author(s):

B Mahesh ◽

D Kathyayani ◽

D Channe Gowda ◽

K Mrutunjaya

Keyword(s):

Thermal Stability ◽

Polyvinyl Alcohol ◽

Specific Interaction ◽

Interaction Parameters ◽

Thermal Stability Of

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Preparation of polyaniline-polyvinyl alcohol-silver nanocomposite and characterization of its mechanical and antibacterial properties

Science and Engineering of Composite Materials ◽

10.1515/secm-2016-0329 ◽

2018 ◽

Vol 25 (5) ◽

pp. 975-982 ◽

Cited By ~ 1

Author(s):

Alireza Khoshkbar Sadeghi ◽

Maryam Farbodi

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Polyvinyl Alcohol ◽

Nanocomposite Film ◽

Antibacterial Properties ◽

Composition And Structure ◽

Reinforcing Agent ◽

Silver Nanocomposite ◽

Thermal Stability Of

AbstractIn the present research, polyaniline is used as a conducting polymer and polyvinyl alcohol is also used as a biopolymer, because of its mechanical properties and suitable processability. Also, silver nanoparticles are considered as a reinforcing agent of thermal stability, mechanical and antibacterial properties to prepare polyaniline-polyvinyl alcohol-silver nanocomposite. The synthesis of polyaniline-polyvinyl alcohol composite and polyaniline-polyvinyl alcohol-silver nanocomposite is performed through addition of polyaniline and silver in polyvinyl alcohol solution. In order to review thermal, mechanical and antibacterial properties of synthesized composite and nanocomposites, components with different weight rates are used. The obtained results from thermogravimetric analysis (TGA) tests also indicate promotion of thermal stability of polyaniline-polyvinyl alcohol-silver nanocomposite compared with pure polyvinyl alcohol in temperatures above 400°C. The results of Fourier-transform infrared (FTIR) spectroscopy revealed the presence of polyaniline, polyvinyl alcohol and silver in the structure of polyaniline-polyvinyl alcohol-silver triple nanocomposite film. The obtained results from a review of antibacterial properties showed that polyaniline-polyvinyl alcohol-silver nanocomposites have antibacterial effects on two different types of Gram-positive and Gram-negative bacteria. The obtained results from a review of mechanical properties of nanocomposites showed that the greatest value of tensile strength (13.8 MPa) belonged to polyaniline-polyvinyl alcohol-silver (88%/9%/3% w/w) nanocomposites. Therefore, this is determined as an optimal triple nanocomposite. In addition, scanning electron microscopy (SEM) coupled with an energy dispersive X-ray (EDX) system was used to characterize the composition and structure of polyaniline-polyvinyl alcohol-silver nanocomposite film.

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Effects of polyethyleneimine-functionalized MCM-41 on flame retardancy and thermal stability of polyvinyl alcohol

Particuology ◽

10.1016/j.partic.2014.04.004 ◽

2015 ◽

Vol 19 ◽

pp. 14-21 ◽

Cited By ~ 13

Author(s):

Meisam Shabanian ◽

Mehdi Khoobi ◽

Farideh Hemati ◽

Hossein Ali Khonakdar ◽

Khalil Faghihi ◽

...

Keyword(s):

Thermal Stability ◽

Polyvinyl Alcohol ◽

Flame Retardancy ◽

Thermal Stability Of ◽

Mcm 41

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Heterogeneous Preparation of Polyaniline-Cellulose Conductive Composites with Cellulose Pretreated by Ultrasonic and its Electrical Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.1543 ◽

2009 ◽

Vol 79-82 ◽

pp. 1543-1546 ◽

Cited By ~ 1

Author(s):

Zhong Li Zhao ◽

Zun Li Mo ◽

Chao Feng ◽

Jun Wang

Keyword(s):

Thermal Stability ◽

Electrical Conductivity ◽

Chemical Structure ◽

Ultrasonic Pretreatment ◽

Homogeneous Dispersion ◽

Conductive Composites ◽

Native Cellulose ◽

Cellulose Composites ◽

Cellulose Surface ◽

Thermal Stability Of

A series of conductive composites polyaniline(PANI)-cellulose were heterogeneously synthesized by chemical oxidative polymerization of aniline with native cellulose pretreated by ultrasonic. The morphology and chemical structure of the composites were examined by SEM and FTIR. TGA was used to study their thermal properties. The electrical conductivity was measured at room temperature by the standard four-probe method. For the sake of illuminating the influence of ultrasonic pretreatment on the structure and properties of PANI-cellulose composites, the SEM microphotographs, FTIR spectrum and TG curve of the PANI-cellulose composites prepared with native cellulose without any treatment were also shown in this paper to serve as reference. The PANI content and electrical conductivity of these two composites were also compared. It was found that cellulose surface was severely eroded by ultrasonic wave, and PANI homogeneously dispersed on this eroded cellulose surface in the form of particles. In reverse, the PANI particles loaded on the surface of untreated cellulose with evident aggregation. The homogeneous dispersion of PANI particles would be favor for the improvement of the electrical conductivity of the composites. From the FTIR spectra, it was verified that there was no difference between these two composites. It indicated that ultrasonic force did not lead to the variation of the chemical structure of cellulose. TG curves revealed that the thermal stability of PANI-cellulose composites was obviously enhanced than pure cellulose due to the protection of PANI particles deposited on its surface. Nevertheless, ultrasonic has a negative effect on the thermal stability of the composites, which resulted in the long cellulose molecular chains change into shorter ones, so the decomposition of composite occurred at lower temperature. It was because that ultrasonic pretreatment contributed to the homogeneous dispersion of PANI and more PANI particle depositing on the cellulose surface. Therefore, the PANI-cellulose composites with ultrasonic pretreated cellulose have more PANI content and higher electrical conductivity than the composites with untreated cellulose. Moreover, the difference of these two factors between the two composites became more and more marked with increasing of the amount of aniline. When aniline used was up to 0.5 g, the PANI content in the former was 48.2% more than the latter. This work provided a facile method for the synthesis of PANI-cellulose conductive composites with excellent conductivity.

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Thermal Conductivity of Poplar Wood Veneer Impregnated with Graphene/Polyvinyl Alcohol

Forests ◽

10.3390/f12060777 ◽

2021 ◽

Vol 12 (6) ◽

pp. 777

Author(s):

Shuang-Shuang Wu ◽

Xin Tao ◽

Wei Xu

Keyword(s):

Thermal Conductivity ◽

Thermal Stability ◽

Polyvinyl Alcohol ◽

Weight Percent Gain ◽

Chromatic Aberration ◽

Weight Percent ◽

Poplar Wood ◽

Wood Veneer ◽

Optimal Sample ◽

Thermal Stability Of

Intending to achieve more green and economical graphene impregnated modified fast-growing poplar wood veneer for heat conduction, this study proposes and investigates the feasibility of modified veneer with graphene/Polyvinyl alcohol (Gr/PVA) impregnation mixture to improve its thermal conductivity. The absorbance and viscosity of the Gr/PVA impregnation mixtures are observed to expound the Gr/PVA ratio effects on the mixtures. Simultaneously, the weight percent gain, chromatic aberration, and thermal conductivity of the modified veneers are measured to determine the impregnation effect and the optimal impregnation formula. Further, the chemical structure, crystallinity, and thermal stability of the optimal sample impregnated with Gr/PVA are tested. The results show that the thermal properties of the Gr/PVA impregnated modified veneer have not all been improved. Still, both the dispersibility of the impregnation mixtures and the impregnation effect is affected by the Gr/PVA ratio. The data shows that the optimal thermal conductivity of modified veneer, which is up to 0.22 W·m−1·K−1 and 2.4 times the untreated one, is dipped by the mixture of 10 wt.% PVA concentration and 2 wt.% MGEIN addition. According to the characterization tests, the crystallinity of the modified veneer reduces, but the thermal stability improves.

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