Chemical Modification of Poly(Vinyl Alcohol) in Water

Awada, Houssein; Daneault, Claude

doi:10.3390/app5040840

Cited by 130 publications

(86 citation statements)

References 24 publications

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“…The first decomposition at a temperature of 106 o C associated with the evaporation of water adsorbed. While decomposition on the second and third peaks related to the decomposition of the edge and the main chain of PVA, respectively (Awada & Daneault, 2015).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of porous hydroxyapatite scaffolds from waste cockle shells by polyurethane sponge replication method

et al. 2020

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Researchers have synthesized hydroxyapatite-based porous scaffolds by the polyurethane sponge replication methods. Hydroxyapatite was derived from waste cockle shells through the co-precipitation method. The synthesis of porous scaffolds through the sponge replication methods is carried out by absorbing hydroxyapatite slurry through the addition of PVA and then followed by heating at 900 o C to decompose the polyurethane and PVA. The best of slurry that can produce a porous scaffold in this study is the slurry that prepared through the ratio of hydroxyapatite:PVA = 80:20. The decomposition of the two polymers will leave macropores on the scaffold with an average size of 460 μm. Based on the thermogravimetric analysis, X-ray diffraction and FTIR spectrophotometer revealed that the PVA and polyurethane sponge were correctly decomposed, except for scaffolds with 40% PVA. Thus, the porous scaffolds synthesized in this study satisfies the requirements of porous scaffolds for the bone therapy process.

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Section: Resultsmentioning

confidence: 99%

Synthesis of porous hydroxyapatite scaffolds from waste cockle shells by polyurethane sponge replication method

et al. 2020

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“…We observed three inflexions at 207°C, 436°C, and 541°C related to three decomposition step of the PVA‐Alg. The first temperature is attributed to the breakage of side chain of the PVA and alginate while the second and third temperatures are related to the thermal decomposition of the main chain of them, which occurred at higher temperatures . The total residual ash for the PVA‐Alg, MPVA‐Alg, and TiO 2 /MPVA‐Alg samples were 23.8, 25.5 and 34.1 wt%, respectively, which reveals the stability of the TiO 2 /PVA‐Alg sample after modification by TMCS.…”

Section: Resultsmentioning

confidence: 99%

“…The first temperature is attributed to the breakage of side chain of the PVA and alginate while the second and third temperatures are related to the thermal decomposition of the main chain of them, which occurred at higher temperatures. 33 The total residual ash for the PVA-Alg, MPVA-Alg, and TiO 2 /MPVA-Alg samples were 23.8, 25.5 and 34.1 wt%, respectively, which reveals the stability of the TiO 2 /PVA-Alg sample after modification by TMCS. The TiO 2 particles were the nondecomposed/degraded compound at the temperature range below 800 C and remained in the sample in Rutile phase.…”

Section: Thermogravimetric Analysismentioning

confidence: 86%

Preparation of floatable TiO ₂ /poly(vinyl alcohol)‐alginate composite for the photodegradation of ammonia wastewater

2019

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Summary The use of floatable photocatalyst supports is an operable strategy of increasing photocatalytic performance in terms of improving light absorption. In this work, floatable organic support based on poly(vinyl alcohol) (PVA) was used to float commercial TiO2 P25 nanoparticles. At first, by the use of CaCl2 and boric acid at pH 3 the cross‐linking of PVA blended with sodium alginate (PVA‐Alg) was improved to enhance chemical and mechanical stability, and then it was chemically modified by trimethylchlorosilane to achieve floatable organic support (modified or MPVA‐Alg). The prepared support and photocatalyst were characterized by X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy, energy‐dispersive X‐ray spectroscopy (EDX)‐elemental mapping, inductively coupled plasma optical emission spectroscopy, ultraviolet‐visible (UV‐vis) diffuse reflectance spectroscopy, photoluminescence (PL), thermalgravimetry, Brunauer‐Emmett‐Teller (BET), and water contact angle (WCA) analyses and applied for the ammonia degradation under UV to visible regions. Results of WCA and FTIR confirmed that chemical modification of PVA‐Alg led to lowering hydrophilicity to be floated on the ammonia wastewater. UV‐vis analysis indicated that the MPVA‐Alg acts as a light absorbent in UV‐vis ranges and makes TiO2/MPVA‐Alg a visible light active composite. Also, the PL analysis showed that the charge recombination process was strongly suppressed in the case of the TiO2/MPVA‐Alg sample. BET theory suggested that the textural properties were not the key factor in determining photocatalytic performance. The maximum photocatalytic ammonia removal was obtained to be 63% and 57% by the TiO2/MPVA‐Alg composite under UV‐vis light irradiations, respectively. The MPVA‐Alg and TiO2 exhibited the ammonia degradation of 28.5% and 15.2% under visible and 29.4% and 40.0% under UV irradiation, respectively. The TiO2/MPVA‐Alg showed favorable reuse ability after five runs due to desirable chemical and mechanical resistance. This study provides an insight into the modification of polymeric structures to be used as both floatable photocatalyst support and light sensitizer.

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“…4. Taking into account the chemical structure of the PVA a broad peak around 3300 cm -1 corresponding to the OH hydroxyl bond is observed [25], a peak between 2920 cm -1 and 2840 cm -1 indicator of the symmetric and antisymmetric vibration of the CH bond [26], and the signal representative to the symmetric vibration of the CH2 group is found at the peak of 1419 cm -1 [27]. In addition, the linkage of the formyl group -CHO given by the formaldehyde provided by the crosslinking agent in 1740 cm -1 and 1720 cm -1 is observed [14].…”

Section: Analysis Ftirmentioning

confidence: 99%

Synthesis of a proton exchange membrane from polyvinyl alcohol (PVA) modified with Va2O5 for fuel cells

Alvaro¹,

Alfonso²,

Carlos³

et al. 2017

ces

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Proton exchange membranes were synthesized from the Polyvinyl Alcohol copolymer (PVA) crosslinked with potassium hydroxide (KOH) and formaldehyde (CH2O), and loaded with vanadium pentoxide in amounts of 0.5%, 1.0% and 1.5% to evaluate their application in fuel cells. The physicochemical and mechanical properties of the membranes were characterized. The results show that the membrane loaded at 1.5% presented the highest ion exchange capacity (1.1 meq/g) and a very good water retention, due to the optimum level of load achieved, allowing a correct interaction between the Va2O5 and the polymer matrix, while the 0.5% loaded one showed better mechanical properties (maximum stress of 35.9 MPa, maximum deformation of 218.9%, Young's modulus of 135.4 MPa) and the FTIR tests confirmed the presence of Va2O5 in the polymer. These results demonstrate adequate characteristics of the prepared membranes to be used in fuel cells.

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Chemical Modification of Poly(Vinyl Alcohol) in Water

Cited by 130 publications

References 24 publications

Synthesis of porous hydroxyapatite scaffolds from waste cockle shells by polyurethane sponge replication method

Synthesis of porous hydroxyapatite scaffolds from waste cockle shells by polyurethane sponge replication method

Preparation of floatable TiO ₂ /poly(vinyl alcohol)‐alginate composite for the photodegradation of ammonia wastewater

Synthesis of a proton exchange membrane from polyvinyl alcohol (PVA) modified with Va2O5 for fuel cells

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Chemical Modification of Poly(Vinyl Alcohol) in Water

Cited by 130 publications

References 24 publications

Synthesis of porous hydroxyapatite scaffolds from waste cockle shells by polyurethane sponge replication method

Synthesis of porous hydroxyapatite scaffolds from waste cockle shells by polyurethane sponge replication method

Preparation of floatable TiO 2 /poly(vinyl alcohol)‐alginate composite for the photodegradation of ammonia wastewater

Synthesis of a proton exchange membrane from polyvinyl alcohol (PVA) modified with Va2O5 for fuel cells

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Preparation of floatable TiO ₂ /poly(vinyl alcohol)‐alginate composite for the photodegradation of ammonia wastewater