Photodegradation of poly(ethyleneoxide)/montmorillonite composite films

Lombardo, Patricia Coelho; Poli, Alessandra Lima; Neumann, Miguel G.; Machado, Douglas Silva; Cavalheiro, Carla Cristina Schmitt

doi:10.1002/app.37987

Cited by 11 publications

(13 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…No trabalho anterior foi discutido em detalhes os espectros de FTIR de filmes de PEO com argila montmorilonita SWy-1 [8] .…”

Section: Caracterização Por Ftirunclassified

“…A argila SWy-1 pode ser considerada como estabilizante contra irradiação UV [7,8] . O modo de estabilização da argila pode ser explicado devido à capacidade da argila não só 4.…”

Section: Tabelaunclassified

“…O modo de estabilização da argila pode ser explicado devido à capacidade da argila não só 4. Cromatogramas de SEC do PEO puro antes e após a irradiação para espalhar a luz incidente, mas também para absorver parte da luz UV como discutido em artigo anterior [8] . O espectro de absorção da argila SWy-1 mostra banda em 242 nm, atribuída a uma transição de transferência de carga (Fe 3+ octaedral) [31] .…”

Section: Tabelaunclassified

“…Os danos causados pela foto-oxidação de materiais poliméricos também são aplicados aos materiais compósitos do tipo polímero/argila, no entanto, apesar de existir vários relatos na literatura a respeito de polímeros/silicatos, pouca atenção tem sido dada ao seu comportamento durante a fotodegradação [7][8][9][10] . Em geral, os estudos de processos foto-oxidativos de materiais compósitos polímero/argila mostram que a presença da argila acelera os processos de degradação dos mesmos quando comparados ao polímero puro [11][12][13] .…”

Section: Introductionunclassified

See 3 more Smart Citations

Influência de estabilizantes na degradação foto-oxidativa de filmes de compósitos de SWy-1/poli(óxido de etileno)

2015

View full text Add to dashboard Cite

ResumoCompósitos de poli(óxido de etileno) (PEO) com argila montmorilonita SWy-1 e estabilizantes (2-hidroxibenzofenona e tinuvin 770) foram preparados pelo método de intercalação em solução. Os filmes obtidos foram expostos a irradiação UV, e os produtos da fotodegradação foram monitorados por FTIR (Fourier Transform Infrared Spectroscopy, ou Espectroscopia no infravermelho por transformada de Fourier) e SEC (Size Exclusion Chromatography, ou cromatografia de exclusão por tamanho). O PEO puro apresentou maior coeficiente de degradação, k d, comparado com as demais amostras. O sistema que apresentou o menor valor para o coeficiente de degradação (k d = 1,9×10-6 mol g -1 h -1 ) foi o compósito de PEO/5%SWy-1 com 0,25% de tinuvin 770. Nesse caso, a estabilização da matriz de PEO pode ser atribuída à argila juntamente com o tinuvin 770. A argila dispersa e absorve a irradiação UV, e o tinuvin age como estabilizante do tipo HALS (do inglês hindered amine light stabilizer, ou estabilizantes à luz tipo aminas impedidas). Palavras-chave: poli(óxido de etileno), montmorilonita, fotoestabilizantes, degradação foto-oxidativa. AbstractPoly(ethylene oxide) (PEO) with SWy-1 montmorillonite and stabilizers (2-hydroxybenzophenone and tinuvin 770) composites were prepared by intercalation in solution method. The films of the composites were exposed to UV irradiation. The photodegradation products were monitored by FTIR (Fourier Transform Infrared Spectroscopy) and SEC (Size Exclusion Chromatography) method. The PEO pure showed higher degradation rate coefficients, k d , compared to the others samples. The system that showed the lowest value for the degradation rate coefficients (k d = 1.9×10 -6 mol g -1 h -1 ) was the PEO/SWy-1 5% composite with 0.25% of tinuvin 770. In this case, the stabilization of the PEO matrix can be attributed to clay associated with tinuvin 770. The clay scatters and absorbs UV irradiation and tinuvin acts as a stabilizer of the HALS (hindered amine light stabilizers) kind.

show abstract

“…No trabalho anterior foi discutido em detalhes os espectros de FTIR de filmes de PEO com argila montmorilonita SWy-1 [8] .…”

Section: Caracterização Por Ftirunclassified

“…A argila SWy-1 pode ser considerada como estabilizante contra irradiação UV [7,8] . O modo de estabilização da argila pode ser explicado devido à capacidade da argila não só 4.…”

Section: Tabelaunclassified

Section: Introductionunclassified

See 2 more Smart Citations

Influência de estabilizantes na degradação foto-oxidativa de filmes de compósitos de SWy-1/poli(óxido de etileno)

2015

View full text Add to dashboard Cite

show abstract

“…In the last two decades, polymer nanocomposites (PNCs) have emerged a new class of materials due to not only scientific interest but also the remarkable improvement in the performance properties of host polymer matrix dispersed with extremely small amount of clay as inorganic nanofiller . Among the polymer nanocomposites, the poly(ethylene oxide) (PEO) dispersed with Na + –montmorillonite (abbreviated as MMT or Na + –MMT clay) layered has attracted special interest due to its many technical applications in the area of solid polymer electrolytes, pharmaceutical drugs, purification of biological materials, adhesives, packaging and surface coating films, friction reduction, thickening of water‐based paints, etc . The MMT has 2:1 charged phyllosilicate platelets of 1 nm thickness and these are stacked by weak dipolar or van der Waals forces which lead to the intercalation of polar molecules causing the crystal lattice to expand in the c ‐direction.…”

Section: Introductionmentioning

confidence: 99%

Intercalated clay structures and amorphous behavior of solution cast and melt pressed poly(ethylene oxide)–clay nanocomposites

Choudhary

Sengwa

2013

J of Applied Polymer Sci

View full text Add to dashboard Cite

The polymer nanocomposite (PNC) films consisted of poly(ethylene oxide) (PEO) and sodium cations montmorillonite (MMT) clay were prepared by aqueous solution casting and direct melt press compounding techniques, whereas the films of PEO with trimethyl octadecyl ammonium cations organo-modified montmorillonite (OMMT) clay were formed by melt pressed technique. The clay concentrations in the nanocomposites used are 1, 2, 3, 5, 10, and 20 wt % of the PEO weight. The X-ray diffraction patterns of these nanocomposites were measured in the angular range (2h) of 3.8-30 . The values of basal spacing d 001 of MMT/OMMT, clay gallery width W cg , d-spacings of PEO crystal reflections d 120 and d 112 , and their corresponding crystallite size L, and the peaks intensity I (counts) were determined for these nanocomposites. Results reveal that the nanocomposites have intercalated clay structures and the amount of intercalation increases with the increase of clay concentration. As compared to melt pressed PEO-MMT nanocomposites, the amount of clay intercalation is higher in aqueous solution cast nanocomposites. At 20 wt % MMT dispersion in PEO matrix, the solution cast PEO-MMT nanocomposite almost changes into amorphous phase. The melt press compounded PEO-OMMT films show more intercalation as compared to the PEO-MMT nanocomposites prepared by same technique. In melt pressed nanocomposites, the PEO crystalline phase significantly reduces when clay concentration exceeds 3 wt %, which is evidenced by the decrease in relative intensity of PEO principal crystalline peaks. The effect of interactions between the functional group (ethylene oxide) of PEO and layered sheets of clay on both the main crystalline peaks of PEO was separately analyzed using their XRD parameters in relation to structural conformations of these nanocomposites. V C 2013 Wiley Periodicals, Inc. J.Appl. Polym. Sci. 2014, 131, 39898.

show abstract

Structural characterization of hydrophilic polymer blends/montmorillonite clay nanocomposites

Sengwa

Choudhary

2014

J of Applied Polymer Sci

View full text Add to dashboard Cite

The nanocomposite films comprising polymer blends of poly(vinyl alcohol) (PVA), poly(vinyl pyrrolidone) (PVP), poly(ethylene oxide) (PEO), and poly(ethylene glycol) (PEG) with montmorillonite (MMT) clay as nanofiller were prepared by aqueous solution casting method. The X‐ray diffraction studies of the PVA–x wt % MMT, (PVA–PVP)–x wt % MMT, (PVA–PEO)–x wt % MMT and (PVA–PEG)–x wt % MMT nanocomposites containing MMT concentrations x = 1, 2, 3, 5 and 10 wt % of the polymer weight were carried out in the angular range (2θ) of 3.8–30°. The values of MMT basal spacing d001, expansion of clay gallery width Wcg, d‐spacing of polymer spherulite, crystallite size L and diffraction peak intensity I were determined for these nanocomposites. The values of structural parameters reveal that the linear chain PEO and PEG in the PVA blend based nanocomposites promote the amount of MMT intercalated structures, and these structures are found relatively higher for the (PVA–PEO)–x wt % MMT nanocomposites. It is observed that the presence of bulky ester‐side group in PVP backbone restricts its intercalation, whereas the adsorption behavior of PVP on the MMT nanosheets mainly results the MMT exfoliated structures in the (PVA–PVP)–x wt % MMT nanocomposites. The crystallinities of the PEO and PEG were found low due to their blending with PVA, which further decreased anomalously with the increase of MMT concentration in the nanocomposites. The decrease of polymer crystalline phase of these materials confirmed their suitability in preparation of novel solid polymer nanocomposite electrolytes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40617.

show abstract

Photodegradation of poly(ethyleneoxide)/montmorillonite composite films

Cited by 11 publications

References 37 publications

Influência de estabilizantes na degradação foto-oxidativa de filmes de compósitos de SWy-1/poli(óxido de etileno)

Influência de estabilizantes na degradação foto-oxidativa de filmes de compósitos de SWy-1/poli(óxido de etileno)

Intercalated clay structures and amorphous behavior of solution cast and melt pressed poly(ethylene oxide)–clay nanocomposites

Structural characterization of hydrophilic polymer blends/montmorillonite clay nanocomposites

Contact Info

Product

Resources

About